AZP-531

Because of its orexigenic, adipogenic and diabetogenic activities, acylated ghrelin (AG) has emerged as an attractive target for the treatment of obesity and type 2 diabetes. Pharmacological tools have been designed in order to antagonize or block the hormone's activity, or inhibit ghrelin O-acyltransferase (GOAT), the enzyme that catalyzes its acylation. AG antagonists, shown to be potent inhibitors of growth hormone (GH) secretion, were not able to consistently induce the desirable metabolic effects. Some of them, on the contrary, acted as AG agonists. Similarly, AG-blocking agents including Spiegelmers, vaccines, and monoclonal antibodies, gave mixed results. More encouraging yet very preliminary data were obtained with a novel GOAT inhibitor. However, although significant, the observed decrease in circulating AG levels was partial and improvement work remains to be done. Unacylated ghrelin (UAG) and analogs were shown to potently and rapidly inhibit plasma AG levels, and to improve glucose metabolism in addition to displaying beneficial effects on a variety of cells. These data support the rationale for further development of this new therapeutic class in type 2 diabetes and the Prader-Willi syndrome.

AIM: ;To explore the safety, pharmacokinetics and pharmacodynamics in humans of the unacylated ghrelin analogue AZP-531, designed to improve glycaemic control and reduce weight.;METHODS: ;Assessments, including glucose measurements, were performed in a three-part randomized study. In Part A, healthy subjects [n = 44, age 18-50 years, body mass index (BMI) 20-28 kg/m(2) ] received a single subcutaneous dose of 0.3, 3, 15, 30, 60 or 120 µg/kg AZP-531 or placebo. In Part B, overweight/obese subjects (n = 32, age 18-65 years, BMI 28-38 kg/m(2) ) and in Part C, patients with type 2 diabetes [T2D; n = 36, age 18-65 years, BMI 20-40 kg/m(2) , glycated haemoglobin (HbA1c) 7-10%] received AZP-531 or placebo for 14 days (daily doses of 3, 15, 30 or 60 µg/kg and 15, 2 × 30 or 60 µg/kg, respectively).;RESULTS: ;AZP-531 was well tolerated. Single- and multiple-dose pharmokinetic variables were similar. Maximum AZP-531 concentrations were typically reached at 1 h post-dose. Observed maximum concentration (Cmax ) and area under the curve were dose-proportional. The mean terminal half-life (t1/2 ) was 2-3 h. In Part B, AZP-531 doses of ≥15 µg/kg significantly improved glucose concentrations, without increasing insulin levels, suggesting an insulin-sensitizing effect.

CONTEXT AND OBJECTIVE: ;Prader-Willi syndrome (PWS) is characterized by early-onset hyperphagia and increased circulating levels of the orexigenic Acylated Ghrelin (AG) hormone with a relative deficit of Unacylated Ghrelin (UAG). AZP-531, a first-in-class UAG analog, was shown to inhibit the orexigenic effect of AG in animals, to improve glycemic control and decrease body weight in humans. We aimed to investigate the safety and efficacy of AZP-531 in patients with PWS for whom no approved treatment for hyperphagia is currently available.;METHODS AND DESIGN: ;Multi-center, randomized, double-blind, placebo-controlled trial. Forty-seven patients with genetically confirmed PWS and evidence of hyperphagia received daily subcutaneous injections of AZP-531 (3 and 4 mg for 50-70 kg and >70 kg body weight, respectively) or matching placebo for 14 days. Assessments included adverse events, vital signs, safety laboratory tests, the Hyperphagia Questionnaire (HQ), patient-reported appetite, body composition and glycemic measures.;RESULTS: ;AZP-531 was well tolerated. There was a significant improvement with AZP-531 versus placebo in the mean total score, the 9-item score and the severity domain score of the HQ (p < .