NILVAD Protocol: a European Multicentre Double-Blind Placebo-Controlled Trial of Nilvadipine in Mild-To-Moderate Alzheimer’S Disease
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Open Access Protocol NILVAD protocol: a European multicentre double-blind placebo-controlled trial of nilvadipine in mild-to-moderate Alzheimer’s disease Brian Lawlor,1 Sean Kennelly,1 Sarah O’Dwyer,1 Fiona Cregg,2 Cathal Walsh,2 Robert Coen,1 Rose Anne Kenny,1 Robert Howard,3 Caroline Murphy,3 Jessica Adams,3 Leslie Daly,4 Ricardo Segurado,4 Siobhan Gaynor,5 Fiona Crawford,6 Michael Mullan,6 Ugo Lucca,7 Rita Banzi,7 Florence Pasquier,8 Laetitia Breuilh,8 Matthias Riepe,9 Janos Kalman,10 Anders Wallin,11 Anne Borjesson,11 William Molloy,12 Magda Tsolaki,13 Marcel Olde Rikkert14 To cite: Lawlor B, Kennelly S, ABSTRACT ’ et al Strengths and limitations of this study O Dwyer S, . NILVAD Introduction: This study is a European multicentre, protocol: a European randomised, double-blind, placebo-controlled trial ▪ multicentre double-blind Large European multicentre double-blind, rando- investigating the efficacy and safety of nilvadipine as a placebo-controlled trial of mised placebo-controlled trial. nilvadipine in mild-to- disease course modifying treatment for mild-to- ▪ Investigator driven. ’ moderate Alzheimer’s moderate Alzheimer s disease (AD) in a phase III study ▪ Testing a repositioned medication with a proven disease. BMJ Open 2014;4: that will run for a period of 82 weeks with a treatment safety profile and approved for the treatment of e006364. doi:10.1136/ period of 78 weeks. hypertension. bmjopen-2014-006364 Methods and analysis: Adult patients, males and ▪ Does not test the disease modifying efficacy and females over 50 years with mild-to-moderate AD as safety of nilvadipine at the predementia stage. ▸ Prepublication history for defined by the National Institute of Neurological and this paper is available online. Communicative Disorders and Stroke/Alzheimer’s To view these files please disease and Related Disorders Association (NINCDS- visit the journal online ADRDA) criteria, will be included in the study. It aims Trial registration number: EUDRACT Reference (http://dx.doi.org/10.1136/ to recruit a total of 500 patients with AD; 250 in the Number: 2012-002764-27. bmjopen-2014-006364). nilvadipine group and 250 in the placebo group. Participants will be randomised to receive nilvadipine, Received 26 August 2014 Accepted 5 September 2014 an 8 mg overencapsulated, sustained release capsule, or a matching overencapsulated placebo (sugar pill) for INTRODUCTION a period of 78 weeks of treatment. The primary efficacy outcome measure in this study is the change in The current disappointing state of clinical cognitive function as assessed by the Alzheimer’s trials aimed at advancing therapeutic inter- disease Assessment Scale (ADAS-Cog 12) from ventions for Alzheimer’s disease (AD) has baseline to the end of treatment duration (78 weeks). necessitated the need for development of There are two key secondary outcome measures, the novel strategies that target multiple aspects Clinical Dementia Rating Scale Sum of Boxes (CDR-sb) of the pathogenic process in this neurode- and the Disability Assessment for Dementia (DAD). If a generative condition. Furthermore, ideally, statistically significant effect is seen in the primary any novel drugs or compounds tested would outcome, CDR-sb will be considered to be a coprimary have a demonstrated safety profile in order end point and only the DAD will contribute to the to expedite the path to clinical application. secondary outcome analysis. Calcium antagonists or calcium channel Ethics and dissemination: The study and all fi subsequent amendments have received ethical approval blockers (CCBs) were rst introduced over For numbered affiliations see within each participating country according to national 25 years ago as coronary vasodilators for the end of article. regulations. Each participant will provide written treatment of coronary heart disease, and consent to participate in the study. All participants will have since achieved notable recognition in 1 Correspondence to remain anonymised throughout and the results of the the treatment of arterial hypertension. Prof. Brian Lawlor; study will be published in an international peer- Nilvadipine (trade name: Nivadil), a dihydro- [email protected] reviewed journal. pyridine (DHP) calcium channel antagonist, Lawlor B, et al. BMJ Open 2014;4:e006364. doi:10.1136/bmjopen-2014-006364 1 Open Access is currently licensed to treat patients with hypertension.2 required discontinuation of the medication throughout However, recent research has highlighted other proper- this study, highlighting that nilvadipine is well tolerated ties of certain CCBs, including nilvadipine, suggesting in patients with AD and has demonstrated safety as a that they are protective not just against stroke-related licensed antihypertensive treatment. dementia, but also independently against AD.3 In summary, this study will investigate the safety and Research to date has suggested that the AD preventive efficacy of nilvadipine as a disease-modifying