Retatrutide for obesity — phase 2 trial
New England Journal of Medicine
TL;DR
Retatrutide produced large dose-dependent weight loss in a 338-person phase 2 obesity trial, reaching a mean 24.2% reduction at 48 weeks in the 12 mg group.
Phase 2 · randomized · double-blind · placebo-controlled · 338 adults
What was studied
The question.
Whether once-weekly retatrutide, a GIP/GLP-1/glucagon receptor agonist, could reduce body weight in adults with obesity or overweight plus a weight-related condition.
How it was conducted
The study design.
Adults without diabetes were randomized across several weekly retatrutide dose groups or placebo for 48 weeks. Everyone also received lifestyle counseling. The main outcome was percentage change in body weight, with safety and cardiometabolic measures also followed.
What it found
Did it actually work?
- Mean weight loss at 48 weeks ranged from 8.7% at 1 mg to 24.2% at 12 mg, versus 2.1% with placebo.
- At 12 mg, 83% of participants lost at least 15% of baseline body weight.
- Gastrointestinal side effects were the most common and were dose-related.
Why it matters
How to read this result.
This was the study that established retatrutide as one of the most promising next-generation incretin-based obesity drugs and justified the larger phase 3 programme.
Keep in mind
What the study does not prove.
- This was a phase 2 trial, not an approval study.
- The study was funded by Eli Lilly.
- Longer-term efficacy and safety require larger and longer trials.
Original source
Want to read the original?
We summarize the study here first. The original source is there when you want the full methods, statistics, tables and author discussion.
Open ClinicalTrials.gov record