Safety, tolerability, pharmacokinetics, and pharmacodynamics of the first-in-class GLP-1 and amylin receptor agonist, amycretin: a first-in-human, phase 1, double-blind, randomised, placebo-controlled trial

Background

GLP-1 receptor agonists and amylin receptor agonists have shown clinically relevant weight loss and glucose-lowering effects in people with overweight, obesity, and type 2 diabetes. Amycretin is a novel, single-molecule GLP-1 receptor and amylin receptor agonist. We aimed to investigate the safety, tolerability, pharmacokinetic properties, and pharmacodynamic effects of single ascending doses (part A) and multiple ascending doses (parts B and C/D) of amycretin in adult participants with overweight or obesity.

Methods

In this phase 1, first-in-human, randomised, double-blind, placebo-controlled multipart study, participants were recruited at a single clinical research unit in San Antonio (TX, USA). Eligible individuals were men or women (including women of childbearing potential) aged 18–55 years at the time of signing informed consent with a BMI of 25·0–34·9 kg/m² for parts A and B and a BMI of 27·0–39·9 kg/m² for part C/D. For part A, participants were randomly assigned across six treatment groups (single ascending doses of oral amycretin [1 mg, 3 mg, 6 mg, 12 mg, 18 mg (12 + 6 mg per adaptive study design), or 25 mg]) or placebo (6:2 to amycretin groups vs placebo). Part A consisted of a 28-day screening period, a 1-day (single dose) intervention period, and a 21-day follow-up period. In part B, participants were randomly assigned across three treatment groups (multiple ascending doses of oral amycretin [3 mg, 6 mg, or 12 mg once daily]) or placebo (9:3 to amycretin groups vs placebo). Part B consisted of a 28-day screening period, a 10-day intervention period, and a 21-day follow-up period. In part C/D, 60 participants were randomly assigned to one of three dose-escalation treatment groups (multiple ascending doses of oral amycretin in a fixed titration regimen for all participants [part C1: from 3 mg to 50 mg once daily; part C2: from 6 mg to 2 × 50 mg (two tablets in a single daily dose); and part D: from 3 mg to 2 × 25 mg (two tablets in a single daily dose)]), or placebo (16:4 to amycretin groups vs placebo). Part C/D consisted of a 4-week screening period, a 12-week intervention period, and a 3-week follow-up period. The primary endpoint was the number of treatment-emergent adverse events reported from before dosing on day 1 (baseline) until the end-of-study visit on day 22 (part A), day 31 (part B), or day 105 (part C/D). Supportive secondary pharmacokinetic endpoints for parts A–D were area under the amycretin plasma concentration–time curve and maximum plasma concentration. Exploratory pharmacodynamic endpoints in part C/D were change in bodyweight (%) and fasting plasma glucose (mmol/L) from before dosing on day 1 until day 85. The safety analysis set, comprising all participants who were exposed to treatment, was used to analyse the endpoints and assessments related to safety. The full analysis set, comprising all randomly assigned participants, was used to analyse endpoints related to pharmacokinetic and exploratory pharmacodynamic endpoints. This study is registered with ClinicalTrials.gov, NCT05369390.

Findings

Between May 11, 2022, and Jan 9, 2024, 144 participants were enrolled in the study (48 participants in part A, 36 participants in part B, and 60 participants in part C/D). Across parts A–D, there were 364 treatment-emergent adverse events in 89 (62%) of 144 participants, all of which were mild or moderate in severity and increased in frequency in a dose-dependent manner. The most common treatment-emergent adverse events were gastrointestinal in nature (180 [49%] of 364 events), observed in 72 (81%) of 89 participants who reported a treatment-emergent adverse event. No deaths were reported. Amycretin plasma concentrations were consistent with dose proportionality across all treatment groups.

Interpretation

In people with overweight or obesity, amycretin appeared safe and tolerable. Results from this first-in-human, phase 1 study support further investigation of the weight loss properties of amycretin.

Funding

Novo Nordisk A/S.