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Can we IMPROVE cardiovascular outcomes through phosphate lowering in CKD? - Rationale for the IMpact of Phosphate Reduction On Vascular End-points in Chronic Kidney Disease (IMPROVE-CKD) study
ForJournal: peerBMJ Open review only
Manuscript ID bmjopen-2018-024382
Article Type: Protocol
Date Submitted by the Author: 24-May-2018
Complete List of Authors: Lioufas, Nicole; Royal Melbourne Hosp, Nephrology; University of Melbourne, Department of Medicine Toussaint, Nigel D.; Royal Melbourne Hosp, Nephrology; University of Melbourne, Department of Medicine Pedagogos, Eugenia; Epworth Healthcare Elder, Grahame; Westmead Hospital, Department of Renal Medicine; Garvan Institute of Medical Research, Osteoporosis and Bone Biology Division Badve, Sunil; St. George Hospital, Department of Nephrology
Pascoe, Elaine; University of Queensland, Faculty of Medicine; Australasian http://bmjopen.bmj.com/ Kidney Trials Network Valks, Andrea; Australasian Kidney Trials Network Hawley, Carmel; The University of Queensland, Faculty of Medicine; Princess Alexandra Hospital, Department of Nephrology
phosphate, mineral metabolism, randomized controlled trial, CKD-MBD, Keywords: pulse wave velocity, vascular calcification
on September 30, 2021 by guest. Protected copyright.
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1 1 2 3 th 4 24 May 2018 5 6 7 Dr Trish Groves 8 9 Editor in Chief, BMJ Open 10 11 BMJ Open Editorial Office, BMA House 12 13 Tavistock Square, London, WC1H 9JR, UK 14 15 16 For peer review only 17 18 19 Dear Dr Groves, 20 21 We would like to submit the attached manuscript “Can we IMPROVE cardiovascular 22 23 outcomes through phosphate lowering in CKD? - Rationale for the IMpact of Phosphate 24 25 Reduction On Vascular End-points in Chronic Kidney Disease (IMPROVE-CKD) study” for 26 27 publication in BMJ Open. We believe this is an important manuscript because of the paucity 28 29 of clinical trials assessing the benefits of treating hyperphosphatemia in patients with chronic 30
31 http://bmjopen.bmj.com/ 32 kidney disease (CKD), despite this management being common clinical practice based on 33 34 numerous experimental and observational studies suggesting phosphate imbalance as a 35 36 cardiovascular risk factor. This manuscript outlines the rationale and protocol for an 37 38 international, multi centre, placebo controlled randomized trial in pre dialysis CKD patients 39 on September 30, 2021 by guest. Protected copyright. 40 currently being conducted and this paper has not been submitted for publication elsewhere. 41 42 43 44 45 Yours sincerely, 46 47 48 49 50 Associate Professor Nigel Toussaint 51 52 Department of Nephrology, The Royal Melbourne Hospital 53 54 Grattan Street, Parkville, Victoria 3052, Australia. 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 2 of 40
2 1 2 3 4 Title page 5 6 7 8 9 10 Can we IMPROVE cardiovascular outcomes through phosphate lowering 11 12 13 in CKD? - Rationale for the IMpact of Phosphate Reduction On Vascular 14 15 End-points in Chronic Kidney Disease (IMPROVE-CKD) study 16 For peer review only 17 18 19 20 21 Nicole LIOUFAS*1,2, Nigel D TOUSSAINT*1,2, Eugenia PEDAGOGOS2,3, Grahame J 22 23 ELDER4,5, Sunil V BADVE6, Elaine M PASCOE7,8, Andrea VALKS7,8, Carmel M 24 25 HAWLEY7,8,9, on behalf of the IMPROVE-CKD Writing Committee. 26 27 28 1Department of Nephrology, The Royal Melbourne Hospital, Parkville, Australia, 29 30 2Department of Medicine (RMH), University of Melbourne, Parkville, Australia, 3Epworth 31 http://bmjopen.bmj.com/ 32 4 33 HealthCare, Melbourne, Australia, Department of Renal Medicine, Westmead Hospital,
34 5 35 Westmead, Australia, Osteoporosis and Bone Biology Division, Garvan Institute of Medical 36 6 37 Research, Darlinghurst, Australia, Department of Nephrology, St. George Hospital, Sydney, 38
39 Australia, 7Faculty of Medicine, University of Queensland, Woolloongabba, Australia, on September 30, 2021 by guest. Protected copyright. 40 41 8Australasian Kidney Trials Network, Brisbane, Australia, 9Department of Nephrology, 42 43 Princess Alexandra Hospital, Woolloongabba, Australia. 44 45 46 * Co primary authors 47 48 49 Running head: IMPROVE CKD study 50 51 52 Word count: Abstract 287 Text 3584 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 3 of 40 BMJ Open
3 1 2 3 4 Correspondence: Associate Professor Nigel Toussaint 5 6 Department of Nephrology, The Royal Melbourne Hospital, 7 8 Grattan Street, Parkville, Victoria 3052, Australia. 9 10 E mail: [email protected] 11 12
13 14 15 Keywords: arterial compliance, cardiovascular disease, chronic kidney disease, chronic 16 For peer review only 17 kidney disease mineral and bone disorder (CKD MBD), phosphate, vascular calcification 18 19 20 21 22 23 24 25 26 27 28 29 30 31 http://bmjopen.bmj.com/ 32 33 34 35 36 37 38
39 on September 30, 2021 by guest. Protected copyright. 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 4 of 40
4 1 2 3 4 IMPROVE-CKD investigators: 5 6 7 Nigel D Toussaint, The Royal Melbourne Hospital, Parkville, Victoria, Australia 8 Eugenia Pedagogos, Epworth Healthcare, Melbourne, Victoria, Australia 9 10 Nicole Lioufas, The Royal Melbourne Hospital, Parkville, Victoria, Australia 11 Carmel M Hawley, Princess Alexandra Hospital, Brisbane, Queensland, Australia 12 Grahame J Elder, Westmead Hospital, Westmead, New South Wales, Australia 13 14 Elaine M Pascoe, Australasian Kidney Trials Network, Brisbane, Australia 15 Andrea Valks, Australasian Kidney Trials Network, Brisbane, Australia 16 For peer review only 17 Sunil V Badve, St. George Hospital, Sydney, New South Wales, Australia 18 Geoffrey A Block, Colorado Kidney Care, Denver, United States 19 20 Neil C Boudville, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia; and 21 University of Western Australia, Perth, Western Australia, Australia 22 23 Katrina Campbell, Princess Alexandra Hospital, Brisbane, Queensland, Australia 24 James D Cameron, Monash Medical Centre, Clayton, Victoria, Australia 25 26 Sylvia Chen, Epworth Healthcare, Melbourne, Victoria, Australia 27 Randall J Faull, Royal Adelaide Hospital, Adelaide, South Australia, Australia 28 29 Stephen G Holt, The Royal Melbourne Hospital, Parkville, Victoria, Australia 30 Lai S Hooi, Sultanah Aminah Hospital, Johor Bahru, Malaysia 31 http://bmjopen.bmj.com/ 32 Dana Jackson, Monash Medical Centre, Clayton, Victoria, Australia 33 Meg J Jardine, Concord Hospital, Sydney, New South Wales, Australia 34 35 David W Johnson, Princess Alexandra Hospital, Brisbane, Queensland, Australia; and 36 University of Queensland, Brisbane, Queensland, Australia 37 38 Peter G Kerr, Monash Medical Centre, Clayton, Victoria, Australia 39 Kenneth K Lau, Monash Medical Centre, Clayton, Victoria, Australia on September 30, 2021 by guest. Protected copyright. 40 41 Alicia Morrish, Australasian Kidney Trials Network, Brisbane, Australia 42 Vlado Perkovic, The George Institute, Sydney, New South Wales, Australia 43 44 Kevan R Polkinghorne, Monash Medical Centre, Clayton, Victoria, Australia 45 Carol A Pollock, Royal North Shore Hospital, Sydney, New South Wales, Australia 46 47 Donna Reidlinger, Australasian Kidney Trials Network, Brisbane, Australia 48 Laura Robison, Australasian Kidney Trials Network, Brisbane, Australia 49 50 Edward R Smith, The Royal Melbourne Hospital, Parkville, Victoria, Australia 51 Robert J Walker, Dunedin Hospital, Dunedin, New Zealand 52 53 Angela Yee Moon Wang, University of Hong Kong, Queen Mary Hospital, Hong Kong 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 5 of 40 BMJ Open
5 1 2 3 4 Abstract 5 6 Introduction: Further understanding abnormalities of bone and mineral metabolism in 7 8 9 chronic kidney disease (CKD) should lead to strategies to reduce cardiovascular risk in the 10 11 CKD population; however, there is a paucity of large randomized controlled clinical trials to 12 13 guide appropriate management. Positive associations between serum phosphate and fibroblast 14 15 growth factor 23 (FGF 23) and cardiovascular morbidity and mortality in both the general 16 For peer review only 17 and CKD populations have resulted in clinical guidelines recommending management of 18 19 hyperphosphatemia in patients with CKD, targeting normal serum phosphate levels, although 20 21 very few studies have addressed clinical outcomes using interventions to improve phosphate 22 23 24 control in a randomized and placebo controlled fashion. Early preventive measures to reduce 25 26 the development and progression of vascular calcification, left ventricular hypertrophy, and 27 28 arterial stiffness are crucial in patients with CKD. 29 30 Methods and Analysis: We outline the rationale and protocol for an international, multi 31 http://bmjopen.bmj.com/ 32 centre, randomized parallel group trial assessing the impact of the non calcium based 33 34 phosphate binder, lanthanum carbonate, compared to placebo on surrogate markers of 35 36 37 cardiovascular disease in a pre dialysis CKD population – the IMPROVE CKD study. The 38
39 primary objective of the IMPROVE CKD study is to determine if use of lanthanum carbonate on September 30, 2021 by guest. Protected copyright. 40 41 reduces the burden of cardiovascular disease in patients with CKD stages 3b and 4 when 42 43 compared to placebo. The primary end point of the study is change in arterial compliance 44 45 measured by pulse wave velocity over a 96 week period. Secondary outcomes include change 46 47 in aortic calcification and biochemical parameters of serum phosphate, parathyroid hormone 48 49 50 and FGF 23 levels. 51 52 Ethics and Dissemination: Ethical approval for the IMPROVE CKD trial was obtained by 53 54 each local Institutional Ethics Committee for all 17 participating sites in Australia, New 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 6 of 40
6 1 2 3 4 Zealand and Malaysia prior to study commencement. Results of this clinical trial will be 5 6 published in peer reviewed journals and presented at conferences. 7 8 9 10 IMPROVE-CKD registration number ACTRN12610000650099 11 12 13 14 15 Strengths and limitations of this study 16 For peer review only 17 18 19 • To the best of our knowledge, this international clinical trial will be the largest cohort 20 21 and longest in study duration for a randomized, placebo controlled trial assessing 22 23 phosphate binders in a pre dialysis chronic kidney disease (CKD) population. 24 25 26 • This study assesses potential effects of phosphate lowering on arterial compliance, 27 28 aortic calcification and left ventricular mass; and study findings will provide support 29 30 for the current hypothesis that phosphate binders and control of hyperphosphatemia
31 http://bmjopen.bmj.com/ 32 may mitigate adverse cardiovascular outcomes in patients with CKD. 33 34 35 • This study uses lanthanum carbonate, a non calcium based phosphate binder, which 36 37 allows for more accurate assessment of the effect of phosphate binding strategies on 38
39 vascular calcification (without the complication of an exogenous calcium load) and on September 30, 2021 by guest. Protected copyright. 40 41 may provide evidence to help inform guidelines that currently lack strong evidence 42 43 for phosphate control in pre dialysis CKD. 44 45 46 • In addition, the IMPROVE CKD study will provide valuable information regarding 47 48 the relationship between phosphate, FGF 23, and arterial compliance and 49 50 calcification in patients with CKD. 51 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 7 of 40 BMJ Open
7 1 2 3 4 • Limitations to this trial may include potential difficulty in recruitment of a large CKD 5 6 population to a study assessing the use of thrice daily phosphate binding agents, and 7 8 possible lack of adherence to study medication over a 96 week period. 9 10 11 12 13 14 15 16 For peer review only 17 18 19 20 21 22 23 24 25 26 27 28 29 30
31 http://bmjopen.bmj.com/ 32 33 34 35 36 37 38
39 on September 30, 2021 by guest. Protected copyright. 40 41 42 43 44
45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 8 of 40
8 1 2 3 4 ‘Chronic Kidney Disease Mineral Bone Disorder’ (CKD MBD) has been accepted 5 6 terminology in nephrology research and clinical practice for more than a decade. This clinical 7 8 syndrome encompasses intimately related abnormalities of mineral homeostasis, bone 9 10 turnover and mineralization, and vascular and soft tissue calcification, which are almost 11 12 universal in patients with advanced chronic kidney disease (CKD). CKD MBD is a complex 13 14 15 and evolving area for which international clinical guidelines have been published to provide 16 For peer review only 17 suggestions and recommendations on management (1). Just as importantly, these guidelines 18 19 highlight the paucity of clinical studies supporting suggested biochemical targets, and the 20 21 lack of evidence based treatment strategies aimed at reducing the risks of fracture, 22 23 cardiovascular disease and mortality or improving quality of life for individuals with CKD. 24 25 26 27 28 29 Patients with CKD have significantly increased risks of cardiovascular disease and all cause 30
31 mortality compared to the general population (2), and traditional and CKD specific risk http://bmjopen.bmj.com/ 32 33 factors contribute to this risk (3). Abnormalities of bone and mineral metabolism, and in 34 35 particular abnormal values of serum phosphate, calcium, parathyroid hormone (PTH) and 36 37 fibroblast growth factor 23 (FGF 23), are considered important however few strong 38
39 on September 30, 2021 by guest. Protected copyright. 40 recommendations for treatment of these values exist beyond normalising serum phosphate 41 42 and lowering PTH to an indeterminate target (1). Minimizing exogenous calcium through 43 44 reducing exposure to calcium based phosphate binders within the CKD population has also 45 46 been suggested to be beneficial, citing meta analyses showing mortality benefits of non 47 48 calcium containing phosphate binders over calcium based binders (4, 5), but placebo 49 50 controlled studies are lacking. 51 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 9 of 40 BMJ Open
9 1 2 3 4 Whilst observational studies show associations between higher serum phosphate levels and 5 6 worse clinical outcomes, causality has never been demonstrated. Serum phosphate provides a 7 8 poor measure of overall phosphate balance or the risk of soft tissue calcification in patients 9 10 with CKD, and benefits of phosphate lowering are yet to be demonstrated. Whether a target 11 12 level of serum phosphate will assist in attaining improved outcomes remains controversial 13 14 15 and no randomized controlled trial (RCT) to date has proved that lowering extracellular 16 For peer review only 17 phosphate improves clinical outcomes. The IMPROVE CKD (IMpact of Phosphate 18 19 Reduction On Vascular End points in Chronic Kidney Disease) study is a placebo controlled 20 21 RCT assessing the potential effects of lanthanum carbonate, a non calcium based phosphate 22 23 binder, on surrogate markers of cardiovascular disease in patients with CKD. Here, we 24 25 discuss the rationale and study design of this important trial. 26 27 28 29 30 31 Rationale for a clinical trial http://bmjopen.bmj.com/ 32 33 34 Epidemiological studies in the general population and in patients with CKD have consistently 35 36 shown that serum phosphate levels within and above the upper normal range are 37 38 independently and positively correlated with all cause mortality (6). In patients with CKD, 39 on September 30, 2021 by guest. Protected copyright. 40 cardiovascular mortality, arterial stiffness and progression of renal impairment have also been 41 42 correlated with higher serum phosphate (7, 8). Positive phosphate balance is known to 43 44 45 contribute to rising PTH and FGF 23 values, which in turn, have also been associated with 46 47 adverse clinical outcomes (9, 10). Thus, it is biologically plausible that therapeutic strategies 48 49 aimed at reducing phosphate balance and serum phosphate values in patients with CKD 50 51 might be beneficial. Dietary phosphate absorption is one modifiable determinant of phosphate 52 53 balance and pilot studies that have evaluated phosphate binders, low phosphate diet, or 54 55 nicotinamide (which inhibits intestinal sodium dependent phosphate co transport) in patients 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 10 of 40
10 1 2 3 4 with CKD have shown a reduction of dietary phosphate absorption, serum phosphate and 5 6 FGF 23 levels (11). However, evidence for the benefit of such strategies on surrogates for 7 8 cardiovascular disease or for CKD progression remains elusive. 9 10 11 12 13 14 Abnormal mineral metabolism, with alterations in the regulation of calcium, phosphate and 15 16 FGF 23, is alsoFor associated peer with the development review of vascular only calcification (12). Although 17 18 mechanisms leading to vascular calcification are incompletely understood, hypotheses 19 20 include a maladaptive repair response to vascular and endothelial damage (13), and 21 22 enhancement of concentration dependent calcium phosphate precipitation and extracellular 23 24 25 matrix deposition due to elevated phosphate levels. Studies also report coronary artery 26 27 calcification associated with elevated FGF 23 values independent of serum phosphate (10, 28 29 14), although this association is not a consistent finding (15). In addition to abnormalities of 30
31 mineral metabolism, exogenous calcium has been associated with the development and http://bmjopen.bmj.com/ 32 33 progression of vascular calcification in patients with CKD. A meta analysis of phosphate 34 35 binders by Jamal et al, analysing 14 RCTs, reported a reduction in mortality associated with 36 37 the use of non calcium containing phosphate binders (4). A more recent meta analysis of 25 38
39 on September 30, 2021 by guest. Protected copyright. 40 eligible studies showed a reduction in all cause mortality with sevelamer versus calcium 41 42 based binders (5). This difference is potentially related to a positive calcium balance in 43 44 patients prescribed calcium based phosphate binders leading to increasing vascular 45 46 calcification. Another meta analysis reviewed the individual contribution of available non 47 48 calcium based phosphate binders, and reported that current data are more robust for 49 50 sevelamer than for lanthanum or iron based binders (16). 51 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 11 of 40 BMJ Open
11 1 2 3 4 The recently updated Kidney Disease Improving Global Outcomes (KDIGO) CKD MBD 5 6 Guidelines (17) highlighted the lack of trial data demonstrating that lowering serum 7 8 phosphate improved patient centred outcomes. In fact, the evidence for any phosphate 9 10 lowering intervention is only based on epidemiological studies and biological plausibility. 11 12 Although several recent historical cohort analyses (DOPPS, ArMORR and COSMOS) 13 14 15 suggested that the prescription of phosphate binders to dialysis patients improved survival 16 For peer review only 17 (18 20), these reports were not included in the evidence review for the updated KDIGO 18 19 Guidelines. However, a recent RCT comparing calcium and non calcium based phosphate 20 21 binders with placebo in 148 patients with CKD stages 3 4 (21) was included in the guideline 22 23 update review and reported a minimal reduction of serum phosphate in the active treatment 24 25 groups, no overall effect on FGF 23 and increases in coronary artery calcification for the 26 27 28 combined phosphate binder groups (predominantly associated with the calcium based binder 29 30 arm).
