Eli Lilly Orforglipron Maintains Weight Loss
Eli Lilly orforglipron met maintenance endpoints and Lilly filed for FDA review, which could speed approval and alter commercial positioning.
KEY TAKEAWAYS
- Orforglipron met primary and all key secondary endpoints for weight maintenance at 52 weeks.
- Patients who switched from Wegovy maintained all but 0.9 kg of prior weight loss on average.
- Lilly filed for FDA review with a Commissioner's National Priority Voucher to accelerate the review timeline.
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On Dec. 18, 2025, Eli Lilly and Co. (LLY) reported that its oral candidate orforglipron helped patients sustain nearly all prior weight loss after switching from injectable GLP‑1 therapies in a Phase 3 study. The company said it has submitted the pill to the FDA for obesity treatment.
Orforglipron Trial Results and FDA Submission
Eli Lilly said in a press release that the ATTAIN-MAINTAIN trial was a 52-week, randomized, double-blind, placebo-controlled Phase 3 study involving 376 adults with obesity or overweight. These participants had completed 72 weeks on the highest tolerated dose of Wegovy (semaglutide) or Zepbound (tirzepatide) in the prior Surmount-5 trial. They were re-randomized 3:2 to receive either maximum-tolerated orforglipron or placebo alongside diet and exercise.
Orforglipron met the primary and all key secondary endpoints for weight maintenance compared with placebo at 52 weeks following prior weight loss on Wegovy or Zepbound. Participants who switched from Wegovy to orforglipron maintained all but 0.9 kilograms of their previously achieved weight loss on average.
Post-hoc analyses at 24 weeks showed that Wegovy switchers on orforglipron averaged a weight change of −0.2 pounds versus +20.7 pounds on placebo. Zepbound switchers on orforglipron gained 5.7 pounds compared with 20 pounds on placebo.
Adverse events were mostly mild to moderate gastrointestinal issues. Discontinuation rates due to adverse events were 4.8% for orforglipron among Wegovy switchers and 7.6% for placebo Wegovy switchers. Among Zepbound switchers, discontinuations were 7.2% for orforglipron and 6.3% for placebo. The company reported no hepatic safety signals.
The FDA submission carries a Commissioner's National Priority Voucher, which could shorten the standard review timeline. Analysts estimate an FDA decision as early as March 2026 or possibly by the end of 2025, a timing that will influence the drug’s commercial rollout.
Canadian Price Cuts and Commercial Context
On Dec. 17, 2025, Lilly notified pharmacies of price reductions of 20% or more for Mounjaro and Zepbound in Canada.
This pricing move coincides with growing Phase 3 evidence for orforglipron. The ATTAIN-2 trial showed 10.5% weight loss at 72 weeks versus 2.2% for placebo. The ACHIEVE-3 trial demonstrated a larger A1C reduction—1.9% versus 1.7%—and greater weight loss compared with oral semaglutide in people with type 2 diabetes.
Analysts expect the FDA action timeline to shape orforglipron’s competitive positioning and commercial launch strategy.
