EV0643 Contact information: A phase I, 3-part placebo-controlled randomised trial to evaluate the safety, Seamus O’Brien AstraZeneca Research & Development Macclesfield, Cheshire, UK tolerability and of - in healthy subjects [email protected] Timi Edeki1, Diansong Zhou2, Frans van den Berg3, Helen Broadhurst4, William C. Holmes5, Gary Peters3, Maria Sunzel6, Seamus O’Brien4 1AstraZeneca, Wilmington, DE, USA; 2AstraZeneca, Waltham, MA, USA; 3Hammersmith Medicines Research, London, UK; 4AstraZeneca, Macclesfield, UK; 5AstraZeneca, Gaithersburg, MD, USA; 6Contractor at AstraZeneca, Wilmington, DE, USA

Background Table 1. Subjects’ baseline characteristics Figure 1. Geometric mean (A) aztreonam and (B) avibactam concentration-time profiles in Part A following individual and combined administration of aztreonam 2000 mg and avibactam 600 mg by 1-h IV infusion Part A Part B Part C • The emergence and global dissemination of metallo-β-lactamase (MBL)-producing (A) (B) Enterobacteriaceae, including NDM-type and VIM-type, which are resistant to , Active Placebo Active Placebo Active Placebo 100 Aztreonam 2000 mg alone (n=7) 100 Avibactam 600 mg alone (n=8) represents an urgent threat to human health for which few treatment options currently exist.1, 2 (n=8) (n=4) (n=40) (n=16) (n=18) (n=6) Aztreonam-avibactam 2000-600 mg (n=7) Aztreonam-avibactam 2000-600 mg (n=7) • Aztreonam, a β-lactam, is stable to Ambler class B MBLs including NDM-type and Mean (SD) age, years 31 (7) 34 (7) 30 (7) 27 (5) 49 (19) 51 (19) VIM-type. However, bacteria that express MBLs frequently co-express other classes of β-lactamase Sex, n (%): Female 0 0 0 0 2 (11.1) 1 (16.7) that will hydrolyse aztreonam. 10 10 Male 8 (100.0) 4 (100.0) 40 (100.0) 16 (100.0) 16 (88.9) 5 (83.5) Avibactam is a novel non-β-lactam β-lactamase inhibitor with in vitro activity against many serine • Race: Asian 2 (25.0) 0 3 (7.5) 2 (12.5) 1 (5.6) 0 β-lactamases including Ambler class A (e.g. extended-spectrum-β-lactamase and Klebsiella Black 1 (12.5) 1 (25.0) 8 (20.0) 2 (12.5) 1 (5.6) 1 (16.7) pneumoniae carbapenemase [KPC]), class C (e.g. AmpC), and some class D enzymes, but not 1 1 class B MBLs.3-5 White 5 (62.5) 3 (75.0) 27 (67.5) 11 (68.8) 16 (88.9) 5 (83.3) • The combination of aztreonam plus avibactam has the potential to treat infections caused by Other 0 0 2 (5.0) 1 (6.3) 0 0 Enterobacteriaceae producing both MBLs and serine and β-lactamases as has been demonstrated Mean (SD) BMI, kg/m2 23.4 (2.6) 24.3 (4.6) 24.0 (2.5) 23.8 (2.2) 24.5 (2.6) 25.0 (3.1) by in vitro and in vivo evaluation of the efficacy of the combination.6-9 0.1 0.1 BMI, body mass index – The combination of ceftazidime-avibactam was approved in 2015 by the US FDA for the treatment Plasma avibactam concentration (µg/mL) of complicated intra-abdominal (in combination with metronidazole) and complicated urinary tract Plasma aztreonam concentration (µg/mL) 10 infections in patients with no or limited alternative treatment options; an application for approval 0.01 0.01 in the European Union has been submitted. • In addition to the three discontinuations due to abnormal liver function tests in Part B, a further six 0 4 8 12 16 20 24 0 4 8 12 16 20 24 subjects in Part B (Cohort 2, n=2; Cohort 3, n=4) had AEs of abnormal liver function tests or The ceftazidime-avibactam clinical development programme has established that avibactam has Nominal time (h) Nominal time (h) • transaminase increased that did not lead to study discontinuation. Cohort 2 was halted after four limited potential for drug–drug interactions11 and ceftazidime-avibactam has a safety profile 12, 13 subjects had received aztreonam-avibactam because of the abnormal liver function test AEs. consistent with administration of ceftazidime alone. However, avibactam in combination with Table 3. Geometric mean (%CV) plasma and urinary aztreonam and avibactam PK parameters after single doses of aztreonam, avibactam and aztreonam-avibactam aztreonam has not previously been administered