treatment effect of DHP CCBs, may not be mediated through their in patients with mild-to-moderate AD over a period of antihypertensive effects, but rather via an anti-β-amyloid 18 months across nine countries in Europe including (Aβ) mechanism where the accumulation of Aβ in the Ireland, Germany, Greece, France, Holland, Hungary, brain is reduced by altering Aβ production in the brain Italy, Sweden and the UK. and Aβ clearance across the blood–brain barrier (BBB). Overall, the aim is to build on the initial studies of nil- Paris et al investigated the effects of a number of com- vadipine as a treatment for AD by investigating its effi- monly used antihypertensive DHPs and non-DHPs on cacy and establish its safety profile in a phase III Aβ production both in vitro and in vivo and found that double-blind, randomised, placebo-controlled trial. not all DHPs are equal. Nilvadipine and amlodipine were found to significantly lower Aβ40 as well as Aβ42 in vitro production , however, other DHPs and non-DHPs METHODS AND ANALYSIS β β had little effect or even increased A 40 and A 42 pro- Trial design in vitro in vivo duction . The studies using transgenic This is a multicentre, randomised, double-blind, placebo- mouse models of AD (Tg PS1/APPsw) highlighted nilva- controlled study of nilvadipine compared with placebo. β dipine reduced levels of A in the brain and, further- Eligible patients will be randomly assigned to receive β more, nilvadipine enhanced A clearance across the 8 mg of nilvadipine or placebo daily for 78 weeks of treat- BBB. In addition to these properties, nilvadipine has ment. Patients will initially undergo a screening assess- fi shown ef cacy against a broad range of AD pathological ment to confirm eligibility. This will be followed by a τ mechanisms, including -phosphorylation, reduced cere- baseline visit (week 0), when each patient is randomised fl fl 3 bral blood ow and neuroin ammation. and will receive the first dose of study medication. Studies have found that nilvadipine is distributed Patients will then undergo assessments at weeks 6, 13, 26, extensively throughout the body, including the brain 39, 52, 65 and 78 (±7 days) after beginning treatment. and has been shown to have a cerebrocirculatory enhan- fi 4 A nal follow-up assessment will be undertaken at cing effect. Nilvadipine has also been shown to protect 82 weeks (study end point). low-density lipoprotein cholesterol from in vivo oxidation in patients with hypertension with high risk of athero- sclerosis and to inhibit the generation of cytokines Inclusion/exclusion criteria derived from activated T lymphocytes in collagen Patients diagnosed with mild-to-moderate AD based on 56 disease complicated with essential hypertension. the National Institute of Neurological and Communicative Several epidemiological studies with different calcium Disorders and Stroke/Alzheimer’s disease and Related channel antagonists have been conducted to determine Disorders Association, Inc (NINCDS-ADRDA) criteria are their potential usefulness in the management of AD. In suitable for treatment with nilvadipine.12 See box 1 for the Systolic Hypertension in Europe (Syst-Eur) trial, details of study inclusion and exclusion criteria. which involved active treatment with the DHP CCB nitrendipine in over 2400 patients, there was a 55% reduction in the incidence of AD.7 The Baltimore Randomisation and blinding Longitudinal Study of Ageing also found a strong trend To prevent the introduction of bias, randomisation will be towards reduced relative risk of AD in patients treated via an online system, accessed via http://www.ctu.co.uk, with DHP CCBs, with no lowered risk observed in the hosted by the Clinical Trials Unit (CTU), King’s College non-DHP CCB treatment group.8 London (KCL). Eligible participants will be randomised to Furthermore, nilvadipine has been shown to have either the nilvadipine or placebo treatment group. The favourable effects on cognitive function with stabilisation nilvadipine capsules and placebo capsules will be pack- of cognitive decline and reduced conversion to AD in aged and labelled identically. Randomisation will be at the patients with hypertension with mild cognitive impair- level of the individual patient, using block randomisation ment.9 A study by Kennelly et al10 provided preliminary with randomly varying block sizes and stratified by country evidence suggesting the potential efficacy in the treat- site. Once the patient has been randomised, the online ment of AD. A 6-week open label study demonstrated system will automatically recognise which treatment packs that nilvadipine was well tolerated in patients with AD.11 are located in each study pharmacy at the recruiting study A nilvadipine slow release 8 mg formulation did not site and will randomly select a pack in the appropriate trial reduce blood pressure (BP) in non-hypertensive patients arm to be dispensed to the patient. All study staff at all with AD, but appropriately lowered BP in hypertensive sites will be blinded to treatment allocation and will cases. No patient started on nilvadipine requested or remain blind until the end of the trial.