31 http://bmjopen.bmj.com/ 32 33 34 35 Similarly, two placebo controlled RCTs of phosphate lowering in pre dialysis CKD have 36 37 also failed to support the benefit of phosphate lowering in this population (Table 1). Chue et 38
39 on September 30, 2021 by guest. Protected copyright. 40 al. found no significant differences between sevelamer and placebo with regard to left 41 42 ventricular mass, systolic and diastolic function, or pulse wave velocity (PWV) in 109 43 44 patients with CKD after 40 weeks, although only 56% of subjects took ≥80% of the 45 46 prescribed therapy (22). In the adherent subgroup, treatment with sevelamer was associated 47 48 with lower urinary excretion of phosphate and serum FGF 23, although binder use was not 49 50 associated with cardiovascular outcomes of interest such as left ventricular hypertrophy or 51 52 53 arterial compliance. In a smaller study of 38 CKD patients, Seifert et al. reported no 54 55 differences between lanthanum or placebo over 12 months with respect to serum or urinary 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 12 of 40
12 1 2 3 4 phosphate, or surrogate cardiovascular markers of PWV, carotid artery intima media 5 6 thickness or vascular calcification (23). These results question the efficacy and safety of 7 8 phosphate binders in this population and the updated KDIGO guidelines have amended a 9 10 previous recommendation statement to maintain serum phosphate in the normal range for 11 12 patients with CKD stages 3 5 to now suggest that treatment should focus on patients with 13 14 15 overt hyperphosphatemia, although this recommendation is still based on weak clinical 16 For peer review only 17 evidence. 18 19 20 21 22 Currently there are two relevant RCTs in progress (Table 1). The COMBINE (CKD Optimal 23 24 25 Management With BInders and NicotinamidE) study assesses the effects of lowering serum 26 27 phosphate and FGF 23 levels in patients with CKD stages 3 4 (11). This study aims to recruit 28 29 200 participants and evaluate the use of nicotinamide and lanthanum carbonate in a double 30
31 blind, placebo controlled trial over 12 months. The primary aim of COMBINE is the safety http://bmjopen.bmj.com/ 32 33 and biochemical efficacy of these phosphate lowering agents, although assessments of 34 35 circulating biomarkers of bone and mineral metabolism and magnetic resonance imaging 36 37 (MRI) of intermediate measures of cardiovascular disease will also be measured. Enrolment 38
39 on September 30, 2021 by guest. Protected copyright. 40 for this RCT began in 2015 with results expected in 2018. We have also commenced a large 41 42 multi centre RCT, the IMPROVE CKD study, to investigate the role of phosphate binders in 43 44 early stages of CKD. This trial, conducted over a longer period and with a larger cohort, aims 45 46 to assess potential effects of phosphate lowering on arterial compliance, vascular calcification 47 48 and left ventricular mass. 49 50 51 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 13 of 40 BMJ Open
13 1 2 3 4 Table 1. Placebo controlled RCTs of phosphate lowering in patients with CKD stage 3 5 not 5 6 on dialysis 7 8 9 Study Population Intervention Finding 10 11 Block et al 148 patients Lanthanum Reduced urinary phosphate and 12 13 (PNT)(21) CKD3 4 carbonate, serum phosphate; 14 15 sevelamer Promotion of vascular calcification 16 For peer review only 17 carbonate, with binders; 18 19 20 calcium acetate No difference in PWV 21 22 Chue et al 120 patients Sevelamer Lower urinary phosphate and 23 24 (CRIB CKD3 non carbonate vs FGF 23 (later in compliant 25 26 PHOS)(22) diabetic placebo patients) 27 28 Seifert et al(23) 38 patients Lanthanum vs No differences in serum/urine 29 30 CKD3 placebo phosphate, PWV, carotid IMT, 31 http://bmjopen.bmj.com/ 32 33 vascular calcification 34 35 Isakova et al Aimed Lanthanum vs Ongoing 36 37 (COMBINE)(11) recruitment of lanthanum + 38 39 200 patients nicotinamide vs on September 30, 2021 by guest. Protected copyright. 40 41 CKD3 4 nicotinamide vs 42 43 placebo 44 45 46 IMPROVE CKD Aimed Lanthanum vs Ongoing 47 48 recruitment of placebo 49 50 488 patients 51 52 with CKD3b 4 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 14 of 40
14 1 2 3 4 Abbreviations: IMT, intimal medial thickness; PWV, pulse wave velocity; PNT, Phosphate 5 Normalisation Trial; CRIB PHOS, Chronic Renal Impairment in Birmingham – Phosphate study; 6 7 COMBINE, CKD Optimal Management With BInders and NicotinamidE study; IMPROVE CKD, 8 Impact of Phosphate Reduction On Vascular End Points in CKD 9 10 11 12 13 14 15 16 For peer review only 17 Overview of the IMPROVE-CKD Study 18 19 20 Study aims 21 22 23 The primary objective of the IMPROVE CKD study is to determine if use of the non 24 25 calcium based phosphate binder lanthanum carbonate reduces the burden of cardiovascular 26 27 disease in patients with CKD stages 3b and 4 when compared to placebo. The primary end 28 29 point of the study is change in arterial compliance measured by PWV over a 96 week period. 30 31 Secondary outcomes include change in aortic calcification and biochemical parameters of http://bmjopen.bmj.com/ 32 33 serum phosphate, PTH and FGF 23 levels. 34 35 36 37 38
39 Study design and setting on September 30, 2021 by guest. Protected copyright. 40 41 42 The IMPROVE CKD study is an investigator led, prospective, double blind, randomized 43 44 placebo controlled parallel group trial. Figure 1 demonstrates the overall study design. 45 46 Ethical approval for the IMPROVE CKD trial was obtained by each local Institutional Ethics 47 48 Committee (IEC) for each participating site prior to study commencement. This study is 49 50 being conducted in accordance with the Declaration of Helsinki, the National Health and 51 52 53 Medical Research Committee (NHMRC) statement on Human Experimentation, Joint 54 55 NHMRC/AVCC statement and Guidelines on Practical Research, applicable ICH guidelines 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 15 of 40 BMJ Open
15 1 2 3 4 and the Therapeutic Goods Administration (TGA). The trial is registered with the Australia 5 6 and New Zealand Clinical Trial Register (ACTRN12610000650099). 7 8 9 10 11 12 Patients and public involvement 13 14 Patients and the public were not involved in the development of this study protocol; however 15 16 patients are involvedFor in thepeer recruitment review to and conduct of onlythe study. The IMPROVE CKD 17 18 study includes patients from 17 nephrology sites in Australia, New Zealand and Malaysia 19 20 with CKD stage 3b and stage 4, aged over 18 years old, and who have a serum phosphate 21 22 level over 1.00 mmol/L (3.10 mg/dL) on at least one occasion in the 6 months prior to 23 24 25 randomization (Table 2). Patient recruitment commenced in 2012, with a plan to enrol 488 26 27 participants for a 96 week study period. During the recruitment phase of the study, changes 28 29 were made to the inclusion and exclusion criteria in order to improve feasibility and 30
31 generalizability of the trial. The changes and rationale are documented in Table 3. http://bmjopen.bmj.com/ 32 33 34 35 36 37 38
39 on September 30, 2021 by guest. Protected copyright. 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 16 of 40
16 1 2 3 4 Table 2. Inclusion and Exclusion Criteria for the IMPROVE CKD study 5 6 7 Inclusion criteria 8 2 9 1. Patients with CKD stages 3b and 4 (eGFR between 15 and 45 ml/min/1.73m )* 10 11 2. Serum phosphate > 1.00 mmol/L (3.10 mg/dL) on at least one occasion in the 12 13 previous 6 months 14 15 3. 18 years or over 16 For peer review only 17 4. Able to give informed consent 18 19 20 Exclusion criteria 21 22 1. Patients with a history of psychological illness or condition which interferes with 23 24 their ability to understand or comply with the requirements of the study 25 26 2. Renal transplantation 27 28 3. Recent (within 1 month) hospitalization or cardiovascular event 29 30 4. Pregnancy or breast feeding 31 http://bmjopen.bmj.com/ 32 33 5. Medical conditions that impact on phosphate metabolism (apart from CKD), e.g. 34 35 primary hyperparathyroidism or hypoparathyroidism; previous subtotal 36 37 parathyroidectomy; gastrointestinal malabsorption disorders such as Crohn’s 38 39 disease, ulcerative colitis, coeliac disease or severe liver dysfunction on September 30, 2021 by guest. Protected copyright. 40 41 6. Malnutrition, defined as serum albumin < 30 g/L 42 43 7. Serum phosphate ≤ 0.8 mmol/L (2.48 mg/dL) at screening 44 45 46 8. Atrial fibrillation as documented on ECG performed at screening 47 48 9. Inability to perform PWV 49 50 *eGFR determined using the CKD Epidemiology Collaboration (CKD EPI) equation 51 52 Abbreviations: CKD, chronic kidney disease; ECG, electrocardiogram; eGFR, estimated glomerular filtration 53 54 rate 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from 17 17
44 46 As the trial progressed, a small small a progressed, trial the As Exclusion criterion was added asadded criterion was Exclusion Pulse wave velocity; Changes between Changes between Pulse velocity; wave measure. a PWV to obtain inability Protocol versions 2.0 to 3.0 to 2.0 Protocol versions on whom a PWV reading could not be could not be PWV reading a on whom as added therefore This was obtained. order to in criterion exclusion an is power of the study not the ensure individuals by including compromised at unattainable whose is PWV recognised is increasingly screening. It operators, for even experienced that of the small a percentage there is on documented been This has obtained. studies. other percentage of the population was noted was of the percentage population cannot be PWV on population whom
serum phosphate serum phosphate
http://bmjopen.bmj.com/ BMJ Open
The The window for results to screen eligible patients was patients eligible results to screen the within be changed initially to of 1.2mmol/L. levels and above below to improve was made Thischange the by study broadening recruitment to review continued Trial log screening a was inclusion criterion this show that for eligibility major to patient barrier level was and the the therefore study change reduced This to 1.0mmol/L. affect the adversely to wasthought not the although because study outcomes Serum phosphate level; Changes Changes level; Serum phosphate for was initially criterion Inclusion >1.2mmol/L level serum phosphate at screening, but was (3.72mg/dL) at one least on >1.2mmol/L changed to months. 6 occasion the previous over then level was The serum phosphate from reduced subsequently to >1.0mmol/L >1.2mmol/L on occasion one least (3.10mg/dL) at 6 over months. the previous 3.0 previous 6 months due to fluctuations fluctuations to due previous 6 months participants. suitable population of between Protocol versions 1.0 to 2.0 to to 2.0 1.0 between versions Protocol
on September 30, 2021 by guest. Protected copyright.
For peer review only For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml The initial introduction of these criteria criteria these of The initial introduction of CKD proportion wasto the increase risk at greater were 3b/4 who subjects as as well disease of cardiovascular of renal increased progression of risk logs of screening Review impairment. that albuminuria/proteinuria showed criteria, exclusion commonest were the as they were therefore removed these a posed essential, considered were not to recruitment, impediment significant was recruitment for and the population increased at already deemed Albuminuria/Proteinuria; Changes Changes Albuminuria/Proteinuria; were urine criteria Initial inclusion (ACR) ratio albumin/creatinine protein/creatinine or >10mg/mmol (PCR) ratio >15mg/mmol. subsequently criteria These were removed. between Protocol versions 1.0 to to 2.0 1.0 Protocol between versions
Rationale for Rationale change Protocol Protocol amendment Issue and Issue and version of protocol Table 3. Protocol amendments for the IMPROVE CKD study for the IMPROVE CKD amendments Table Protocol 3.
Page 17 of 40 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 18 of 40 18 18 http://bmjopen.bmj.com/ BMJ Open study is using a phosphate binder as an binder study phosphate using is a purpose of primary the intervention, of the attenuation the study is cardiovascular outcomes. wasadded level as A phosphate lower that ensure to ancriterion exclusion study where the into are not included may reduction further phosphate health. their adversely affect patients with very low phosphate levels levels low phosphate patients with very on September 30, 2021 by guest. Protected copyright.
For peer review only For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml
43 cardiovascular risk regardless of of risk regardless cardiovascular this Also, for albuminuria/proteinuria. is (PWV) study, velocity wave pulse and end point surrogate the primary which one there is publication only to PWV, links albuminuria/proteinuria considered not sois association this significant.
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19 1 2 3 4 Experimental intervention 5 6 7 Lanthanum carbonate (Fosrenol) is a commercial product of Shire Pharmaceuticals for the 8 9 treatment of hyperphosphatemia (24). Upon ingestion, lanthanum ions are released from the 10 11 carbonate as a result of gastric acid secretion in the upper gastrointestinal tract and bind to 12 13 dietary phosphate. The compound lanthanum phosphate is insoluble and lanthanum carbonate 14 15 has been shown to effectively reduce the absorption of dietary phosphate in the CKD 16 For peer review only 17 population. In comparison to calcium based phosphate binders, lanthanum carbonate has 18 19 20 additional benefits of reduced incident hypercalcemia (25). Lanthanum has been studied in 21 22 both pre dialysis and dialysis patients, with significant reduction in serum phosphate in both 23 24 patient groups. 25 26 27 28 29 30 Treatment randomisation
31 http://bmjopen.bmj.com/ 32 Participants are randomized 1:1 to two arms involving lanthanum carbonate 500mg three 33 34 times daily with meals or matching placebo three times daily with meals for 96 weeks. Study 35 36 37 medication is up titrated to a total dose of six tablets daily (3000mg/day lanthanum 38
39 carbonate) if serum phosphate remains persistently greater than 1.60 mmol/L (4.95 mg/dL). on September 30, 2021 by guest. Protected copyright. 40 41 Randomization is stratified for age, presence of diabetes, study site and CKD stage and 42 43 implemented via web based access to a central electronic randomization system provided by 44 45 The George Institute in Sydney, Australia. 46 47 48 49 50 51 Study procedures 52 53 54 Patients who meet the eligibility criteria and provide written informed consent undergo a 55 56 baseline visit. A site screening log records the number of participants screened who are 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 20 of 40
20 1 2 3 4 potentially eligible to participate and the reasons for ineligibility and for non participation if 5 6 eligible. Potentially eligible participants already receiving a phosphate binder at screening 7 8 undergo a 2 week washout period before attending the baseline visit. Tables 4 and 5 outline 9 10 the study schedule visits and laboratory outcome measures for the 96 week trial. 11 12 13 14 15 16 The IMPROVE CKDFor study peer is being overseen review by the Trial only Steering Committee (TSC) and 17 18 centrally coordinated by the Australasian Kidney Trials Network (AKTN) (Appendix). The 19 20 safety of participants is overseen by an independent Data Safety Monitoring Board 21 22 (Appendix). Participants, investigators, the AKTN coordinating centre staff and outcome 23 24 25 assessors are all blinded to the treatment assignment in the IMPROVE CKD study. 26 27 28 29 30
31 http://bmjopen.bmj.com/ 32 33 34
35 36 37 38 39 on September 30, 2021 by guest. Protected copyright. 40 41 42 43
44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from
END END week 96 Month 24 21 21
Visit 7 Visit 7 week 84 week Month 21Month
Visit 6 Visit 6 week 72 week Month 18Month
Visit Visit 5 week 60week baseline Month 15Month
Visit Visit 4 Weeks postWeeks week 48week Month 12Month
X X X X X X X Visit 3 3 Visit week 36week Month 9Month
(Study ±14window (Study visit is days fromdue date of baseline) X X X X X X X X X Visit 2 Visit week 24 Month 6Month
X X Visit 1 Visit 1 Week Week 12 Month 3Month http://bmjopen.bmj.com/ BMJ Open X X X X X X X X X Baseline
X X X
X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X on September 30, 2021 by guest. Protected copyright. Screening/ Screening/ Randomisation For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml
For peer review only
Visits
Dietitian assisted Dietitian food record^ (for participating sites) Adverse Events recordedAdverse Events (SAEs ADRs)and Medication returnedMedication Medication Medication dispensed Cardiac Cardiac * MRI (for participating sites) Pulse Wave Velocity and Pulse Wave Velocity Augmentation Index CT scan CT – multi slice, non contrast * Concomitant Medications Physical ExaminationPhysical Demographics and Demographics History Medical Electrocardiogram (ECG)Electrocardiogram Participant randomisedParticipant Informed Informed Consent Visit Assessments Visit
* if* participantsthe from after study months12 withdraw and prior to 24 months will beto they do requested a CT ‘close out’ and MRI scan. scans additional will sites diastolic also to Some MRI investigate perform dysfunction study the of component dietary the in enrolled participants ^ for Abbreviations: CT, computed tomography; MRI, resonancemagnetic imaging, ADRs, adverse drug reactions; serious SAEs, eventsadverse Table 4. Schedule of visits for the IMPROVE CKD study study IMPROVE CKD the for of Table visits Schedule 4.