to humans. – Abnormal liver function test and transaminase elevations are consistent with the known safety Part A Part B Part C This Phase I ‘first-in-man’ randomised trial assessed the safety, tolerability and pharmacokinetics profile of aztreonam monotherapy.14 • Aztreonam-avibactam Aztreonam Avibactam Aztreonam- Cohort 1 Cohort 2 Cohort 3 Cohort 4 Cohort 5 Young cohort Elderly cohort (PK) of single and multiple doses of aztreonam-avibactam in healthy adult subjects. – The aztreonam-avibactam dose reductions implemented in Part B Cohorts 4 and 5, and further dosage group/cohort 2000 mg 600 mg avibactam 2000-375 mg 2000-600 mg 1500-600 mg 1500-450 mg 1500-410 mg 2000-546.7 mg 2000-546.7 mg modified in Part C with the addition of a loading dose, were associated with a reduced incidence (n=7) (n=7) 2000-600 mg (n=8) (n=4) (n=8) (n=10) (n=10) (n=10) (n=8) (n=7) of liver enzyme abnormalities (elevation of AST ≥2 x ULN was observed for one subject in Part C, but was not reported as an AE). Infusion duration, h 1 1 1 1 1 2 3 3 3 3 Aztreonam All of the hepatic enzyme abnormalities were asymptomatic, transient and reversible. No other Methods • AUC, μg.h/mL 372 (15) – 375 (13) 345 (16) 326 (6) 283 (18) 270 (10) 250 (13) – – This Phase I, randomised, double-blind, 3-part trial (NCT01689207) was conducted at Hammersmith laboratory abnormalities or clinical symptoms attributable to hepatic disorder were observed • AUC0–6h, μg.h/mL 325 (13) – 325 (10) 299 (15) 286 (5) 245 (15) 222 (9) 205 (13) 276 (14) 308 (12) Medicines Research, London, UK. (i.e. there were no other liver-related AEs). Cmax, μg/mL 143 (14) – 137 (11) 123 (17) 123 (6) 82 (16) 63 (9) 59 (13) 76 (14) 82 (12) • Population PK models, developed using aztreonam data from the literature and avibactam from the The most frequently reported AEs by system organ class were: ceftazidime-avibactam database, taking into account variability in patients, were used to calculate • CLr, L/h 3.9 (19) – 3.8 (18) 4.0 (14) 4.1 (7) 4.2 (14) 4.1 (22) 4.4 (12) 4.2 (17) 3.4 (17) † † probability of target attainment (PTA) against pharmacodynamic targets established from – Part A: metabolism and nutrition disorders in one subject (12.5%) and nervous system disorders Ae (0–24h), mg 1440 (7) – 1400 (8) 1380 (8) 1310 (3) 1170 (9) 1080 (19) 1090 (7) 1160 (7) 1050 (12) 9 in one subject (12.5%) on active treatment; and general disorders and administration site † † preclinical data. fe (0–24h), % 72.1 (7) – 70.2 (9) 69.2 (8) 65.7 (2) 77.8 (9) 72.2 (19) 72.7 (7) 58.1 (7) 52.4 (12) conditions in one subject (25.0%) and vascular disorders in one subject (25.0%) on placebo • Dose selection for Part A was based on targets established from preclinical data i.e. predicted Avibactam achievement of free concentrations of aztreonam and avibactam that are maintained for at least 60% – Part B: investigations in 10 subjects (17.9%) on active treatment (none on placebo) and AUC, μg.h/mL – 53 (23) 58 (18) 32 (13) 48 (13) 53 (13) 36 (12) 31 (15) – – fT> MIC of 8 mg/L for aztreonam and 50% fT> CT 2.5 mg/L for avibactam in at least 90% of patients. gastrointestinal disorders in seven subjects (12.5%) on active treatment (none on placebo) AUC0–6h, μg.h/mL – 49 (21) 54 (16) 29 (12) 45 (12) 49 (13) 32 (11) 28 (14) 42 (17) 52 (11) Dosage regimens in Parts B and C were selected by a safety review committee following review of • – Part C: gastrointestinal disorders in seven subjects (29.2%) on active treatment (none on Cmax, μg/mL – 26.8 (14) 28.5 (15) 16.0 (10) 25.1 (6) 19.3 (16) 10.0 (11) 8.7 (14) 12.1 (18) 15.2 (14) safety (including liver function tests), tolerability and PK data, and were also informed by population CLr, L/h – 9.8 (22) 8.7 (17) 10.6 (19) 10.9 (13) 11.1 (12) 11.9 (25) 12.5 (16) 10.8 (16) 7.8 (28) PK-modelled pharmacodynamic target attainment predictions. placebo) and nervous system disorders in four subjects (22.2%) on active treatment and two subjects (33.3%) on placebo. Ae , mg – 513 (7) 507 (3) 336 (8) 519 (8) 586 (4) 423 (17) 388 (5) 453 (3)† 407 (21)† In Part A, subjects aged 18–45 years received single 1-h infusions of aztreonam 2000 mg, (0–24h) • † † avibactam 600 mg and aztreonam-avibactam 2000-600 mg (n=8) or matching placebo (n=4) by fe (0–24h), % – 85.5 (7) 84.5 (3) 89.7 (8) 86.5 (8) 97.6 (3) 94.1 (17) 94.7 (5) 82.8 (3) 74.4 (21)

