The weight loss drug market has exploded over the past few years, with pharmaceutical giants racing to develop treatments that not only help people shed pounds but keep them off. The real challenge in obesity treatment isn't just losing weight—it's maintaining that loss over time. Now Eli Lilly and Co (LLY) has released data suggesting its experimental oral drug might solve a key piece of that puzzle.
On Thursday, Eli Lilly shared topline results from the ATTAIN-MAINTAIN Phase 3 trial of orforglipron, an oral medication designed to help patients maintain weight loss after using popular injectable treatments. The study looked at whether people could successfully switch from Novo Nordisk A/S (NVO) Wegovy (semaglutide) or Zepbound (tirzepatide) to this once-daily pill without regaining weight.
How The Study Worked
The trial enrolled participants from the earlier SURMOUNT-5 study who had already been taking the highest tolerated doses of either Wegovy or Zepbound for 72 weeks and had reached a weight plateau. These patients were then re-randomized to receive either orforglipron or placebo for 52 weeks, all while maintaining a healthy diet and exercise routine.
The results? Orforglipron hit its primary endpoint and all key secondary endpoints, demonstrating superior weight maintenance compared to placebo.
The Numbers Tell The Story
At 52 weeks, patients who switched from Wegovy to orforglipron maintained their previous weight loss with an average difference of just 0.9 kg. Those transitioning from Zepbound maintained their weight loss with an average difference of 5.0 kg.
The picture becomes even clearer when you look at the 24-week post-hoc analysis. Patients switching from Wegovy to orforglipron saw their weight change by only 0.1 kg from baseline, while those on placebo gained 9.4 kg. Similarly, patients moving from Zepbound to orforglipron gained 2.6 kg compared to 9.1 kg for the placebo group.
Translation: The oral pill did a significantly better job preventing weight regain than no treatment at all.
Safety Profile Looks Solid
The safety and tolerability profile of orforglipron aligned with what researchers saw in previous Phase 3 studies. Most adverse events were gastrointestinal-related and generally mild to moderate in severity—the typical side effects you'd expect from this class of drugs.
Discontinuation rates due to adverse events were relatively low across all groups: 4.8% for patients switching from Wegovy to orforglipron, 7.6% for the Wegovy-to-placebo group, 7.2% for those moving from Zepbound to orforglipron, and 6.3% for the Zepbound-to-placebo cohort.
Importantly, researchers observed no hepatic safety signal—good news considering liver function has been a concern with some obesity medications.
Building On Earlier Success
This maintenance data comes on the heels of promising results from the ATTAIN-1 trial, where all three doses of orforglipron (6 mg, 12 mg, and 36 mg) met the primary endpoint of superior body weight reduction compared to placebo at 72 weeks.
The big picture here is that Eli Lilly is building a case for orforglipron as both an effective weight loss treatment and a maintenance therapy—potentially giving patients more flexibility in how they manage their obesity long-term. The oral format is a particular advantage over injections, which many patients find burdensome or intimidating.
As pharmaceutical companies continue investing heavily in obesity treatments to meet surging demand, the focus has shifted toward long-term sustainability. Helping patients lose weight is only half the battle; preventing regain is where the real value lies.
LLY Price Action: Eli Lilly shares were up 2.20% at $1,064.73 at the time of publication on Thursday. The stock is approaching its 52-week high of $1,111.99.