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Page 22 of 40 END END Month 24Month 22 22
84 96 week Visit Visit 7 Month 21Month
Visit Visit 6 Month 18Month
Visit Visit 5 baseline Month 15Month
Weeks postWeeks Visit 4 Visit 4 Month 12
Visit 3 Visit 3 Month 9 Month (Laboratory (Laboratory test is ±14window from days visit date)
Visit Visit 2 Month 6 Month
Visit 1 Visit 1
http://bmjopen.bmj.com/ Week Week 12 24 week week 36 week 48 60 week 72 week week Month 3 BMJ Open
Baseline
X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X on September 30, 2021 by guest. Protected copyright. Screening/ Screening/ Randomisation
For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml For peer review only Phosphate:creatinine Vitamin D Vitamin binding protein Calcification inhibitorsCalcification (OPG, MGP, fetuin A) Asymmetrical Asymmetrical argininedimethyl (ADMA) Fibroblast Fibroblast growth factor 23 (FGF 23) Centrally Tested Laboratory Assessments 24 Hour UrineHour collection24 excretion – timed Spot urine (ACR,Spot PCR and ratio) Vitamin D(25 D) Vitamin Iron studiesIron Other Other Liver Function Tests Intact Parathyroid Intact Hormone(iPTH) HbA1c *HbA1c Fasting GlucoseFasting Fasting ProfileFasting Serum Lipid C reactive ProteinC reactive (CRP) Biochemistry, Renaland Biochemistry, Liver Function Tests Full Blood CountFull Locally Tested LaboratoryLocally Tested Assessments Visits
diabetes patients with in performed Only * ACR,Abbreviations: albumin:creatinine PCR, ratio; protein:creatinineratio; MGP, matrix protein; OPG, Gla osteoprotegerin Table 5. Laboratory outcome measures in the IMPROVE CKD study IMPROVE CKD in the measures Table outcome Laboratory 5.
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23 1 2 3 4 Primary outcome 5 6 7 The primary outcome of the IMPROVE CKD study is change in large arterial compliance (as 8 9 measured by carotid femoral PWV) at 96 weeks after randomization to lanthanum carbonate 10 11 or placebo. Hyperphosphatemia has been associated with reduced arterial compliance and 12 13 multiple studies have reported a positive relationship between serum phosphate and PWV (8, 14 15 26). PWV has been used to measure arterial compliance and is considered to be a valid 16 For peer review only 17 surrogate for cardiovascular morbidity and mortality (27, 28). PWV also correlates with CKD 18 19 20 stage and increases as CKD progresses (29, 30). In the IMPROVE CKD study, arterial 21 22 compliance is being measured using a SphygmoCor device (AtCor, PWV Inc., Westmead, 23 24 Sydney, Australia) with determination of carotid femoral PWV. Carotid femoral PWV 25 26 measures the interval between pulse waves at the carotid and femoral arteries, with higher 27 28 values representing stiffer vessels. Mean inter observer and day to day reproducibilities of 29 30 PWV measurements have been reported in studies of patients with CKD to be acceptable, 31 http://bmjopen.bmj.com/ 32 33 with differences of 0.3 +/ 3.2 m/s and 0.7 +/ 1.9 m/s in some studies (31). Pulse wave 34 35 analysis is also being measured using augmentation index (AI) by the SphygmoCor device as 36 37 an additional outcome. AI represents the difference between early and late systolic peaks of 38
39 the systolic pulse wave contour, divided by pulse pressure (%). on September 30, 2021 by guest. Protected copyright. 40 41 42 43 44 45 Secondary Outcomes 46 47 Vascular calcification 48 49 Abdominal aortic calcification is being determined using computed tomography (CT) at 50 51 baseline and 96 weeks in the IMPROVE CKD study. If patients exit the study after 12 52 53 months, they will be invited to have an early exit CT scan. Aortic calcification is estimated to 54 55 be present in approximately 60% of patients with CKD stages 4 and 5, and increases in those 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 24 of 40
24 1 2 3 4 on dialysis, with progressive disease related to dialysis vintage (32). Aortic calcification is 5 6 related to the presence of other vascular disease, as well as to serum phosphate and PTH 7 8 levels. There is an association of aortic calcification and arterial compliance, with 9 10 correlations between calcium scoring via CT and PWV (26). 11 12
13 14 15 Left ventricular hypertrophy 16 For peer review only 17 PWV has been associated with increased left ventricular mass and the development of 18 19 diastolic dysfunction in hypertensive patients (33). However, left ventricular mass has also 20 21 been associated with the development of hyperphosphatemia independent of PWV (7). In the 22 23 IMPROVE CKD study, cardiac magnetic resonance imaging (MRI), the gold standard to 24 25 evaluate the development of left ventricular hypertrophy, is being used to measure left 26 27 28 ventricular mass on a sub cohort of participants at baseline and 96 weeks. If a patient exits 29 30 the study after 12 months, they will be invited to have an exit MRI.
31 http://bmjopen.bmj.com/ 32 33 34 Biochemical parameters 35 36 Serum phosphate, calcium and PTH are being assessed throughout the 96 week study period 37 38 and FGF 23 is being measured 6 monthly using intact and c terminal FGF 23 assays. 39 on September 30, 2021 by guest. Protected copyright. 40 41 Changes in urinary phosphate excretion are also being evaluated using 24 hour urine 42 43 collections. Standard biochemical measurements are being performed in hospital laboratories 44 45 with appropriate regulatory accreditation to monitor for adverse reactions. 46 47 48 49 50 Dietary phosphate 51 52 53 A dietary sub study is included within IMPROVE CKD, to analyse daily dietary phosphate 54 55 intake using a questionnaire at entry, 52 and 96 week visits. Diet is the main source of 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 25 of 40 BMJ Open
25 1 2 3 4 exogenous phosphate, and dietary phosphate restriction is recommended in treatment 5 6 algorithms prior to initiation of phosphate binder therapy (1). 7 8 9 10 11 12 Bone mineral density 13 14 Bone mineral density (BMD) is also being determined from the aortic CT images at baseline 15 16 For peer review only 17 and at 96 weeks (34). Due to the complexity of CKD MBD and lack of evidence based 18 19 treatment to manage renal bone disease, BMD as determined by dual energy x ray 20 21 absorptiometry (DXA) has not been utilized routinely to predict fracture risk or monitor 22 23 therapy. Low BMD, as a marker of osteoporosis and renal osteodystrophy, however, is a 24 25 considerable component of CKD MBD and recent prospective trials have reported that low 26 27 BMD of the femoral neck and total hip in pre dialysis CKD patients is associated with 28 29 increased fracture rates (35). Improvement in BMD has been reported with the use of 30
31 http://bmjopen.bmj.com/ 32 phosphate binders in contrast to placebo (21) and therefore BMD is an important additional 33 34 outcome for the IMPROVE CKD study. 35 36 37 38 Statistical Considerations 39 on September 30, 2021 by guest. Protected copyright. 40 Sample size 41 42 43 The study is designed to detect a clinically meaningful difference of 1 m/s in PWV between 44 45 the study groups at 96 weeks. Assuming a within group standard deviation of 2.9 m/s, a 46 47 sample size of 356 patients would detect a 1 m/s difference in PWV at the 5% significance 48 49 50 level with 90% statistical power. To account for an estimated 10% study withdrawal rate and 51 52 10% non adherence rate, recruitment of 488 participants is anticipated to be required. No 53 54 provision was made for drop ins given there is no provision for lanthanum carbonate to be 55 56 accessed in the pre dialysis CKD population in Australia, New Zealand and Malaysia. 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 26 of 40
26 1 2 3 4 5 6 7 Analysis 8 9 Outcome data from all randomized participants will be analysed according to the intention to 10 11 12 treat principle. The effect of lanthanum carbonate on PWV at 96 weeks will be estimated 13 14 using analysis of covariance (ANCOVA) to adjust for baseline PWV values. Subgroup 15 16 analyses will beFor performed peer according toreview CKD stage (3b vs only 4), age groups (<60 years, ≥60 17 18 years), presence of diabetes mellitus, and levels of serum phosphate (quartiles) by examining 19 20 treatment by subgroup interactions in linear regression models. Differences in other 21 22 continuous variables between the lanthanum and placebo groups will be analysed by 23 24 25 ANCOVA adjusting for baseline measurements. Differences in the percentage change in 26 27 Agatston scores between the study arms are not expected to be normally distributed and will 28 29 be analysed using the Wilcoxon rank sum test. Differences between treatment groups on 30
31 other categorical variables will be analysed using chi square tests. http://bmjopen.bmj.com/ 32 33 34 35 36 37 Discussion 38
39 on September 30, 2021 by guest. Protected copyright. 40 A recent systematic review and meta analysis which evaluated evidence for correlation 41 42 between the effects of CKD MBD medications, such as phosphate binders, on biochemical 43 44 parameters as well as on patient level end points of cardiovascular disease and mortality in 45 46 47 patients with CKD (28 studies, 6,999 participants), reported that effects on serum phosphate 48 49 levels were weakly and imprecisely correlated with all cause and cardiovascular death. The 50 51 authors of this meta analysis concluded that, as existing data did not exclude a mortality 52 53 benefit with treatment, trials are needed to address patient centred outcomes to evaluate drug 54 55 effectiveness in CKD MBD (36). Another recent network meta analysis of 77 RCTs that 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 27 of 40 BMJ Open
27 1 2 3 4 assessed the effects of different phosphate binders on mortality, cardiovascular disease and 5 6 biochemical parameters (involving 12,562 CKD patients), reported no evidence that any class 7 8 of phosphate binder lowered mortality or cardiovascular events when compared to placebo 9 10 (37). The vast majority of studies however involved dialysis patients (62 trials, 11,009 11 12 patients) and most trials were generally of short duration (median 6 months) with high risks 13 14 15 of bias. Again, these studies highlight the need for further RCTs involving phosphate 16 For peer review only 17 lowering in patients with CKD not on dialysis, with longer duration of intervention and 18 19 assessment of outcomes beyond changes in biochemical parameters of CKD MBD. 20 21 22 23 24 The IMPROVE CKD study, an international, multi centre RCT, plans to determine if 25 26 lanthanum carbonate compared to placebo will improve or attenuate arterial compliance and 27 28 reduce the progression of aortic calcification in patients with CKD. Reduced arterial 29 30 compliance and increased vascular calcification are significant issues for patients with CKD, 31 http://bmjopen.bmj.com/ 32 33 by contributing to their greater cardiovascular morbidity and mortality. At present, there are 34 35 no treatment options that are proven to improve arterial stiffness or reduce vascular 36 37 calcification for patients with CKD MBD, and the cautious guidance of international clinical 38
39 guidelines reflects this lack of evidence. The IMPROVE CKD study will provide evidence on September 30, 2021 by guest. Protected copyright. 40 41 for or against the value of the phosphate binder lanthanum carbonate to affect the rate of 42 43 change of aortic PWV and aortic calcification. Should this study not achieve a separation in 44 45 46 serum phosphate values between the two arms of the trial, any differences in outcomes may 47 48 reflect differences in FGF 23. FGF 23 levels at 96 weeks might be expected to differ between 49 50 study arms, because FGF 23 is reported to fall with lanthanum carbonate therapy; although 51 52 this relationship has not been demonstrated consistently (38, 39). 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 28 of 40
28 1 2 3 4 There is a growing understanding of circadian rhythm and the variability in relation to serum 5 6 phosphate levels, with recent appreciation for the contribution of the nicotinamide 7 8 phosphoribosyltransferase (Nampt)/nicotinamide adenine dinucleotide (NAD) system to the 9 10 regulation of sodium phosphate cotransporters. Nampt is a regulator of the intracellular NAD 11 12 pool and this pathway is involved in renal and intestinal expression of sodium dependent 13 14 15 phosphate transporters (40). One of the potential reasons for the commonly observed 16 For peer review only 17 heterogeneity in response to phosphate binders may be due to inter individual variability in 18 19 transcellular phosphate movement (41). Circadian variation in serum phosphate may not be 20 21 regulated by hormones but determined by the Nampt/NAD system, which affects cellular 22 23 shifts and renal and intestinal phosphate transport; and the time of day serum phosphate is 24 25 measured may be critical to determining treatment effect with interventions directed at 26 27 28 regulating serum phosphate. Morning serum phosphate is now considered less helpful when 29 30 assessing any change from interventions, with the best time to detect a difference in the
31 http://bmjopen.bmj.com/ 32 afternoon. One crossover feeding study in patients with CKD reported the circadian pattern of 33 34 serum phosphate with the lowest concentrations at 0800 hours and highest at 1600 (42). 35 36 Therefore, the effect of lanthanum carbonate on serum phosphate levels may or may not 37 38 indicate a treatment effect, however this contributes to the rationale for why the IMPROVE 39 on September 30, 2021 by guest. Protected copyright. 40 41 CKD study is assessing outcome measures other than serum phosphate to assess efficacy, and 42 43 these other measures will more accurately reflect the impact of modifying phosphate 44 45 homeostasis. 46 47 48 49 Clinical implications of the study 50 51 If the use of lanthanum carbonate in the IMPROVE CKD study has a beneficial effect on 52 53 54 surrogates for cardiovascular disease, this will provide support for the current hypothesis that 55 56 phosphate binders and control of hyperphosphatemia may mitigate adverse cardiovascular 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 29 of 40 BMJ Open
29 1 2 3 4 outcomes in patients with CKD. Although a larger trial would be required to demonstrate a 5 6 benefit on mortality, the use of surrogate cardiovascular outcomes should provide clinicians 7 8 with improved evidence regarding treatment strategies. Importantly, this study using 9 10 lanthanum carbonate, a non calcium based phosphate binder, allows for a more accurate 11 12 assessment of the effect of phosphate binding strategies on vascular calcification, without the 13 14 15 complication of an exogenous calcium load. This may provide evidence for the role of non 16 For peer review only 17 calcium based binders in the pre dialysis CKD population, and help inform CKD MBD 18 19 guidelines that currently lack strong evidence for phosphate control in CKD stages 3 5. In 20 21 addition, the IMPROVE CKD study will provide valuable information regarding the 22 23 relationship between phosphate, FGF 23, arterial compliance and calcification in patients 24 25 with CKD. 26 27 28 29 30 31 http://bmjopen.bmj.com/ 32 33 34 35 36 37 38
39 on September 30, 2021 by guest. Protected copyright. 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 30 of 40
30 1 2 3 4 Author Contributions 5 6 All authors (NDT, EP, NL, CMH, GJE, EMP, AV, SVB, GAB, NCB, KC, JDC, SC, RJF, 7 SGH, LSH, DJ, MJJ, DWJ, PGK, KKL, AM, VP, KRP, CAP, DR, LR, ERS, RJW, and 8 9 AYMW) were involved in design of the study protocol. NDT, EP, NL, CMH, GJE, EMP, AV 10 11 and SVB drafted the manuscript, and all authors approved the final version of the manuscript. 12 13 14 Funding/Support 15 16 The IMPROVE CKDFor study peer was funded review by grants from theonly National Health and Medical 17 18 Research Council (NHMRC) of Australia Project Grant (APP1044302); NHMRC Enabling 19 Grant (ID 631731); NHMRC Programme Grant (APP1092957); and Shire Pharmaceuticals 20 21 Development Limited Clinical Trial Contribution. Study medication (lanthanum carbonate 22 and matching placebo) was supplied by Shire Pharmaceuticals. 23 24 25 26 Competing interests 27 28 NDT has received honoraria, travel support and research funding from Amgen, Shire and 29 30 Sanofi. CH has received research funding from Amgen and Shire. SGH has received 31 honoraria, travel support or research funding from Amgen and Sanofi. DJ has received http://bmjopen.bmj.com/ 32 33 consultancy fees from Sanofi, travel support from Amgen and is a current recipient of an 34 Australian National Health and Medical Research Council Practitioner Fellowship. ERS has 35 36 received research funding from Amgen and Sanofi and owns stock in Calciscon. 37 38
39 on September 30, 2021 by guest. Protected copyright. 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 31 of 40 BMJ Open
31 1 2 3 4 References 5 6 7 1. Kidney Disease: Improving Global Outcomes (KDIGO) CKD MBD Work Group. 8 9 KDIGO clinical practice guideline for the diagnosis, evaluation, prevention, and treatment of 10 11 Chronic Kidney Disease–Mineral and Bone Disorder (CKD MBD). Kidney Int Suppl. 2009; 12 13 113: S1 130. 14 15 16 2. Fort J. For Chronic peer Renal Failure: review A Cardiovascular only Risk Factor. Kidney Int 17 18 2005;68(99):S25 S29. 19 20 3. Hruska K, Mathew S, Lund R, Fang Y, Sugatani T. Cardiovascular risk factors in 21 22 chronic kidney disease: does phosphate qualify? Kidney Int 2011;79:S9 S13. 23 24 4. Jamal SA, Vandermeer B, Raggi P, Mendelssohn DC, Chatterley T, Dorgan M, et al. 25 26 Effect of calcium based versus non calcium based phosphate binders on mortality in patients 27 28 29 with chronic kidney disease: an updated systematic review and meta analysis. The Lancet 30
31 2013;382(9900):1268 1277. http://bmjopen.bmj.com/ 32 33 5. Patel L, Bernard LM, Elder GJ. Sevelamer versus calcium based binders for treatment 34 35 of hyperphosphatemia in CKD: A meta analysis of randomized controlled trials. Clin J Am 36 37 Soc Nephrol. 2016 Feb 5;11(2):232 44 38 39 6. Tonelli M, Sacks F, Pfeffer M, Gao Z, Curhan G. Cholesterol And Recurrent Events on September 30, 2021 by guest. Protected copyright. 40 41 42 Trial Investigators. Relation between serum phosphate level and cardiovascular event rate in 43 44 people with coronary disease. Circulation 2005;112:2627 2633. 45 46 7. Chue CD, Edwards NC, Moody WE, Steeds RP, Townend JN, Ferro CJ. Serum 47 48 phosphate is associated with left ventricular mass in patients with chronic kidney disease: a 49 50 cardiac magnetic resonance study. Heart 2012;98(3):219. 51 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 32 of 40
32 1 2 3 4 8. Six I, Maizel J, Barreto FC, Rangrez AY, Dupont S, Slama M, et al. Effects of 5 6 phosphate on vascular function under normal conditions and influence of the uraemic state. 7 8 Cardiovasc Res 2012;96(1):130 139. 9 10 9. Jüppner H. Phosphate and FGF 23. Kidney Int 2011;79:S24 S27. 11 12 10. Ozkok A, Kekik C, Karahan GE, Sakaci T, Ozel A, Unsal A, et al. FGF 23 associated 13 14 15 with the progression of coronary artery calcification in hemodialysis patients. BMC Nephrol 16 For peer review only 17 2013;14:241 241. 18 19 11. Isakova T, Ix JH, Sprague SM, Raphael KL, Fried L, Gassman JJ, et al. Rationale and 20 21 approaches to phosphate and fibroblast growth factor 23 reduction in CKD. J Am Soc 22 23 Nephrol 2015;26(10):2328 2339. 24 25 12. Kimura K, Saika Y, Otani H, Fujii R, Mune M, Yukawa S. Factors associated with 26 27 28 calcification of the abdominal aorta in hemodialysis patients. Kidney Int Suppl. 29 30 1999;71:S238 41.