randomised crossover, each separated by a ≥3 day washout period. Ae (0–24h), cumulative amount of drug collected in urine over 24 h; AUC0–6h, area under the concentration-time curve during the first 6 h; CLr, renal clearance; fe (0–24h), fraction of dose excreted unchanged in urine over 24 h † Table 2. Overview of AEs In Part C, urine was only collected up to the first 6 h after dosing; data shown are Ae (0–6h) / fe (0–6h) • In Part B, subjects aged 18–45 years received 11 days of aztreonam-avibactam (n=40) or matching placebo (n=16) every 6 h (q6h) on Days 2–10; single doses were administered on Days 1 and 11: Subjects, n (%) Part A Part B Part C Table 4. Geometric mean (%CV) plasma aztreonam and avibactam PK parameters after multiple doses of aztreonam-avibactam – Cohort 1: 2000-375 mg (n=8) 1-h infusion Active Placebo Active Placebo Active Placebo (n=8) (n=4) (n=40) (n=16) (n=18) (n=6) Part B (Day 11) Part C (Day 10) – Cohort 2: 2000-600 mg (n=4) 1-h infusion Aztreonam-avibactam Cohort 1 Cohort 2 Cohort 3 Cohort 4 Cohort 5 Young cohort Elderly cohort Any AE 2 (25.0) 1 (25.0) 23 (57.5) 3 (18.8) 12 (66.7) 3 (50.0) – Cohort 3: 1500-600 mg (n=8) 2-h infusion dosage group/cohort 2000-375 mg q6h (n=8) 2000-600 mg q6h (n=4) 1500-600 mg q6h (n=8) 1500-450 mg q6h (n=10) 1500-410 mg q6h (n=10) 1500-410 mg q6h (n=10) 1500-410 mg q6h (n=8) – Cohort 4: 1500-450 mg (n=10) 3-h infusion Any AE with outcome of death 0 0 0 0 0 0 Infusion duration, h 1 1 2 3 3 3 3 – Cohort 5: 1500-410 mg (n=10) 3-h infusion. Aztreonam Any SAE 0 0 0 0 0 1 (16.7) • In Part C, subjects received 10 days of aztreonam-avibactam (n=18) or matching placebo (n=6) AUCss, μg.h/mL 275 (14) – 231 (16) 223 (8) 203 (11) 211 (16) 259 (12) 2000-546.7 mg (30 min loading dose of 500-136.7 mg ATM-AVI plus 2.5 h maintenance infusion of AE leading to discontinuation RAUC 0.92 (9) – 0.94 (5) 1.00 (4) 0.99 (6) 0.77 (5) 0.84 (6) 1 (12.5) 0 3 (7.5) 0 0 1 (16.7) 1500-410 mg ATM-AVI) on Day 1, followed by 1500-410 mg (3-h infusions) q6h on of study treatment Cmax ss, μg/mL 124 (9) – 80.9 (13) 62.6 (9) 55.7 (9) 57 (15) 66 (13)

Days 2–9; single doses were administered on Day 10: RCmax 1.01 (14) – 0.97 (7) 0.99 (8) 0.94 (10) 0.76 (4) 0.81 (4) Subjects with multiple events in a single category are counted once for each category – Cohort 1: young subjects (aged 18–45 years) CLr, L/h 4.7 (19) – 4.9 (15) 5.1 (28) 5.3 (14) 5.0 (19) 4.0 (21) – Cohort 2 elderly subjects (aged ≥65 years). Avibactam • Blood and urine for PK analysis were collected at scheduled intervals. Pharmacokinetics AUCss, μg.h/mL 26 (13) – 43 (12) 29 (10) 27 (13) 29 (20) 39 (14) RAUC 0.89 (5) – 0.89 (6) 0.91 (5) 0.96 (12) 0.70 (6) 0.74 (6) In Part A, geometric mean plasma concentration-time profiles of aztreonam and avibactam after • Cmax ss, μg/mL 14.5 (16) – 17.6 (12) 8.7 (10) 8.4 (17) 8.9 (20) 11.6 (15) single 1-h IV infusions alone and in combination (Figure 1) showed that co-administration of both RCmax 0.91 (9) – 0.91 (8) 0.87 (8) 0.96 (14) 0.73 (8) 0.77 (10) drugs did not affect the profiles observed for either drug alone (i.e. there were no drug–drug CLr, L/h 12.4 (25) – 13.9 (12) 14.7 (25) 14.5 (15) 13.0 (22) 9.5 (19) interactions between aztreonam and avibactam). Results AUCss, area under the concentration-time curve during one dosing interval at steady state; Cmax ss, maximum concentration at steady state; RAUC, ratio of AUCss : AUC0–6h; RCmax ratio of Cmax ss : Cmax Subjects – Plasma PK parameters, renal clearance and % urinary excretion of both aztreonam and Subjects’ baseline characteristics are summarised in Table 1. avibactam were similar whether administered alone or in combination (Table 3). • References Safety and tolerability In Part B, linear PK was observed for both aztreonam and avibactam, with no accumulation • 1. Nordmann P et al. Emerg Infect Dis. 2011;17:1791–1798. 