31 http://bmjopen.bmj.com/ 32 13. Moe SM, Chen NX. Mechanisms of vascular calcification in chronic kidney disease. J 33 34 Am Soc Nephrol 2008;19(2):213 216. 35 36 14. Nasrallah MM, El Shehaby AR, Salem MM, Osman NA, El Sheikh E, Sharaf El Din 37 38 UAA. Fibroblast growth factor 23 (FGF 23) is independently correlated to aortic 39 on September 30, 2021 by guest. Protected copyright. 40 41 calcification in haemodialysis patients. Nephrol Dial Transplant 2010;25(8):2679 2685. 42 43 15. Scialla JJ, Lau WL, Reilly MP, Isakova T, Yang HY, Crouthamel MH, et al. 44 45 Fibroblast growth factor 23 is not associated with and does not induce arterial calcification. 46 47 Kidney Int 2013;83(6):1159 68. 48 49 16. Habbous S, Przech S, Acedillo R, Sarma S, Garg AX, Martin J. The efficacy and 50 51 safety of sevelamer and lanthanum versus calcium containing and iron based binders in 52 53 54 treating hyperphosphatemia in patients with chronic kidney disease: a systematic review and 55 56 meta analysis. Nephrol Dial Transplant 2017;32(1):111 125. 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 33 of 40 BMJ Open
33 1 2 3 4 17. KDIGOKC MUWG. KDIGO 2017 clinical practice guideline update for the 5 6 diagnosis, evaluation, prevention, and treatment of Chronic Kidney Disease–Mineral and 7 8 Bone Disorder (CKD MBD). Kidney Int Suppl. 2017;7:1 59. 9 10 18. Lopes AA, Tong L, Thumma J, Li Y, Fuller DS, Morgenstern H, et al. Phosphate 11 12 binder use and mortality among hemodialysis patients in the Dialysis Outcomes and Practice 13 14 15 Patterns Study (DOPPS): Evaluation of possible confounding by nutritional status. Am J 16 For peer review only 17 Kidney Dis 2012;60(1):90 101. 18 19 19. Isakova T, Gutiérrez OM, Chang Y, Shah A, Tamez H, Smith K, et al. Phosphorus 20 21 binders and survival on hemodialysis. J Am Soc Nephrol 2009;20(2):388 396. 22 23 20. Fernández Martín JL, Carrero JJ, Benedik M, Bos W J, Covic A, Ferreira A, et al. 24 25 COSMOS: the dialysis scenario of CKD–MBD in Europe. Nephrol Dial Transplant 26 27 28 2013;28(7):1922 1935. 29 30 21. Block GA, Wheeler DC, Persky MS, Kestenbaum B, Ketteler M, Spiegel DM, et al.
31 http://bmjopen.bmj.com/ 32 Effects of phosphate binders in moderate CKD. J Am Soc Nephrol 2012;23(8):1407 1415. 33 34 22. Chue CD, Townend JN, Moody WE, Zehnder D, Wall NA, Harper L, et al. 35 36 Cardiovascular effects of sevelamer in stage 3 CKD. J Am Soc Nephrol 2013;24(5):842 852. 37 38 23. Seifert ME, de las Fuentes L, Rothstein M, Dietzen DJ, Bierhals AJ, Cheng SC, et al. 39 on September 30, 2021 by guest. Protected copyright. 40 41 Effects of phosphate binder therapy on vascular stiffness in early stage chronic kidney 42 43 disease. Am J Nephrol 2013;38(2):158 167. 44 45 24. Harrison TS, Scott LJ. Lanthanum Carbonate. Drugs 2004;64(9):985 996. 46 47 25. Zhang C, Wen J, Li Z, Fan J. Efficacy and safety of lanthanum carbonate on chronic 48 49 kidney disease–mineral and bone disorder in dialysis patients: a systematic review. BMC 50 51 Nephrol 2013;14:226 226. 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 34 of 40
34 1 2 3 4 26. Toussaint ND, Lau KK, Strauss BJ, Polkinghorne KR, Kerr PG. Associations between 5 6 vascular calcification, arterial stiffness and bone mineral density in chronic kidney disease. 7 8 Nephrol Dial Transplant 2008;23(2):586 593. 9 10 27. Pannier B, Guérin AP, Marchais SJ, Safar ME, London GM. Stiffness of capacitive 11 12 and conduit arteries. Hypertension 2005;45(4):592. 13 14 15 28. Blacher J, Guerin AP, Pannier B, Marchais SJ, Safar ME, London GM. Impact of 16 For peer review only 17 aortic stiffness on survival in end stage renal disease. Circulation 1999;99(18):2434. 18 19 29. Tholen S, Klofat K, Pan Cheng R, Schmaderer C, Lutz J, Heemann U, et al. 20 21 Progression of aortic pulse wave velocity in patients with chronic kidney disease. J Clin 22 23 Hypertens 2013;15(11):833 838. 24 25 30. Townsend RR, Anderson AH, Chirinos JA, Feldman HI, Grunwald JE, Nessel L, et 26 27 28 al. Association of pulse wave velocity with chronic kidney disease progression and mortality: 29 30 Findings from the CRIC Study (Chronic Renal Insufficiency Cohort). Hypertension
31 http://bmjopen.bmj.com/ 32 2018;71(6):1101 1107. 33 34 31. Frimodt Møller M, Nielsen AH, Kamper A L, Strandgaard S. Reproducibility of 35 36 pulse wave analysis and pulse wave velocity determination in chronic kidney disease. 37 38 Nephrol Dial Transplant 2008;23(2):594 600. 39 on September 30, 2021 by guest. Protected copyright. 40 41 32. Raggi P, Boulay A, Chasan Taber S, Amin N, Dillon M, Burke SK, et al. Cardiac 42 43 calcification in adult hemodialysis patients: A link between end stage renal disease and 44 45 cardiovascular disease? J Am Coll Cardiol 2002;39(4):695 701. 46 47 33. Brandts A, van Elderen SGC, Westenberg JJM, van der Grond J, van Buchem MA, 48 49 Huisman MV, et al. Association of aortic arch pulse wave velocity with left ventricular mass 50 51 and lacunar brain infarcts in hypertensive patients: assessment with MR imaging. Radiology 52 53 54 2009;253(3):681 688. 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 35 of 40 BMJ Open
35 1 2 3 4 34. Lee SJ, Binkley N, Lubner MG, Bruce RJ, Ziemlewicz TJ, Pickhardt PJ. 5 6 Opportunistic screening for osteoporosis using the sagittal reconstruction from routine 7 8 abdominal CT for combined assessment of vertebral fractures and density. Osteoporos Int. 9 10 2016;27(3):1131 1136. 11 12 35. Yenchek RH, Ix JH, Shlipak MG, Bauer DC, Rianon NJ, Kritchevsky SB, et al. Bone 13 14 15 mineral density and fracture risk in older individuals with CKD. Clin J Amn Soc Nephrol 16 For peer review only 17 2012;7(7):1130 1136. 18 19 36. Palmer SC, Teixeira Pinto A, Saglimbene V, Craig JC, Macaskill P, Tonelli M, et al. 20 21 Association of drug effects on serum parathyroid hormone, phosphorus, and calcium levels 22 23 with mortality in CKD: A meta analysis. Am J Kidney Dis 2015;66(6):962 971. 24 25 37. Palmer SC, Gardner S, Tonelli M, Mavridis D, Johnson DW, Craig JC, et al. 26 27 28 Phosphate binding agents in adults with CKD: A network meta analysis of randomized trials. 29 30 Am J Kidney Dis 2016;68(5):691 702.
31 http://bmjopen.bmj.com/ 32 38. Gonzalez Parra E, Gonzalez Casaus ML, Galán A, Martinez Calero A, Navas V, 33 34 Rodriguez M, et al. Lanthanum carbonate reduces FGF23 in chronic kidney disease Stage 3 35 36 patients. Nephrol Dial Transplant 2011;26(8):2567 2571. 37 38 39. Isakova T, Barchi Chung A, Enfield G, Smith K, Vargas G, Houston J, et al. Effects 39 on September 30, 2021 by guest. Protected copyright. 40 41 of dietary phosphate restriction and phosphate binders on FGF23 levels in CKD. Clin J Am 42 43 Soc Nephrol 2013;8(6):1009 1018. 44 45 40. Miyagawa A, Tatsumi S, Takahama W, et al. The sodium phosphate cotransporter 46 47 family and nicotinamide phosphoribosyltransferase contribute to the daily oscillation of 48 49 plasma inorganic phosphate concentration. Kidney Int 2018;93:1073–1085. 50 51 41. Isakova T, Block G. The phosphate bucket list. Kidney Int 2018; 93(5):1033 1035. 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 36 of 40
36 1 2 3 4 42. Ix JH, Anderson CA, Smits G, Persky MS, Block GA. Effect of dietary phosphate 5 6 intake on the circadian rhythm of serum phosphate concentrations in chronic kidney disease: 7 8 a crossover study. Am J Clin Nutr 2014;100(5):1392 1397. 9 10 43. McIntyre NJ, Fluck RJ, McIntyre CW, Fakis A, Taal MW. Determinants of arterial 11 12 stiffness in chronic kidney disease stage 3. PLoS One. 2013;8(1):e55444. 13 14 15 44. Dart AM, Gatzka CD, Cameron JD, Kingwell BA, Liang YL, Berry KL, Reid CM, 16 For peer review only 17 Jennings GL. Large artery stiffness is not related to plasma cholesterol in older subjects with 18 19 hypertension. Arterioscler Thromb Vasc Biol 2001;24:962 968. 20 21 45. Mitchell GF, Hwang SJ, Vasan RS, Larson MG, Pencina MJ, Hamburg NM, Vita JA, 22 23 Levy D, Benjamin EJ. Arterial stiffness and cardiovascular events: the Framingham heart 24 25 study. Circulation 2010;121:505 511. 26 27 28 46. Dart AM, Cameron JD, Gatzka CD, Willson K, Liang YL, Berry KL, et al. Similar 29 30 effects of treatment on central and brachial blood pressures in polder hypertensive subjects in
31 http://bmjopen.bmj.com/ 32 the second Australian national blood pressure trial. Hypertension 2007;49:1242 1247. 33 34 35 36 37 38 39 on September 30, 2021 by guest. Protected copyright. 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 37 of 40 BMJ Open
37 1 2 3 4 Figures 5 6 7 Figure 1. Schema of the IMPROVE CKD trial 8 9 10 11 12 13 14 15 16 For peer review only 17 18 19 20 21 22 23 24 25 26 27 28 29 30
31 http://bmjopen.bmj.com/ 32 33 34 35 36 37 38
39 on September 30, 2021 by guest. Protected copyright. 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 38 of 40
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 For peer review only 17 18 19 20 21 22 23 24 25 26 27 28 29 30
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39 on September 30, 2021 by guest. Protected copyright. 40 41 42 43 44 45 46 47 210x297mm (300 x 300 DPI) 48 49 50 51 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 39 of 40 BMJ Open
1 BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from 2 3 APPENDIX 4 5 6 7 8 Trial Steering Committee 9 Nigel D Toussaint (Chair), Department of Nephrology, The Royal Melbourne Hospital, 10 11 Parkville, Australia; Eugenia Pedagogos, Epworth Healthcare, Melbourne, Australia; Carmel 12 13 M Hawley, Princess Alexandra Hospital, Brisbane, Australia; Grahame J Elder, Westmead 14 15 Hospital, Westmead, Australia; Elaine M Pascoe, Australasian Kidney Trials Network, 16 Brisbane, Australia; Sunil V Badve, St. George Hospital, Sydney, Australia; Geoffrey A Block, 17 18 Colorado Kidney Care,For Denver, peer United review States; Neil C only Boudville, Sir Charles Gairdner 19 20 Hospital, Perth, Australia; Katrina Campbell, Princess Alexandra Hospital, Brisbane, 21 Australia; James D Cameron, Monash Heart, Monash University, Clayton, Australia; Sylvia 22 23 Chen, Epworth Healthcare, Melbourne, Australia; Randall J Faull, Royal Adelaide Hospital, 24 25 Adelaide, Australia; Stephen G Holt, The Royal Melbourne Hospital, Parkville, Australia; Lai 26 27 S Hooi, Sultanah Aminah Hospital, Johor Bahru, Malaysia; Meg J Jardine, The George Institute 28 for Global Health, Sydney, Australia; Peter G Kerr, Monash Medical Centre, Clayton, 29 30 Australia; Kenneth K Lau, Monash Medical Centre, Clayton, Australia; Vlado Perkovic, The 31 32 George Institute for Global Health, Sydney, Australia; Kevan R Polkinghorne, Monash 33 Medical Centre, Clayton, Australia; Carol A Pollock, Royal North Shore Hospital, Sydney, 34
35 Australia; Donna Reidlinger, Australasian Kidney Trials Network, Brisbane, Australia; http://bmjopen.bmj.com/ 36 37 Edward R Smith, The Royal Melbourne Hospital, Parkville, Australia; Robert J Walker, 38 39 Dunedin Hospital, Dunedin, New Zealand; Angela Yee Moon Wang, Queen Mary Hospital, 40 University of Hong Kong, Hong Kong. 41 42
43 on September 30, 2021 by guest. Protected copyright. 44 Data Safety Monitoring Board 45 46 Bruce C Neal (Chair), Deputy Executive Director, The George Institute for Global Health, and 47 48 Professor of Medicine, University of New South Wales, Sydney, Australia; Andrew B Forbes, 49 50 Department of Epidemiology and Preventive Medicine, Monash University, Clayton, 51 Australia; Christoph Wanner, Division of Nephrology and Hypertension, University Hospital 52 53 of Würzburg, Germany; and David C Wheeler, Centre for Nephrology, Royal Free and 54 55 University College Medical School, London, the United Kingdom. 56 57 58 59 60
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1 BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from 2 3 Australasian Kidney Trials Network 4 5 Australasian Kidney Trials Network (AKTN), Brisbane, Queensland, Australia 6 7 Operational Team 8 9 Carmel M Hawley (Chair, AKTN Operations Secretariat), David W Johnson (Deputy Chair, 10 AKTN Operations Secretariat), Sunil V Badve, Yeong Jee Cho, Darsy Darssan, Magid Fahim, 11 12 Rathika Krishnasamy, Alicia Morrish, Elaine M Pascoe, Peta-Anne Paul-Brent, Donna 13 14 Reidlinger, Laura Robison, Anish Scaria, Andrea Valks, Liza Vergara. 15 16 Executive Committee 17 Carmel M Hawley (Chair), David W Johnson (Deputy Chair), Sunil V Badve, Neil C 18 For peer review only 19 Boudville, Alan Cass, Meg J Jardine, Alicia Morrish, Elaine M Pascoe, Vlado Perkovic, Donna 20 21 Reidlinger. 22 23 24 25 26 27 28 29 30 31 32 33 34
35 http://bmjopen.bmj.com/ 36 37 38 39 40 41 42
43 on September 30, 2021 by guest. Protected copyright. 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
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Can we IMPROVE cardiovascular outcomes through phosphate lowering in CKD? - Rationale and protocol for the IMpact of Phosphate Reduction On Vascular End-points in Chronic Kidney Disease (IMPROVE-CKD) study
ForJournal: peerBMJ Open review only Manuscript ID bmjopen-2018-024382.R1
Article Type: Protocol
Date Submitted by the 09-Oct-2018 Author:
Complete List of Authors: Lioufas, Nicole; Royal Melbourne Hosp, Nephrology; University of Melbourne, Department of Medicine Toussaint, Nigel D.; Royal Melbourne Hosp, Nephrology; University of Melbourne, Department of Medicine Pedagogos, Eugenia; Epworth Healthcare Elder, Grahame; Westmead Hospital, Department of Renal Medicine Badve, Sunil; St. George Hospital, Department of Nephrology Pascoe, Elaine; University of Queensland, Faculty of Medicine; Australasian Kidney Trials Network http://bmjopen.bmj.com/ Valks, Andrea; Australasian Kidney Trials Network, University of Queensland Hawley, Carmel; The University of Queensland
Primary Subject Renal medicine Heading:
Secondary Subject Heading: Research methods
phosphate, mineral metabolism, randomized controlled trial, CKD-MBD, on September 30, 2021 by guest. Protected copyright. Keywords: pulse wave velocity, vascular calcification
For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 1 of 40 BMJ Open
1 1 2 3 4 Title page 5 6 7 Can we IMPROVE cardiovascular outcomes through phosphate lowering 8 9 10 in CKD? – Rationale and protocol for the IMpact of Phosphate Reduction 11 12 On Vascular End-points in Chronic Kidney Disease (IMPROVE-CKD) 13 14 15 study 16 For peer review only 17 1,2 1,2 2,3 18 Nicole LIOUFAS* , Nigel D TOUSSAINT* , Eugenia PEDAGOGOS , Grahame J 19 ELDER4,5, Sunil V BADVE6, Elaine M PASCOE7,8, Andrea VALKS7,8, Carmel M 20 21 HAWLEY7,8,9, on behalf of the IMPROVE-CKD Writing Committee. 22 23 1Department of Nephrology, The Royal Melbourne Hospital, Parkville, Australia, 24 2 3 25 Department of Medicine (RMH), University of Melbourne, Parkville, Australia, Epworth 26 HealthCare, Melbourne, Australia, 4Department of Renal Medicine, Westmead Hospital, 27 28 Westmead, Australia, 5Osteoporosis and Bone Biology Division, Garvan Institute of Medical 29 6 30 Research, Darlinghurst, Australia, Department of Nephrology, St. George Hospital, Sydney, 31 Australia, 7Faculty of Medicine, University of Queensland, Woolloongabba, Australia, http://bmjopen.bmj.com/ 32 33 8Australasian Kidney Trials Network, Brisbane, Australia, 9Department of Nephrology, 34 35 Princess Alexandra Hospital, Woolloongabba, Australia. 36 37 * Co primary authors 38
39 on September 30, 2021 by guest. Protected copyright. 40 Running head: IMPROVE CKD study 41 42 Protocol version: Version 3.0 43 44 Word count: Abstract 287 Text 4184 45 46 Correspondence: Associate Professor Nigel Toussaint 47 48 Department of Nephrology, The Royal Melbourne Hospital, 49 50 Grattan Street, Parkville, Victoria 3052, Australia. 51 E mail: [email protected] 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 2 of 40
2 1 2 3 4 Keywords: arterial compliance, cardiovascular disease, chronic kidney disease, chronic 5 kidney disease mineral and bone disorder (CKD MBD), phosphate, vascular calcification 6 7 8 Full list of members for IMPROVE-CKD Writing Committee: 9 Nigel D Toussaint, The Royal Melbourne Hospital, Parkville, Victoria, Australia; and 10 11 The University of Melbourne, Parkville, Victoria, Australia. 12 Eugenia Pedagogos, Epworth Healthcare, Melbourne, Victoria, Australia. 13 14 Nicole Lioufas, The Royal Melbourne Hospital, Parkville, Victoria, Australia. 15 Carmel M Hawley, Princess Alexandra Hospital, Brisbane, Queensland, Australia. 16 For peer review only 17 Grahame J Elder, Westmead Hospital, Westmead, New South Wales, Australia. 18 Elaine M Pascoe, Australasian Kidney Trials Network, Brisbane, Australia. 19 20 Andrea Valks, Australasian Kidney Trials Network, Brisbane, Australia. 21 Sunil V Badve, St. George Hospital, Sydney, New South Wales, Australia. 22 23 Geoffrey A Block, Colorado Kidney Care, Denver, United States. 24 Neil C Boudville, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia; and 25 26 University of Western Australia, Perth, Western Australia, Australia. 27 Katrina Campbell, Princess Alexandra Hospital, Brisbane, Queensland, Australia. 28 29 James D Cameron, Monash Medical Centre, Clayton, Victoria, Australia. 30 Sylvia SM Chen, Epworth Healthcare, Melbourne, Victoria, Australia. 31 http://bmjopen.bmj.com/ 32 Randall J Faull, Royal Adelaide Hospital, Adelaide, South Australia, Australia. 33 Stephen G Holt, The Royal Melbourne Hospital, Parkville, Victoria, Australia. 34 35 Lai S Hooi, Sultanah Aminah Hospital, Johor Bahru, Malaysia. 36 Dana Jackson, Monash Medical Centre, Clayton, Victoria, Australia. 37 Meg J Jardine, Concord Hospital, Sydney, New South Wales, Australia. 38
39 David W Johnson, Princess Alexandra Hospital, Brisbane, Queensland, Australia; and on September 30, 2021 by guest. Protected copyright. 40 University of Queensland, Brisbane, Queensland, Australia. 41 42 Peter G Kerr, Monash Medical Centre, Clayton, Victoria, Australia. 43 Kenneth K Lau, Monash Medical Centre, Clayton, Victoria, Australia. 44 45 Alicia Morrish, Australasian Kidney Trials Network, Brisbane, Australia. 46 Vlado Perkovic, The George Institute, Sydney, New South Wales, Australia. 47 48 Kevan R Polkinghorne, Monash Medical Centre, Clayton, Victoria, Australia. 49 Carol A Pollock, Royal North Shore Hospital, Sydney, New South Wales, Australia. 50 51 Donna Reidlinger, Australasian Kidney Trials Network, Brisbane, Australia. 52 Laura Robison, Australasian Kidney Trials Network, Brisbane, Australia. 53 54 Edward R Smith, The Royal Melbourne Hospital, Parkville, Victoria, Australia. 55 Robert J Walker, Dunedin Hospital, Dunedin, New Zealand. 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 3 of 40 BMJ Open
3 1 2 3 4 Angela Yee Moon Wang, University of Hong Kong, Queen Mary Hospital, Hong Kong. 5 6 7 8 Abstract 9 10 Introduction: Patients with chronic kidney disease (CKD) are at heightened cardiovascular 11 12 13 risk, which has been associated with abnormalities of bone and mineral metabolism. A deeper 14 15 understanding of these abnormalities should facilitate improved treatment strategies and 16 For peer review only 17 patient level outcomes, but at present there are few large, randomized controlled clinical 18 19 trials to guide management. Positive associations between serum phosphate and fibroblast 20 21 growth factor 23 (FGF 23) and cardiovascular morbidity and mortality in both the general 22 23 and CKD populations have resulted in clinical guidelines suggesting that serum phosphate be 24 25 targeted towards the normal range, although few randomized and placebo controlled studies 26 27 28 have addressed clinical outcomes using interventions to improve phosphate control. Early 29 30 preventive measures to reduce the development and progression of vascular calcification, left
31 http://bmjopen.bmj.com/ 32 ventricular hypertrophy, and arterial stiffness are crucial in patients with CKD. 33 34 Methods and Analysis: We outline the rationale and protocol for an international, multi 35 36 centre, randomized parallel group trial assessing the impact of the non calcium based 37 38 phosphate binder, lanthanum carbonate, compared to placebo on surrogate markers of 39 on September 30, 2021 by guest. Protected copyright. 40 41 cardiovascular disease in a pre dialysis CKD population – the IMPROVE CKD study. The 42 43 primary objective of the IMPROVE CKD study is to determine if use of lanthanum carbonate 44 45 reduces the burden of cardiovascular disease in patients with CKD stages 3b and 4 when 46 47 compared to placebo. The primary end point of the study is change in arterial compliance 48 49 measured by pulse wave velocity over a 96 week period. Secondary outcomes include change 50 51 in aortic calcification and biochemical parameters of serum phosphate, parathyroid hormone 52 53 54 and FGF 23 levels. 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 4 of 40
4 1 2 3 4 Ethics and Dissemination: Ethical approval for the IMPROVE CKD trial was obtained by 5 6 each local Institutional Ethics Committee for all 17 participating sites in Australia, New 7 8 Zealand and Malaysia prior to study commencement. Results of this clinical trial will be 9 10 published in peer reviewed journals and presented at conferences. 11 12
13 14 IMPROVE-CKD registration number ACTRN12610000650099 15 16 For peer review only 17 18 19
20 21 22 Strengths and limitations of this study 23 24 25 Largest cohort and longest in duration for randomized, placebo controlled trial of 26 • 27 28 phosphate binders in non dialysis chronic kidney disease (CKD) population. 29 30 • Assesses potential effects, yet to be determined, of phosphate lowering on arterial 31 http://bmjopen.bmj.com/ 32 compliance and vascular calcification in patients with CKD. 33 34 35 • Avoids exogenous calcium load by using non calcium based phosphate binders in 36 37 blinded fashion to inform clinical guidelines lacking strong evidence for phosphate 38 39 control. on September 30, 2021 by guest. Protected copyright. 40 41 42 • Will provide valuable information regarding relationship between phosphate, FGF 43 44 23, and arterial compliance and calcification in CKD. 45 46 Limitations include potential difficulty in recruitment of large CKD population to 47 • 48 49 assess thrice daily phosphate binders, and possible lack of adherence to study 50 51 medication over 96 week period. 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 5 of 40 BMJ Open
5 1 2 3 4 5 6 7 ‘Chronic Kidney Disease Mineral Bone Disorder’ (CKD MBD) has been accepted 8 9 terminology in nephrology research and clinical practice for more than a decade. This clinical 10 11 entity encompasses intimately related abnormalities of mineral homeostasis, bone turnover 12 13 and mineralization, and vascular and soft tissue calcification, which are almost universal in 14 15 patients with advanced chronic kidney disease (CKD). CKD MBD is a complex and evolving 16 For peer review only 17 area for which international clinical guidelines have been published to provide suggestions 18 19 20 and recommendations on management (1). Just as importantly, these guidelines highlight the 21 22 paucity of clinical studies supporting suggested biochemical targets, and the lack of evidence 23 24 based treatment strategies aimed at reducing the risks of fracture, cardiovascular disease and 25 26 mortality or improving quality of life for individuals with CKD. 27 28 29 30
31 http://bmjopen.bmj.com/ 32 Patients with CKD have significantly increased risks of cardiovascular disease and all cause 33 34 mortality compared to the general population (2), and traditional and CKD specific risk 35 36 factors contribute to this risk (3). Abnormalities of bone and mineral metabolism, and in 37 38 particular abnormal values of serum phosphate, calcium, parathyroid hormone (PTH) and 39 on September 30, 2021 by guest. Protected copyright. 40 fibroblast growth factor 23 (FGF 23), are considered important, however few strong 41 42 recommendations for treatment of these values exist beyond normalising serum phosphate 43 44 45 and lowering PTH to an indeterminate target (1). Minimizing exogenous calcium through 46 47 reducing exposure to calcium based phosphate binders within the CKD population has also 48 49 been suggested as beneficial, citing meta analyses showing mortality benefits of non calcium 50 51 containing phosphate binders over calcium based binders (4, 5), but placebo controlled 52 53 studies are lacking. 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 6 of 40
6 1 2 3 4 Whilst observational studies show associations between higher serum phosphate levels and 5 6 worse clinical outcomes, causality has never been demonstrated. Serum phosphate provides a 7 8 poor measure of overall phosphate balance or the risk of soft tissue calcification in patients 9 10 with CKD, and benefits of phosphate lowering are yet to be demonstrated. Whether a target 11 12 level of serum phosphate will assist in attaining improved outcomes remains controversial 13 14 15 and no randomized controlled trial (RCT) to date has proved that lowering extracellular 16 For peer review only 17 phosphate improves clinical outcomes. The IMPROVE CKD (IMpact of Phosphate 18 19 Reduction On Vascular End points in Chronic Kidney Disease) study is a placebo controlled 20 21 RCT assessing the potential effects of lanthanum carbonate, a non calcium based phosphate 22 23 binder, on surrogate markers of cardiovascular disease in patients with CKD. Here, we 24 25 discuss the rationale and study design of this important trial. 26 27 28 29 30 31 Rationale for a clinical trial http://bmjopen.bmj.com/ 32 33 34 Epidemiological studies in the general population and in patients with CKD have consistently 35 36 shown that serum phosphate levels within and above the upper normal range are 37 38 independently and positively correlated with all cause mortality (6). In patients with CKD, 39 on September 30, 2021 by guest. Protected copyright. 40 cardiovascular mortality, arterial stiffness and progression of renal impairment have also been 41 42 correlated with higher serum phosphate (7, 8). Positive phosphate balance is known to 43 44 45 contribute to rising PTH and FGF 23 values, which in turn, have also been associated with 46 47 adverse clinical outcomes (9, 10). Thus, it is biologically plausible that therapeutic strategies 48 49 aimed at reducing phosphate balance and serum phosphate values in patients with CKD 50 51 might be beneficial. Dietary phosphate absorption is one modifiable determinant of phosphate 52 53 balance and pilot studies that have evaluated phosphate binders, low phosphate diet, or 54 55 nicotinamide (which inhibits intestinal sodium dependent phosphate co transport) in patients 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 7 of 40 BMJ Open
7 1 2 3 4 with CKD have shown a reduction of dietary phosphate absorption, serum phosphate and 5 6 FGF 23 levels (11). However, evidence for the benefit of such strategies on surrogates for 7 8 cardiovascular disease or for CKD progression remains elusive. 9 10 11 12 13 14 Abnormal mineral metabolism, with alterations in the regulation of calcium, phosphate and 15 16 FGF 23, is alsoFor associated peer with the development review of vascular only calcification (12). Although 17 18 mechanisms leading to vascular calcification are incompletely understood, hypotheses 19 20 include a maladaptive repair response to vascular and endothelial damage (13), and 21 22 enhancement of concentration dependent calcium phosphate precipitation and extracellular 23 24 25 matrix deposition due to elevated phosphate levels. Studies also report coronary artery 26 27 calcification associated with elevated FGF 23 values independent of serum phosphate (10, 28 29 14), although this association is not a consistent finding (15). In addition to abnormalities of 30
31 mineral metabolism, exogenous calcium has been associated with the development and http://bmjopen.bmj.com/ 32 33 progression of vascular calcification in patients with CKD. A meta analysis of phosphate 34 35 binders by Jamal et al, analysing 14 RCTs, reported a reduction in mortality associated with 36 37 the use of non calcium containing phosphate binders (4). A more recent meta analysis of 25 38
39 on September 30, 2021 by guest. Protected copyright. 40 eligible studies showed a reduction in all cause mortality with sevelamer versus calcium 41 42 based binders (5). This difference is potentially related to a positive calcium balance in 43 44 patients prescribed calcium based phosphate binders leading to increasing vascular 45 46 calcification. Another meta analysis reviewed the individual contribution of available non 47 48 calcium based phosphate binders, and reported that current data are more robust for 49 50 sevelamer than for lanthanum or iron based binders (16). 51 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 8 of 40
8 1 2 3 4 The recently updated Kidney Disease Improving Global Outcomes (KDIGO) CKD MBD 5 6 Guidelines (17) highlighted the lack of trial data demonstrating that lowering serum 7 8 phosphate improved patient centred outcomes. In fact, the evidence for any phosphate 9 10 lowering intervention is only based on epidemiological studies and biological plausibility. 11 12 Although several recent historical cohort analyses (DOPPS, ArMORR and COSMOS) 13 14 15 suggested that the prescription of phosphate binders to dialysis patients improved survival 16 For peer review only 17 (18 20), these reports were not included in the evidence review for the updated KDIGO 18 19 Guidelines. However, a recent RCT comparing calcium and non calcium based phosphate 20 21 binders with placebo in 148 patients with CKD stages 3 4 (21) was included in the guideline 22 23 update review and reported a minimal reduction of serum phosphate in the active treatment 24 25 groups, no overall effect on FGF 23 and increases in coronary artery calcification for the 26 27 28 combined phosphate binder groups (predominantly associated with the calcium based binder 29 30 arm).