10. Actavis Inc. AVYCAZ (ceftazidime-avibactam) for injection, for following multiple dosing, as demonstrated by ratios of area under the concentration-time curve A summary of adverse events (AEs) and serious AEs (SAEs) reported throughout the trial is shown 2. Tangden T et al. J Intern Med. 2015;277:501–512. intravenous use: prescribing information. 2015. Available from: Conclusions 3. Lagace-Wiens P et al. Core Evid. 2014;9:13–25. http://pi.actavis.com/data_stream.asp?product_group=1957&p=pi& • (AUC) and maximum concentration (Cmax) at steady state and after single doses (Table 4). in Table 2. AEs leading to discontinuation of study treatment occurred in five subjects overall: • Single and multiple doses of aztreonam-avibactam were generally well-tolerated in healthy 4. Zhanel GG et al. Drugs. 2013;73:159–177. language=E. – Renal clearance accounted for the majority of plasma clearance; both drugs were predominantly 5. Lahiri SD et al. Antimicrob Agents Chemother. 2013;57:2496–2505. 11. Vishwanathan K et al. Drug Metab Dispos. 2014;42:932–942. – Part A: asymptomatic hyperamylasaemia (n=1) identified 3 days after treatment with avibactam adult subjects, and there was no evidence of drug–drug interactions. There were no SAEs in 6. Crandon JL et al. Antimicrob Agents Chemother. 2013;57:3299– 12. Carmeli Y et al. Lancet Infect Dis. 2016; In press. 600 mg excreted unchanged in urine. subjects randomised to aztreonam and/or avibactam. 3306. 13. Mazuski JE et al. Clin Infect Dis. 2016; doi: 10.1093/cid/ciw133. 7. Livermore DM et al. Antimicrob Agents Chemother. 14. E. R. Squibb & Sons Limited. Azactam 1g or 2g Powder for Solution – Part B: abnormal liver function test (i.e. alanine transaminase ≥3 x upper limit of normal [ULN] – There was no consistent association between liver enzyme elevations and exposure (AUC or • Liver enzyme elevations observed in Part B Cohorts 2 and 3 were minimised in later cohorts that 2011;55:390–394. for Injection or Infusion, vial. 2014. Available from: http://www. 8. Biedenbach DJ et al. Antimicrob Agents Chemother. medicines.org.uk/emc/medicine/549/SPC/Azactam+1g+or+2g+Pow Cmax) of aztreonam or avibactam in Part B. or [AST] ≥2 x ULN) in subjects treated with aztreonam-avibactam in employed lower doses of both the aztreonam and avibactam components and longer infusion 2015;59:4239–4248. der+for+Solution+for+Injection+or+Infusion,+vial. Cohort 2 (n=2) and Cohort 3 (n=1) considered related to the study treatment; none of these durations. 9. Singh R et al. J Antimicrob Chemother. 2015;70:2618–2626. • In Part C, aztreonam and avibactam exposure parameters (AUC and Cmax) were slightly higher in events were associated with clinically significant changes in alkaline phosphatase or total elderly subjects as compared with younger subjects, with the exception of aztreonam on Day 1, • Renal clearance represents the primary elimination route for both aztreonam and avibactam. bilirubin Disclosures which showed comparable exposure parameters in both cohorts (Tables 3 and 4). This is There was no evidence of accumulation of either drug following repeated administration. TE, DZ, HB, SO’B and WCH are employees and shareholders of AstraZeneca. FvdB and GP are employees of Hammersmith Medicines Research, – Part C: SAE of (n=1) in a subject treated with placebo. consistent with the normal decline in renal function in subjects with advancing age. which received institutional research grant funding from AstraZeneca for the conduct of the study. MS is a contractor for AstraZeneca.

This study was supported by AstraZeneca. Medical writing support was provided by Mark Waterlow of Prime Medica Ltd, Knutsford, Cheshire, UK, funded by AstraZeneca. Presented at the 26th European Congress of Clinical Microbiology and Infectious Diseases, 9–12 April 2016, Amsterdam, the Netherlands.