31 http://bmjopen.bmj.com/ 32 33 34 35 Similarly, two placebo controlled RCTs of phosphate lowering in pre dialysis CKD have 36 37 also failed to support the benefit of phosphate lowering in this population (Table 1). Chue et 38
39 on September 30, 2021 by guest. Protected copyright. 40 al. found no significant differences between sevelamer and placebo with regard to left 41 42 ventricular mass, systolic and diastolic function, or pulse wave velocity (PWV) in 109 43 44 patients with CKD after 40 weeks, although only 56% of subjects took ≥80% of the 45 46 prescribed therapy (22). In the adherent subgroup, treatment with sevelamer was associated 47 48 with lower urinary excretion of phosphate and serum FGF 23, although binder use was not 49 50 associated with cardiovascular outcomes of interest such as left ventricular hypertrophy or 51 52 53 arterial compliance. In a smaller study of 38 CKD patients, Seifert et al. reported no 54 55 differences between lanthanum or placebo over 12 months with respect to serum or urinary 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 9 of 40 BMJ Open
9 1 2 3 4 phosphate, or surrogate cardiovascular markers of PWV, carotid artery intima media 5 6 thickness or vascular calcification (23). These results question the efficacy and safety of 7 8 phosphate binders in this population and the updated KDIGO guidelines have amended a 9 10 previous recommendation statement to maintain serum phosphate in the normal range for 11 12 patients with CKD stages 3 5 to now suggest that treatment should focus on patients with 13 14 15 overt hyperphosphatemia, although this recommendation is still based on weak clinical 16 For peer review only 17 evidence. 18 19 20 21 22 Currently there are two relevant RCTs in progress (Table 1). The COMBINE (CKD Optimal 23 24 25 Management With BInders and NicotinamidE) study assesses the effects of lowering serum 26 27 phosphate and FGF 23 levels in patients with CKD stages 3 4 (11). This study aims to recruit 28 29 200 participants and evaluate the use of nicotinamide and lanthanum carbonate in a double 30
31 blind, placebo controlled trial over 12 months. The primary aim of COMBINE is the safety http://bmjopen.bmj.com/ 32 33 and biochemical efficacy of these phosphate lowering agents, although assessments of 34 35 circulating biomarkers of bone and mineral metabolism and magnetic resonance imaging 36 37 (MRI) of intermediate measures of cardiovascular disease will also be measured. Enrolment 38
39 on September 30, 2021 by guest. Protected copyright. 40 for this RCT began in 2015 with results expected in 2018. We have also commenced a large 41 42 multi centre RCT, the IMPROVE CKD study, to investigate the role of phosphate binders in 43 44 early stages of CKD. This trial, conducted over a longer period and with a larger cohort, aims 45 46 to assess potential effects of phosphate lowering on arterial compliance, vascular calcification 47 48 and left ventricular mass. 49 50 51 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 10 of 40
10 1 2 3 4 5 6 7 Table 1. Placebo controlled RCTs of phosphate lowering in patients with CKD stage 3 5 not 8 9 on dialysis assessing surrogate parameters of cardiovascular disease 10 11 12 Study Population Intervention Finding 13 14 Block et al 148 patients Lanthanum Reduced urinary phosphate and 15 16 (PNT)(21) ForCKD3 4 peer carbonate, review serum only phosphate; 17 18 sevelamer Promotion of vascular calcification 19 20 21 carbonate, with binders; 22 23 calcium acetate No difference in PWV 24 25 Chue et al 120 patients Sevelamer Lower urinary phosphate and 26 27 (CRIB CKD3 non carbonate vs FGF 23 (later in compliant 28 29 PHOS)(22) diabetic placebo patients) 30
31 http://bmjopen.bmj.com/ Seifert et al(23) 38 patients Lanthanum vs No differences in serum/urine 32 33 34 CKD3 placebo phosphate, PWV, carotid IMT, 35 36 vascular calcification 37 38 Isakova et al Aimed Lanthanum vs Ongoing
39 on September 30, 2021 by guest. Protected copyright. 40 (COMBINE)(11) recruitment of lanthanum + 41 42 200 patients nicotinamide vs 43 44 CKD3 4 nicotinamide vs 45 46 47 placebo 48 49 IMPROVE CKD Aimed Lanthanum vs Ongoing 50 51 recruitment of placebo 52 53 488 patients 54 55 with CKD3b 4 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 11 of 40 BMJ Open
11 1 2 3 4 5 6 Abbreviations: IMT, intimal medial thickness; PWV, pulse wave velocity; PNT, Phosphate 7 Normalisation Trial; CRIB PHOS, Chronic Renal Impairment in Birmingham – Phosphate study; 8 9 COMBINE, CKD Optimal Management With BInders and NicotinamidE study; IMPROVE CKD, 10 Impact of Phosphate Reduction On Vascular End Points in CKD 11 12 13 14 15 16 For peer review only 17 18 19 Overview of the IMPROVE-CKD Study 20 21 22 Study aims 23 24 25 The primary objective of the IMPROVE CKD study is to determine if use of the non 26 27 calcium based phosphate binder lanthanum carbonate reduces the burden of cardiovascular 28 29 disease in patients with CKD stages 3b and 4 when compared to placebo. The primary end 30 31 point of the study is change in arterial compliance measured by PWV over a 96 week period. http://bmjopen.bmj.com/ 32 33 Secondary outcomes include change in aortic calcification and biochemical parameters of 34 35 36 serum phosphate, PTH and FGF 23 levels. 37 38 39 on September 30, 2021 by guest. Protected copyright. 40 41 Study design, setting and participants 42 43 44 The IMPROVE CKD study is an investigator led, prospective, double blind, randomized 45 46 placebo controlled parallel group trial. Figure 1 demonstrates the overall study design. The 47 48 trial is registered with the Australia and New Zealand Clinical Trial Register 49 50 (ACTRN12610000650099). 51 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 12 of 40
12 1 2 3 4 The IMPROVE CKD study includes patients from 17 nephrology sites in Australia, New 5 6 Zealand and Malaysia with CKD stage 3b and stage 4, aged over 18 years old, and who have 7 8 a serum phosphate level over 1.00 mmol/L (3.10 mg/dL) on at least one occasion in the 6 9 10 months prior to randomization (Table 2). Patient recruitment commenced in 2012, with a plan 11 12 to enrol 488 participants for a 96 week study period. During the recruitment phase of the 13 14 15 study, changes were made to the inclusion and exclusion criteria in order to improve 16 For peer review only 17 feasibility and generalizability of the trial. The changes and rationale are documented in 18 19 Table 3. 20 21 22 23 24 25 26 27 28 29 30
31 http://bmjopen.bmj.com/ 32 33 34 35 36 37 38
39 on September 30, 2021 by guest. Protected copyright. 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 13 of 40 BMJ Open
13 1 2 3 4 5 6 7 8 9 Table 2. Inclusion and Exclusion Criteria for the IMPROVE CKD study 10 11 12 Inclusion criteria 13 14 1. Patients with CKD stages 3b and 4 (eGFR between 15 and 45 ml/min/1.73m2)* 15 16 For peer review only 17 2. Serum phosphate > 1.00 mmol/L (3.10 mg/dL) on at least one occasion in the 18 19 previous 6 months 20 21 3. 18 years or over 22 23 4. Able to give informed consent 24 25 Exclusion criteria 26 27 1. Patients with a history of psychological illness or condition which interferes with 28 29 30 their ability to understand or comply with the requirements of the study
31 http://bmjopen.bmj.com/ 32 2. Renal transplantation 33 34 3. Recent (within 1 month) hospitalization or cardiovascular event 35 36 4. Pregnancy or breast feeding 37 38 5. Medical conditions that impact on phosphate metabolism (apart from CKD), e.g. 39 on September 30, 2021 by guest. Protected copyright. 40 primary hyperparathyroidism or hypoparathyroidism; previous subtotal 41 42 43 parathyroidectomy; gastrointestinal malabsorption disorders such as Crohn’s 44 45 disease, ulcerative colitis, coeliac disease or severe liver dysfunction 46 47 6. Malnutrition, defined as serum albumin < 30 g/L 48 49 7. Serum phosphate ≤ 0.8 mmol/L (2.48 mg/dL) at screening 50 51 8. Atrial fibrillation as documented on ECG performed at screening 52 53 9. Inability to perform PWV 54 55 *eGFR determined using the CKD Epidemiology Collaboration (CKD EPI) equation 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 14 of 40
14 1 2 3 4 Abbreviations: CKD, chronic kidney disease; ECG, electrocardiogram; eGFR, estimated glomerular filtration 5 rate 6 7 8 9 10 11 12 13 14 15 16 For peer review only 17 18 19 20 21 22 23 24 25 26 27 28 29 30
31 http://bmjopen.bmj.com/ 32 33 34 35 36 37 38
39 on September 30, 2021 by guest. Protected copyright. 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from 15 15
As the trial progressed, a small small a progressed, trial the As Exclusion criterion was added asadded criterion was Exclusion Pulse wave velocity; Changes between Changes between Pulse velocity; wave measure. a PWV to obtain inability Protocol versions 2.0 to 3.0 to 2.0 Protocol versions on whom a PWV reading could not be could not be PWV reading a on whom as added therefore This was obtained. order to in criterion exclusion an is power of the study not the ensure individuals by including compromised at unattainable whose is PWV recognised is increasingly screening. It operators, for even experienced that of the small a percentage there is on documented been This has obtained. (24 26). studies other percentage of the population was noted was of the percentage population cannot be PWV on population whom
http://bmjopen.bmj.com/ BMJ Open
The window for serum phosphate serum phosphate The window for results to screen eligible patients was patients eligible results to screen the within be changed initially to of 1.2mmol/L. levels and above below to improve was made Thischange the by study broadening recruitment to review continued Trial log screening a was inclusion criterion this show that for eligibility major to patient barrier level was and the the therefore study change reduced This to 1.0mmol/L. affect the adversely to wasthought not the although because study outcomes Serum phosphate level; Changes Changes level; Serum phosphate for was initially criterion Inclusion >1.2mmol/L level serum phosphate at screening, but was (3.72mg/dL) at one least on >1.2mmol/L changed to months. 6 occasion the previous over then level was The serum phosphate from reduced subsequently to >1.0mmol/L >1.2mmol/L on occasion one least (3.10mg/dL) at 6 over months. the previous 3.0 previous 6 months due to fluctuations fluctuations to due previous 6 months participants. suitable population of between Protocol versions 1.0 to 2.0 to to 2.0 1.0 between versions Protocol
on September 30, 2021 by guest. Protected copyright.
For peer review only For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml The initial introduction of these criteria criteria these of The initial introduction of CKD proportion wasto the increase risk at greater were 3b/4 who subjects as as well disease of cardiovascular of renal increased progression of risk logs of screening Review impairment. that albuminuria/proteinuria showed criteria, exclusion commonest were the as they were therefore removed these a posed essential, considered were not to recruitment, impediment significant was recruitment for and the population increased at already deemed Albuminuria/Proteinuria; Changes Changes Albuminuria/Proteinuria; were urine criteria Initial inclusion (ACR) ratio albumin/creatinine protein/creatinine or >10mg/mmol (PCR) ratio >15mg/mmol. subsequently criteria These were removed. between Protocol versions 1.0 to to 2.0 1.0 Protocol between versions
Rationale for Rationale change Protocol Protocol amendment Issue and Issue and version of protocol Table 3. Protocol amendments for the IMPROVE CKD study for the IMPROVE CKD amendments Table Protocol 3.
Page 15 of 40 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 16 of 40 16 16 http://bmjopen.bmj.com/ BMJ Open study is using a phosphate binder as an binder study phosphate using is a purpose of primary the intervention, of the attenuation the study is cardiovascular outcomes. wasadded level as A phosphate lower that ensure to ancriterion exclusion study where the into are not included may reduction further phosphate health. their adversely affect patients with very low phosphate levels levels low phosphate patients with very on September 30, 2021 by guest. Protected copyright.
For peer review only For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml cardiovascular risk regardless of of risk regardless cardiovascular this Also, for albuminuria/proteinuria. is (PWV) study, velocity wave pulse and end point surrogate the primary which one there is publication only to PWV, links albuminuria/proteinuria considered not sois association this (27). significant
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17 1 2 3 4 Experimental intervention 5 6 7 Lanthanum carbonate (Fosrenol) is a commercial product of Shire Pharmaceuticals for the 8 9 treatment of hyperphosphatemia (28). Upon ingestion, lanthanum ions are released from the 10 11 carbonate as a result of gastric acid secretion in the upper gastrointestinal tract and bind to 12 13 dietary phosphate. The compound lanthanum phosphate is insoluble and lanthanum carbonate 14 15 has been shown to effectively reduce the absorption of dietary phosphate in the CKD 16 For peer review only 17 population. In comparison to calcium based phosphate binders, lanthanum carbonate has 18 19 20 additional benefits of reduced incident hypercalcemia (29). Lanthanum has been studied in 21 22 both pre dialysis and dialysis patients, with significant reduction in serum phosphate in both 23 24 patient groups. 25 26 27 28 The long term safety of lanthanum carbonate in patients with CKD has been reported, with 29 30 randomised prospective studies revealing no evidence of bone accumulation or liver toxicity 31 http://bmjopen.bmj.com/ 32 33 (30, 31), and after more than 850 000 person years of worldwide patient exposure, there is no 34 35 evidence that lanthanum carbonate is associated with adverse safety outcomes in CKD 36 37 patients (30). 38
39 on September 30, 2021 by guest. Protected copyright. 40 41 Treatment randomisation 42 43 44 Participants are randomized 1:1 to two arms involving lanthanum carbonate 500mg three 45 46 times daily with meals or matching placebo three times daily with meals for 96 weeks. Study 47 48 medication is up titrated by local investigators to a total dose of six tablets daily (3000mg/day 49 50 lanthanum carbonate) if serum phosphate remains persistently greater than 1.60 mmol/L 51 52 53 (4.95 mg/dL). Randomization is by a covariate adaptive algorithm minimising imbalance 54 55 across treatments arms in age, presence of diabetes, study site and CKD stage and 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 18 of 40
18 1 2 3 4 implemented via web based access to a central electronic randomization system provided by 5 6 The George Institute in Sydney, Australia. 7 8 9 10 11 12 Study procedures 13 14 Patients who meet the eligibility criteria and provide written informed consent undergo a 15 16 For peer review only 17 baseline visit. A site screening log records the number of participants screened who are 18 19 potentially eligible to participate and the reasons for ineligibility and for non participation if 20 21 eligible. Potentially eligible participants already receiving a phosphate binder at screening 22 23 undergo a 2 week washout period before attending the baseline visit. Tables 4 and 5 outline 24 25 the study schedule visits and laboratory outcome measures for the 96 week trial. Pill counts 26 27 will be undertaken at study visits to assess adherence to study medication. 28 29 30 31 http://bmjopen.bmj.com/ 32 33 Use of concomitant medications in this study will be as per standard of clinical care. Oral 34 35 vitamin D administration, both 1,25 dihydroxy vitamin D (calcitriol) and nutritional vitamin 36 37 D (cholecalciferol), is allowed and can be prescribed at the discretion of the treating 38 39 physician. Calcitriol may be administered to study patients to treat secondary on September 30, 2021 by guest. Protected copyright. 40 41 42 hyperparathyroidism or hypocalcemia as indicated, with a maximal dose of 0.25mcg (one 43 44 tablet) per day. 45 46
47 48 49 In addition to the maximal titrated study medication, calcium, magnesium or aluminium 50 51 based phosphate binders can be prescribed for persistent hyperphosphatemia at the discretion 52 53 54 of the local investigator (recommended for progressive or persistent serum phosphate levels 55 56 >1.60mmol/L); and because these are the only available phosphate lowering agents for pre 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 19 of 40 BMJ Open
19 1 2 3 4 dialysis CKD patients in Australia, New Zealand and Malaysia, this trial will have no 5 6 potential drop ins. 7 8 9 10 11 12 The IMPROVE CKD study is being overseen by the Trial Steering Committee (TSC) and 13 14 centrally coordinated by the Australasian Kidney Trials Network (AKTN) (Appendix). The 15 16 safety of participantsFor is overseen peer by an reviewindependent Data Safetyonly Monitoring Board (DSMB, 17 18 Appendix). Participants, investigators, the AKTN coordinating centre staff and outcome 19 20 assessors are all blinded to the treatment assignment in the IMPROVE CKD study. Any 21 22 serious adverse event will be reported to the AKTN within one working day of investigators 23 24 25 becoming aware of the event; and investigators will be required to report any adverse event 26 27 leading to discontinuation of the study drug. Monitors from the AKTN will review patients' 28 29 records regularly to ensure that all endpoints and serious adverse events will be reported. The 30
31 DSMB will assess unblinded data to safeguard participant interests and enhance the integrity http://bmjopen.bmj.com/ 32 33 of the trial. 34 35 36 37 38
39 on September 30, 2021 by guest. Protected copyright. 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from
END END Page 20 of 40 week 96 Month 24 20 20
Visit 7 Visit 7 week 84 week Month 21Month
Visit 6 Visit 6 week 72 week Month 18Month
Visit Visit 5 week 60week baseline Month 15Month
Visit Visit 4 Weeks postWeeks week 48week Month 12Month
X X X X X X X Visit 3 3 Visit week 36week Month 9Month
(Study ±14window (Study visit is days fromdue date of baseline) X X X X X X X X X Visit 2 Visit week 24 Month 6Month
X X Visit 1 Visit 1 Week Week 12 Month 3Month http://bmjopen.bmj.com/ BMJ Open X X X X X X X X X Baseline
X X X
X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X on September 30, 2021 by guest. Protected copyright. Screening/ Screening/ Randomisation For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml
For peer review only
Visits
Dietitian assisted Dietitian food record^ (for participating sites) Adverse Events recordedAdverse Events (SAEs ADRs)and Medication returnedMedication Medication Medication dispensed Cardiac Cardiac * MRI (for participating sites) Pulse Wave Velocity and Pulse Wave Velocity Augmentation Index CT scan CT – multi slice, non contrast * Concomitant Medications Physical ExaminationPhysical Demographics and Demographics History Medical Electrocardiogram (ECG)Electrocardiogram Participant randomisedParticipant Informed Informed Consent Visit Assessments Visit
* if* participantsthe from after study months12 withdraw and prior to 24 months will beto they do requested a CT ‘close out’ and MRI scan. scans additional will sites diastolic also to Some MRI investigate perform dysfunction study the of component dietary the in enrolled participants ^ for Abbreviations: CT, computed tomography; MRI, resonancemagnetic imaging, ADRs, adverse drug reactions; serious SAEs, eventsadverse Table 4. Schedule of visits for the IMPROVE CKD study study IMPROVE CKD the for of Table visits Schedule 4.
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END END Month 24Month 21 21
84 96 week Visit Visit 7 Month 21Month
Visit Visit 6 Month 18Month
Visit Visit 5 baseline Month 15Month
Weeks postWeeks Visit 4 Visit 4 Month 12
Visit 3 Visit 3 Month 9 Month (Laboratory (Laboratory test is ±14window from days visit date)
Visit Visit 2 Month 6 Month
Visit 1 Visit 1
http://bmjopen.bmj.com/ Week Week 12 24 week week 36 week 48 60 week 72 week week Month 3 BMJ Open
Baseline
X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X X on September 30, 2021 by guest. Protected copyright. Screening/ Screening/ Randomisation
For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml For peer review only Phosphate:creatinine Vitamin D Vitamin binding protein Calcification inhibitorsCalcification (OPG, MGP, fetuin A) Asymmetrical Asymmetrical argininedimethyl (ADMA) Fibroblast Fibroblast growth factor 23 (FGF 23) Centrally Tested Laboratory Assessments 24 Hour UrineHour collection24 excretion – timed Spot urine (ACR,Spot PCR and ratio) Vitamin D(25 D) Vitamin Iron studiesIron Other Other Liver Function Tests Intact Parathyroid Intact Hormone(iPTH) HbA1c *HbA1c Fasting GlucoseFasting Fasting ProfileFasting Serum Lipid C reactive ProteinC reactive (CRP) Biochemistry, Renaland Biochemistry, Liver Function Tests Full Blood CountFull Locally Tested LaboratoryLocally Tested Assessments Visits
diabetes patients with in performed Only * ACR,Abbreviations: albumin:creatinine PCR, ratio; protein:creatinineratio; MGP, protein; matrix OPG, Gla osteoprotegerin Table 5. Laboratory outcome measures in the IMPROVE CKD study IMPROVE CKD in the measures Table outcome Laboratory 5.
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22 1 2 3 4 Primary outcome 5 6 7 The primary outcome of the IMPROVE CKD study is change in large arterial compliance (as 8 9 measured by carotid femoral PWV) at 96 weeks after randomization to lanthanum carbonate 10 11 or placebo. Hyperphosphatemia has been associated with reduced arterial compliance and 12 13 multiple studies have reported a positive relationship between serum phosphate and PWV (8, 14 15 32). PWV has been used to measure arterial compliance and is considered to be a valid 16 For peer review only 17 surrogate for cardiovascular morbidity and mortality (33, 34). PWV also correlates with CKD 18 19 20 stage and increases as CKD progresses (35, 36). In the IMPROVE CKD study, arterial 21 22 compliance is being measured using a SphygmoCor device (AtCor, PWV Inc., Westmead, 23 24 Sydney, Australia) with determination of carotid femoral PWV. Carotid femoral PWV 25 26 measures the interval between pulse waves at the carotid and femoral arteries, with higher 27 28 values representing stiffer vessels. In studies of patients with CKD, mean inter observer and 29 30 day to day reproducibility of PWV measurements have been reported to be acceptable, with 31 http://bmjopen.bmj.com/ 32 33 differences of 0.3 +/ 3.2 m/s and 0.7 +/ 1.9 m/s in some studies (37). Pulse wave analysis is 34 35 also being measured using augmentation index (AI) by the SphygmoCor device as an 36 37 additional outcome. AI represents the difference between early and late systolic peaks of the 38
39 systolic pulse wave contour, divided by pulse pressure (%). All PWV and AI readings will be on September 30, 2021 by guest. Protected copyright. 40 41 reviewed at a central cardiac laboratory by trained study investigators blinded to patient 42 43 details and study medication. 44 45 46 47 48 49 Secondary Outcomes 50 51 Vascular calcification 52 53 Abdominal aortic calcification is being determined using computed tomography (CT) at 54 55 baseline and 96 weeks in the IMPROVE CKD study. If patients exit the study after 12 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 23 of 40 BMJ Open
23 1 2 3 4 months, they will be invited to have an early exit CT scan. Aortic calcification is estimated to 5 6 be present in approximately 60% of patients with CKD stages 4 and 5, and increases in those 7 8 on dialysis, with progressive disease related to dialysis vintage (38). Aortic calcification is 9 10 related to the presence of other vascular disease, as well as to serum phosphate and PTH 11 12 levels. There is an association of aortic calcification and arterial compliance, with 13 14 15 correlations between calcium scoring via CT and PWV (32). CT images will be centrally 16 For peer review only 17 reviewed for calcification scores by a trained radiologist and radiographer blinded to patient 18 19 details and study medication. 20 21 22 23 Left ventricular hypertrophy 24 25 PWV has been associated with increased left ventricular mass and the development of 26 27 28 diastolic dysfunction in hypertensive patients (39). However, left ventricular mass has also 29 30 been associated with the development of hyperphosphatemia independent of PWV (7). In the
31 http://bmjopen.bmj.com/ 32 IMPROVE CKD study, cardiac magnetic resonance imaging (MRI), the gold standard to 33 34 evaluate the development of left ventricular hypertrophy, is being used to measure left 35 36 ventricular mass on a sub cohort of participants at baseline and 96 weeks. If a patient exits 37 38 the study after 12 months, they will be invited to have an exit MRI. MRI images will be 39 on September 30, 2021 by guest. Protected copyright. 40 41 centrally reviewed by cardiologists trained in cardiac MRI and blinded to patient details and 42 43 study medication. 44 45 46 47 Biochemical parameters 48 49 Serum phosphate, calcium and PTH are being assessed at individual sites throughout the 96 50 51 week study period. FGF 23 is being measured 6 monthly using intact and c terminal FGF 23 52 53 54 assays and will be centrally analyzed. Changes in urinary phosphate excretion are also being 55 56 evaluated using 24 hour urine collections. Standard biochemical measurements are being 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 24 of 40
24 1 2 3 4 performed in hospital laboratories with appropriate regulatory accreditation to monitor for 5 6 adverse reactions. Serum and urine samples will also be collected at several time points for 7 8 exploratory analyses. 9 10 11 12 13 14 Dietary phosphate 15 16 For peer review only 17 A dietary sub study is included within IMPROVE CKD, to analyse daily dietary phosphate 18 19 intake using a questionnaire at entry, 52 and 96 week visits. Diet is the main source of 20 21 exogenous phosphate, and dietary phosphate restriction is recommended in treatment 22 23 algorithms prior to initiation of phosphate binder therapy (1). 24 25 26 27 28 29 Bone mineral density 30 31 Bone mineral density (BMD) is also being determined from the aortic CT images at baseline http://bmjopen.bmj.com/ 32 33 34 and at 96 weeks (40). Due to the complexity of CKD MBD and lack of evidence based 35 36 treatment to manage renal bone disease, BMD as determined by dual energy x ray 37 38 absorptiometry (DXA) has not been utilized routinely to predict fracture risk or monitor
39 on September 30, 2021 by guest. Protected copyright. 40 therapy. Low BMD, as a marker of osteoporosis and renal osteodystrophy, however, is a 41 42 considerable component of CKD MBD and recent prospective trials have reported that low 43 44 BMD of the femoral neck and total hip in pre dialysis CKD patients is associated with 45 46 increased fracture rates (41). Improvement in BMD has been reported with the use of 47 48 49 phosphate binders in contrast to placebo (21) and therefore BMD is an important additional 50 51 outcome for the IMPROVE CKD study. 52 53 54 55 Statistical Considerations 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 25 of 40 BMJ Open
25 1 2 3 4 Sample size 5 6 7 The study is designed to detect a clinically meaningful difference of 1 m/s in PWV between 8 9 the study groups at 96 weeks. Assuming a within group standard deviation of 2.9 m/s, a 10 11 sample size of 356 patients would detect a 1 m/s difference in PWV at the 5% significance 12 13 level with 90% statistical power. To account for an estimated 10% study withdrawal rate and 14 15 10% non adherence rate, recruitment of 488 participants is anticipated to be required. No 16 For peer review only 17 allowance was made for drop ins given there is no provision for lanthanum carbonate to be 18 19 20 accessed in the pre dialysis CKD population in Australia, New Zealand and Malaysia. 21 22 23 24 25 Analysis 26 27 28 Outcome data from all randomized participants will be analysed according to the intention to 29 30 treat principle. The effect of lanthanum carbonate on PWV at 96 weeks will be estimated 31 http://bmjopen.bmj.com/ 32 using analysis of covariance (ANCOVA) to adjust for baseline PWV values. Subgroup 33 34 analyses will be performed according to CKD stage (3b vs 4), age groups (<60 years, ≥60 35 36 37 years), presence of diabetes mellitus, and levels of serum phosphate (quartiles) by examining 38
39 treatment by subgroup interactions in linear regression models. Differences in other on September 30, 2021 by guest. Protected copyright. 40 41 continuous variables between the lanthanum and placebo groups will be analysed by 42 43 ANCOVA adjusting for baseline measurements. Differences in the percentage change in 44 45 Agatston scores between the study arms are not expected to be normally distributed and will 46 47 be analysed using the Wilcoxon rank sum test. Differences between treatment groups on 48 49 50 other categorical variables will be analysed using chi square tests. 51 52 53 54 55 56 Patient and public involvement 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 26 of 40
26 1 2 3 4 Patients and the public were not initially involved in the development of this study protocol. 5 6 However, there was a consumer representative on the AKTN Scientific Committee which 7 8 reviewed the protocol, provided input and approved the study before it commenced 9 10 recruitment. 11 12 13 14 15 Ethics and dissemination 16 For peer review only 17 18 Ethical approval for the IMPROVE CKD trial was obtained by each local Institutional Ethics 19 20 Committee (IEC) for each participating site prior to study commencement. This study is 21 22 being conducted in accordance with the Declaration of Helsinki, the National Health and 23 24 25 Medical Research Committee (NHMRC) statement on Human Experimentation, Joint 26 27 NHMRC/AVCC statement and Guidelines on Practical Research, applicable ICH guidelines 28 29 and the Therapeutic Goods Administration (TGA). Results of the IMPROVE CKD study, 30
31 including exploratory outcomes, will be disseminated through publications in international http://bmjopen.bmj.com/ 32 33 peer reviewed journals and presentations at local, national and international scientific 34 35 conferences. Results will also be disseminated to all study participants in the form of a clear 36 37 38 and detailed description of the outcomes, which will be specifically consumer focused.
39 on September 30, 2021 by guest. Protected copyright. 40 41 42 43 44 Discussion 45 46 47 A recent systematic review and meta analysis which evaluated evidence for correlation 48 49 between the effects of CKD MBD medications, such as phosphate binders, on biochemical 50 51 parameters as well as on patient level end points of cardiovascular disease and mortality in 52 53 patients with CKD (28 studies, 6,999 participants), reported that effects on serum phosphate 54 55 levels were weakly and imprecisely correlated with all cause and cardiovascular death (42). 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 27 of 40 BMJ Open
27 1 2 3 4 The authors of this meta analysis concluded that, as existing data did not exclude a mortality 5 6 benefit with treatment, trials are needed to address patient centred outcomes to evaluate drug 7 8 effectiveness in CKD MBD (42). Another recent network meta analysis of 77 RCTs that 9 10 assessed the effects of different phosphate binders on mortality, cardiovascular disease and 11 12 biochemical parameters (involving 12,562 CKD patients), reported no evidence that any class 13 14 15 of phosphate binder lowered mortality or cardiovascular events when compared to placebo 16 For peer review only 17 (43). The vast majority of studies however involved dialysis patients (62 trials, 11,009 18 19 patients) and most trials were generally of short duration (median 6 months) with high risks 20 21 of bias. Again, these studies highlight the need for further RCTs involving phosphate 22 23 lowering in patients with CKD not on dialysis, with longer duration of intervention and 24 25 assessment of outcomes beyond changes in biochemical parameters of CKD MBD. 26 27 28 29 30 The IMPROVE CKD study, an international, multi centre RCT, plans to determine if 31 http://bmjopen.bmj.com/ 32 33 lanthanum carbonate compared to placebo will improve or attenuate arterial compliance and 34 35 reduce the progression of aortic calcification in patients with CKD. Reduced arterial 36 37 compliance and increased vascular calcification are significant issues for patients with CKD, 38
39 by contributing to their greater cardiovascular morbidity and mortality. At present, there are on September 30, 2021 by guest. Protected copyright. 40 41 no treatment options that are proven to improve arterial stiffness or reduce vascular 42 43 calcification for patients with CKD MBD, and the cautious recommendations of international 44 45 46 clinical guidelines reflects this lack of evidence. The IMPROVE CKD study will provide 47 48 evidence for or against the value of the phosphate binder lanthanum carbonate to affect the 49 50 rate of change of aortic PWV and aortic calcification. Should this study not achieve a 51 52 separation in serum phosphate values between the two arms of the trial, any differences in 53 54 outcomes may reflect differences in FGF 23. FGF 23 levels at 96 weeks might be expected to 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 28 of 40
28 1 2 3 4 differ between study arms, because FGF 23 is reported to fall with lanthanum carbonate 5 6 therapy; although this relationship has not been demonstrated consistently (44, 45). 7 8 9 10 11 12 A recent open labelled clinical trial randomized 120 patients with CKD stages 3 4 (and 13 14 serum phosphate >1.47 mmol/L [4.6 mg/dL]) to either lanthanum carbonate, calcium acetate 15 16 or dietary phosphateFor restriction peer for 12 monthsreview (46). For the only 102 patients who completed the 17 18 trial, assessment of biochemical parameters, including FGF 23, as well as vascular 19 20 parameters of coronary artery calcification, PWV, and endothelial dysfunction (as measured 21 22 by reactive hyperemia index), demonstrated no difference in change of any outcome from 23 24 25 baseline to 12 months between the three study arms, except for PTH which was suppressed 26 27 more in those on calcium based phosphate binders. Overall, there was also a mild reduction 28 29 in bone specific alkaline phosphatase (ALP) between baseline and 12 months when results 30
31 from all measures to reduce phosphate absorption were combined, which may potentially http://bmjopen.bmj.com/ 32 33 suggest improved bone turnover with phosphate lowering. This study however raises further 34 35 concerns about the lack of proven benefits of phosphate lowering therapy in the non dialysis 36 37 38 CKD population.
39 on September 30, 2021 by guest. Protected copyright. 40 41 42 43 There is a growing understanding of circadian rhythm and the variability in relation to serum 44 45 phosphate levels, with recent appreciation for the contribution of the nicotinamide 46 47 phosphoribosyltransferase (Nampt)/nicotinamide adenine dinucleotide (NAD) system to the 48 49 50 regulation of sodium phosphate cotransporters. Nampt is a regulator of the intracellular NAD 51 52 pool and this pathway is involved in renal and intestinal expression of sodium dependent 53 54 phosphate transporters (47). One of the potential reasons for the commonly observed 55 56 heterogeneity in response to phosphate binders may be due to inter individual variability in 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 29 of 40 BMJ Open
29 1 2 3 4 transcellular phosphate movement (48). Circadian variation in serum phosphate may not be 5 6 regulated by hormones but determined by the Nampt/NAD system, which affects cellular 7 8 shifts and renal and intestinal phosphate transport; and the time of day serum phosphate is 9 10 measured may be critical to determining treatment effect with interventions directed at 11 12 regulating serum phosphate. Morning serum phosphate is now considered less helpful when 13 14 15 assessing any change from interventions, with the best time to detect a difference in the 16 For peer review only 17 afternoon. One crossover feeding study in patients with CKD reported the circadian pattern of 18 19 serum phosphate with the lowest concentrations at 0800 hours and highest at 1600 (49). 20 21 Therefore, the effect of lanthanum carbonate on serum phosphate levels may or may not 22 23 indicate a treatment effect, however this contributes to the rationale for why the IMPROVE 24 25 CKD study is assessing outcome measures other than serum phosphate to assess efficacy, and 26 27 28 these other measures will more accurately reflect the impact of modifying phosphate 29 30 homeostasis.
31 http://bmjopen.bmj.com/ 32 33 34 Clinical implications of the study 35 36 If the use of lanthanum carbonate in the IMPROVE CKD study has a beneficial effect on 37 38 surrogates for cardiovascular disease, this will provide support for the current hypothesis that 39 on September 30, 2021 by guest. Protected copyright. 40 41 phosphate binders and control of hyperphosphatemia may mitigate adverse cardiovascular 42 43 outcomes in patients with CKD. Although a larger trial would be required to demonstrate a 44 45 benefit on mortality, the use of surrogate cardiovascular outcomes should provide clinicians 46 47 with improved evidence regarding treatment strategies. Importantly, this study using 48 49 lanthanum carbonate, a non calcium based phosphate binder, allows for a more accurate 50 51 assessment of the effect of phosphate binding strategies on vascular calcification, without the 52 53 54 complication of an exogenous calcium load. This may provide evidence for the role of non 55 56 calcium based binders in the pre dialysis CKD population, and help inform CKD MBD 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 30 of 40
30 1 2 3 4 guidelines that currently lack strong evidence for phosphate control in CKD stages 3 5. In 5 6 addition, the IMPROVE CKD study will provide valuable information regarding the 7 8 relationship between phosphate, FGF 23, arterial compliance and calcification in patients 9 10 with CKD. 11 12 13 14 15 16 Author ContributionsFor peer review only 17 18 All authors (NDT, EP, NL, CMH, GJE, EMP, AV, SVB, GAB, NCB, KC, JDC, SC, RJF, 19 SGH, LSH, DJ, MJJ, DWJ, PGK, KKL, AM, VP, KRP, CAP, DR, LR, ERS, RJW, and 20 21 AYMW) were involved in study design and concept. NDT, EP, NL, CMH, GJE, EMP, AV 22 23 and SVB drafted the manuscript, and all authors approved the final version of the manuscript. 24 25 26 Funding/Support 27 28 The IMPROVE CKD study was funded by grants from the National Health and Medical 29 30 Research Council (NHMRC) of Australia Project Grant (APP1044302); NHMRC Enabling 31 Grant (ID 631731); NHMRC Programme Grant (APP1092957); and Shire Pharmaceuticals http://bmjopen.bmj.com/ 32 33 Development Limited Clinical Trial Contribution. Study medication (lanthanum carbonate 34 35 and matching placebo) was supplied by Shire Pharmaceuticals. 36 37 38 Disclaimer 39 on September 30, 2021 by guest. Protected copyright. 40 The funders had no role in the study design; writing of the report; or the decision to submit 41 42 the report for publication. 43 44 45 Competing interests 46 47 NDT has received honoraria, travel support and research funding from Amgen, Shire and 48 49 Sanofi. CMH has received research funding from Amgen and Shire. GJE has received 50 honoraria, travel support and research funding from Amgen and Sanofi. SGH has received 51 52 honoraria, travel support or research funding from Amgen and Sanofi. DWJ has received 53 consultancy fees from Sanofi, travel support from Amgen and is a current recipient of an 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 31 of 40 BMJ Open
31 1 2 3 4 Australian National Health and Medical Research Council Practitioner Fellowship. ERS has 5 received research funding from Amgen and Sanofi and owns stock in Calciscon. 6 7 8 9 10 References 11 12 13 1. Kidney Disease: Improving Global Outcomes (KDIGO) CKD MBD Work Group. 14 15 KDIGO clinical practice guideline for the diagnosis, evaluation, prevention, and treatment of 16 For peer review only 17 18 Chronic Kidney Disease–Mineral and Bone Disorder (CKD MBD). Kidney Int Suppl. 2009; 19 20 113: S1 130. 21 22 2. Fort J. Chronic Renal Failure: A Cardiovascular Risk Factor. Kidney Int 23 24 2005;68(99):S25 S29. 25 26 3. Hruska K, Mathew S, Lund R, Fang Y, Sugatani T. Cardiovascular risk factors in 27 28 chronic kidney disease: does phosphate qualify? Kidney Int 2011;79:S9 S13. 29 30
31 4. Jamal SA, Vandermeer B, Raggi P, Mendelssohn DC, Chatterley T, Dorgan M, et al. http://bmjopen.bmj.com/ 32 33 Effect of calcium based versus non calcium based phosphate binders on mortality in patients 34 35 with chronic kidney disease: an updated systematic review and meta analysis. The Lancet 36 37 2013;382(9900):1268 1277. 38 39 5. Patel L, Bernard LM, Elder GJ. Sevelamer versus calcium based binders for treatment on September 30, 2021 by guest. Protected copyright. 40 41 of hyperphosphatemia in CKD: A meta analysis of randomized controlled trials. Clin J Am 42 43 44 Soc Nephrol. 2016 Feb 5;11(2):232 44 45 46 6. Tonelli M, Sacks F, Pfeffer M, Gao Z, Curhan G. Cholesterol And Recurrent Events 47 48 Trial Investigators. Relation between serum phosphate level and cardiovascular event rate in 49 50 people with coronary disease. Circulation 2005;112:2627 2633. 51 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 32 of 40
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31 http://bmjopen.bmj.com/ 32 12. Kimura K, Saika Y, Otani H, Fujii R, Mune M, Yukawa S. Factors associated with 33 34 calcification of the abdominal aorta in hemodialysis patients. Kidney Int Suppl. 35 36 1999;71:S238 41. 37 38 13. Moe SM, Chen NX. Mechanisms of vascular calcification in chronic kidney disease. J 39 on September 30, 2021 by guest. Protected copyright. 40 41 Am Soc Nephrol 2008;19(2):213 216. 42 43 14. Nasrallah MM, El Shehaby AR, Salem MM, Osman NA, El Sheikh E, Sharaf El Din 44 45 UAA. Fibroblast growth factor 23 (FGF 23) is independently correlated to aortic 46 47 calcification in haemodialysis patients. Nephrol Dial Transplant 2010;25(8):2679 2685. 48 49 15. Scialla JJ, Lau WL, Reilly MP, Isakova T, Yang HY, Crouthamel MH, et al. 50 51 Fibroblast growth factor 23 is not associated with and does not induce arterial calcification. 52 53 54 Kidney Int 2013;83(6):1159 68. 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 33 of 40 BMJ Open
33 1 2 3 4 16. Habbous S, Przech S, Acedillo R, Sarma S, Garg AX, Martin J. The efficacy and 5 6 safety of sevelamer and lanthanum versus calcium containing and iron based binders in 7 8 treating hyperphosphatemia in patients with chronic kidney disease: a systematic review and 9 10 meta analysis. Nephrol Dial Transplant 2017;32(1):111 125. 11 12 17. KDIGOKC MUWG. KDIGO 2017 clinical practice guideline update for the 13 14 15 diagnosis, evaluation, prevention, and treatment of Chronic Kidney Disease–Mineral and 16 For peer review only 17 Bone Disorder (CKD MBD). Kidney Int Suppl. 2017;7:1 59. 18 19 18. Lopes AA, Tong L, Thumma J, Li Y, Fuller DS, Morgenstern H, et al. Phosphate 20 21 binder use and mortality among hemodialysis patients in the Dialysis Outcomes and Practice 22 23 Patterns Study (DOPPS): Evaluation of possible confounding by nutritional status. Am J 24 25 Kidney Dis 2012;60(1):90 101. 26 27 28 19. Isakova T, Gutiérrez OM, Chang Y, Shah A, Tamez H, Smith K, et al. Phosphorus 29 30 binders and survival on hemodialysis. J Am Soc Nephrol 2009;20(2):388 396.
31 http://bmjopen.bmj.com/ 32 20. Fernández Martín JL, Carrero JJ, Benedik M, Bos W J, Covic A, Ferreira A, et al. 33 34 COSMOS: the dialysis scenario of CKD–MBD in Europe. Nephrol Dial Transplant 35 36 2013;28(7):1922 1935. 37 38 21. Block GA, Wheeler DC, Persky MS, Kestenbaum B, Ketteler M, Spiegel DM, et al. 39 on September 30, 2021 by guest. Protected copyright. 40 41 Effects of phosphate binders in moderate CKD. J Am Soc Nephrol 2012;23(8):1407 1415. 42 43 22. Chue CD, Townend JN, Moody WE, Zehnder D, Wall NA, Harper L, et al. 44 45 Cardiovascular effects of sevelamer in stage 3 CKD. J Am Soc Nephrol 2013;24(5):842 852. 46 47 23. Seifert ME, de las Fuentes L, Rothstein M, Dietzen DJ, Bierhals AJ, Cheng SC, et al. 48 49 Effects of phosphate binder therapy on vascular stiffness in early stage chronic kidney 50 51 disease. Am J Nephrol 2013;38(2):158 167. 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 34 of 40
34 1 2 3 4 24. Dart AM, Gatzka CD, Cameron JD, Kingwell BA, Liang YL, Berry KL, Reid CM, 5 6 Jennings GL. Large artery stiffness is not related to plasma cholesterol in older subjects with 7 8 hypertension. Arterioscler Thromb Vasc Biol 2001;24:962 968. 9 10 25. Mitchell GF, Hwang SJ, Vasan RS, Larson MG, Pencina MJ, Hamburg NM, Vita JA, 11 12 Levy D, Benjamin EJ. Arterial stiffness and cardiovascular events: the Framingham heart 13 14 15 study. Circulation 2010;121:505 511. 16 For peer review only 17 26. Dart AM, Cameron JD, Gatzka CD, Willson K, Liang YL, Berry KL, et al. Similar 18 19 effects of treatment on central and brachial blood pressures in polder hypertensive subjects in 20 21 the second Australian national blood pressure trial. Hypertension 2007;49:1242 1247. 22 23 27. McIntyre NJ, Fluck RJ, McIntyre CW, Fakis A, Taal MW. Determinants of arterial 24 25 stiffness in chronic kidney disease stage 3. PLoS One. 2013;8(1):e55444. 26 27 28 28. Harrison TS, Scott LJ. Lanthanum Carbonate. Drugs 2004;64(9):985 996. 29 30 29. Zhang C, Wen J, Li Z, Fan J. Efficacy and safety of lanthanum carbonate on chronic
31 http://bmjopen.bmj.com/ 32 kidney disease–mineral and bone disorder in dialysis patients: a systematic review. BMC 33 34 Nephrol 2013;14:226 226. 35 36 30. Hutchison AJ, Wilson RJ, Garafola S, Copley JB. Lanthanum carbonate: safety data 37 38 after 10 years. Nephrology (Carlton). 2016;21(12):987 994. 39 on September 30, 2021 by guest. Protected copyright. 40 41 31. Zhai CJ, Yang XY, Sun J, Wang R. Efficacy and safety of lanthanum carbonate 42 43 versus calcium based phosphate binders in patients with chronic kidney disease: a systematic 44 45 review and meta analysis. Int Urol Nephrol. 2015;47(3):527 35. 46 47 32. Toussaint ND, Lau KK, Strauss BJ, Polkinghorne KR, Kerr PG. Associations between 48 49 vascular calcification, arterial stiffness and bone mineral density in chronic kidney disease. 50 51 Nephrol Dial Transplant 2008;23(2):586 593. 52 53 54 33. Pannier B, Guérin AP, Marchais SJ, Safar ME, London GM. Stiffness of capacitive 55 56 and conduit arteries. Hypertension 2005;45(4):592. 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 35 of 40 BMJ Open
35 1 2 3 4 34. Blacher J, Guerin AP, Pannier B, Marchais SJ, Safar ME, London GM. Impact of 5 6 aortic stiffness on survival in end stage renal disease. Circulation 1999;99(18):2434. 7 8 35. Tholen S, Klofat K, Pan Cheng R, Schmaderer C, Lutz J, Heemann U, et al. 9 10 Progression of aortic pulse wave velocity in patients with chronic kidney disease. J Clin 11 12 Hypertens 2013;15(11):833 838. 13 14 15 36. Townsend RR, Anderson AH, Chirinos JA, Feldman HI, Grunwald JE, Nessel L, et 16 For peer review only 17 al. Association of pulse wave velocity with chronic kidney disease progression and mortality: 18 19 Findings from the CRIC Study (Chronic Renal Insufficiency Cohort). Hypertension 20 21 2018;71(6):1101 1107. 22 23 37. Frimodt Møller M, Nielsen AH, Kamper A L, Strandgaard S. Reproducibility of 24 25 pulse wave analysis and pulse wave velocity determination in chronic kidney disease. 26 27 28 Nephrol Dial Transplant 2008;23(2):594 600. 29 30 38. Raggi P, Boulay A, Chasan Taber S, Amin N, Dillon M, Burke SK, et al. Cardiac
31 http://bmjopen.bmj.com/ 32 calcification in adult hemodialysis patients: A link between end stage renal disease and 33 34 cardiovascular disease? J Am Coll Cardiol 2002;39(4):695 701. 35 36 39. Brandts A, van Elderen SGC, Westenberg JJM, van der Grond J, van Buchem MA, 37 38 Huisman MV, et al. Association of aortic arch pulse wave velocity with left ventricular mass 39 on September 30, 2021 by guest. Protected copyright. 40 41 and lacunar brain infarcts in hypertensive patients: assessment with MR imaging. Radiology 42 43 2009;253(3):681 688. 44 45 40. Lee SJ, Binkley N, Lubner MG, Bruce RJ, Ziemlewicz TJ, Pickhardt PJ. 46 47 Opportunistic screening for osteoporosis using the sagittal reconstruction from routine 48 49 abdominal CT for combined assessment of vertebral fractures and density. Osteoporos Int. 50 51 2016;27(3):1131 1136. 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 36 of 40
36 1 2 3 4 41. Yenchek RH, Ix JH, Shlipak MG, Bauer DC, Rianon NJ, Kritchevsky SB, et al. Bone 5 6 mineral density and fracture risk in older individuals with CKD. Clin J Am Soc Nephrol 7 8 2012;7(7):1130 1136. 9 10 42. Palmer SC, Teixeira Pinto A, Saglimbene V, Craig JC, Macaskill P, Tonelli M, et al. 11 12 Association of drug effects on serum parathyroid hormone, phosphorus, and calcium levels 13 14 15 with mortality in CKD: A meta analysis. Am J Kidney Dis 2015;66(6):962 971. 16 For peer review only 17 43. Palmer SC, Gardner S, Tonelli M, Mavridis D, Johnson DW, Craig JC, et al. 18 19 Phosphate binding agents in adults with CKD: A network meta analysis of randomized trials. 20 21 Am J Kidney Dis 2016;68(5):691 702. 22 23 44. Gonzalez Parra E, Gonzalez Casaus ML, Galán A, Martinez Calero A, Navas V, 24 25 Rodriguez M, et al. Lanthanum carbonate reduces FGF23 in chronic kidney disease Stage 3 26 27 28 patients. Nephrol Dial Transplant 2011;26(8):2567 2571. 29 30 45. Isakova T, Barchi Chung A, Enfield G, Smith K, Vargas G, Houston J, et al. Effects
31 http://bmjopen.bmj.com/ 32 of dietary phosphate restriction and phosphate binders on FGF23 levels in CKD. Clin J Am 33 34 Soc Nephrol 2013;8(6):1009 1018. 35 36 46. Kovesdy CP, Lu JL, Wall BM, Gyamlani G, Naseer A, Wallick A et al. Changes with 37 38 lanthanum carbonate, calcium acetate, and phoshorus restriction in CKD: A randomized 39 on September 30, 2021 by guest. Protected copyright. 40 41 controlled trial. KI Reports 2018;3(4):897 904. 42 43 47. Miyagawa A, Tatsumi S, Takahama W, et al. The sodium phosphate cotransporter 44 45 family and nicotinamide phosphoribosyltransferase contribute to the daily oscillation of 46 47 plasma inorganic phosphate concentration. Kidney Int 2018;93:1073–1085. 48 49 48. Isakova T, Block G. The phosphate bucket list. Kidney Int 2018; 93(5):1033 1035. 50 51 49. Ix JH, Anderson CA, Smits G, Persky MS, Block GA. Effect of dietary phosphate 52 53 54 intake on the circadian rhythm of serum phosphate concentrations in chronic kidney disease: 55 56 a crossover study. Am J Clin Nutr 2014;100(5):1392 1397. 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from Page 37 of 40 BMJ Open
37 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 Figures For peer review only 17 18 19 Figure 1. Schema of the IMPROVE CKD trial 20 21 22 23 24 25 26 27 28 29 30
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39 on September 30, 2021 by guest. Protected copyright. 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from BMJ Open Page 38 of 40
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 For peer review only 17 18 19 20 21 22 23 24 25 26 27 28 29 30
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39 on September 30, 2021 by guest. Protected copyright. 40 41 42 43 44 45 46 47 210x297mm (300 x 300 DPI) 48 49 50 51 52 53 54 55 56 57 58 59 60 For peer review only - http://bmjopen.bmj.com/site/about/guidelines.xhtml Page 39 of 40 BMJ Open
1 BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from 2 3 APPENDIX 4 5 6 7 8 Trial Steering Committee 9 Nigel D Toussaint (Chair), Department of Nephrology, The Royal Melbourne Hospital, 10 11 Parkville, Australia; Eugenia Pedagogos, Epworth Healthcare, Melbourne, Australia; Carmel 12 13 M Hawley, Princess Alexandra Hospital, Brisbane, Australia; Grahame J Elder, Westmead 14 15 Hospital, Westmead, Australia; Elaine M Pascoe, Australasian Kidney Trials Network, 16 Brisbane, Australia; Sunil V Badve, St. George Hospital, Sydney, Australia; Geoffrey A Block, 17 18 Colorado Kidney Care,For Denver, peer United review States; Neil C only Boudville, Sir Charles Gairdner 19 20 Hospital, Perth, Australia; Katrina Campbell, Princess Alexandra Hospital, Brisbane, 21 Australia; James D Cameron, Monash Heart, Monash University, Clayton, Australia; Sylvia 22 23 Chen, Epworth Healthcare, Melbourne, Australia; Randall J Faull, Royal Adelaide Hospital, 24 25 Adelaide, Australia; Stephen G Holt, The Royal Melbourne Hospital, Parkville, Australia; Lai 26 27 S Hooi, Sultanah Aminah Hospital, Johor Bahru, Malaysia; Meg J Jardine, The George Institute 28 for Global Health, Sydney, Australia; Peter G Kerr, Monash Medical Centre, Clayton, 29 30 Australia; Kenneth K Lau, Monash Medical Centre, Clayton, Australia; Vlado Perkovic, The 31 32 George Institute for Global Health, Sydney, Australia; Kevan R Polkinghorne, Monash 33 Medical Centre, Clayton, Australia; Carol A Pollock, Royal North Shore Hospital, Sydney, 34
35 Australia; Donna Reidlinger, Australasian Kidney Trials Network, Brisbane, Australia; http://bmjopen.bmj.com/ 36 37 Edward R Smith, The Royal Melbourne Hospital, Parkville, Australia; Robert J Walker, 38 39 Dunedin Hospital, Dunedin, New Zealand; Angela Yee Moon Wang, Queen Mary Hospital, 40 University of Hong Kong, Hong Kong. 41 42
43 on September 30, 2021 by guest. Protected copyright. 44 Data Safety Monitoring Board 45 46 Bruce C Neal (Chair), Deputy Executive Director, The George Institute for Global Health, and 47 48 Professor of Medicine, University of New South Wales, Sydney, Australia; Andrew B Forbes, 49 50 Department of Epidemiology and Preventive Medicine, Monash University, Clayton, 51 Australia; Christoph Wanner, Division of Nephrology and Hypertension, University Hospital 52 53 of Würzburg, Germany; and David C Wheeler, Centre for Nephrology, Royal Free and 54 55 University College Medical School, London, the United Kingdom. 56 57 58 59 60
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1 BMJ Open: first published as 10.1136/bmjopen-2018-024382 on 21 February 2019. Downloaded from 2 3 Australasian Kidney Trials Network 4 5 Australasian Kidney Trials Network (AKTN), Brisbane, Queensland, Australia 6 7 Operational Team 8 9 Carmel M Hawley (Chair, AKTN Operations Secretariat), David W Johnson (Deputy Chair, 10 AKTN Operations Secretariat), Sunil V Badve, Yeong Jee Cho, Darsy Darssan, Magid Fahim, 11 12 Rathika Krishnasamy, Alicia Morrish, Elaine M Pascoe, Peta-Anne Paul-Brent, Donna 13 14 Reidlinger, Laura Robison, Anish Scaria, Andrea Valks, Liza Vergara. 15 16 Executive Committee 17 Carmel M Hawley (Chair), David W Johnson (Deputy Chair), Sunil V Badve, Neil C 18 For peer review only 19 Boudville, Alan Cass, Meg J Jardine, Alicia Morrish, Elaine M Pascoe, Vlado Perkovic, Donna 20 21 Reidlinger. 22 23 24 25 26 27 28 29 30 31 32 33 34
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43 on September 30, 2021 by guest. Protected copyright. 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60
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