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LLY's Retatrutide Nears 2027 Filing With Two More Phase III Wins

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Key Takeaways

  • LLY's TRIUMPH-2 study showed retatrutide drove up to 20.8% weight loss and A1C reductions at 80 weeks.
  • TRIUMPH-3 showed LLY's retatrutide delivered up to 22.6% weight loss in severe obesity at 80 weeks.
  • LLY said the latest data will support filings for retatrutide in the United States in Q1 2027.

Eli Lilly (LLY - Free Report) announced positive top-line data from two late-stage studies evaluating its next-generation, experimental triple-acting incretin, retatrutide, in patients with obesity or those who are overweight as well as some of its most serious complications – type II diabetes and established cardiovascular disease.

The phase III TRIUMPH-2 study is under a basket design evaluating the safety and efficacy of once weekly retatrutide versus placebo in participants with type II diabetes and obesity or those who are overweight. Patients in the study were randomized in a 1:1:1:1 ratio to receive retatrutide (4 mg, 9 mg, 12 mg) or placebo over a period of 80 weeks.

Meanwhile, the phase III TRIUMPH-3 study is evaluating the safety and efficacy of once-weekly retatrutide versus placebo in participants with severe obesity and established cardiovascular disease. Patients in this study were randomized in a 1:1:2 ratio to receive retatrutide 9 mg, 12 mg, or placebo over a period of 80 weeks.

Year to date, Lilly’s shares have risen 10.7% compared with the industry’s 11.8% rally.

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LLY’s Retatrutide Scores Big in Latest Obesity Studies

Data from the TRIUMPH-2 study showed that treatment with all doses of retatrutide (4 mg, 9 mg, 12 mg) led to substantial weight loss and improved glycemic control at 80 weeks in adults with type II diabetes and obesity or overweight. Treatment with retatrutide 4 mg, 9 mg, and 12 mg led to an average weight loss of 29.8 lbs (12.7%), 45.4 lbs (19.1%), and 49.6 lbs (20.8%), respectively, in the given patient population, at 80 weeks.

Data from the TRIUMPH-3 study showed that treatment with retatrutide (9 mg, 12 mg) led to an average weight loss of up to 55.8 lbs (22.6%) at 80 weeks in patients with severe obesity and established cardiovascular disease.

Importantly, treatment with retatrutide meaningfully reduced certain cardiovascular risk factors, with the highest dose (12mg) delivering average reductions of 37% in triglycerides, 16.5% in non-HDL cholesterol, 9.3 mmHg in systolic blood pressure, 7.5 in (19.0 cm) in waist circumference, and 51.2% in high-sensitivity C-reactive protein (hsCRP) in the TRIUMPH-3 study.

LLY’s Previous Phase III Wins With Retatrutide

We remind investors that the success of the phase III TRIUMPH-2 and TRIUMPH-3 obesity studies marks the fourth and fifth positive phase III data readout for Eli Lilly’s retatrutide.

In May 2026, Lilly announced that the phase III TRIUMPH-1 study, which evaluated the efficacy and safety of three doses (4 mg, 9 mg and 12 mg) of retatrutide for 80 weeks against placebo in adults with obesity or overweight, met its primary endpoint.

In March 2026, Eli Lilly reported that the late-stage TRANSCEND-T2D-1 study of once-weekly retatrutide in adults with T2D and inadequate glycemic control met its primary endpoint.

In late 2025, Eli Lilly reported meeting all primary and key secondary endpoints in the late-stage TRIUMPH-4 study, which evaluated the candidate in adults with obesity or overweight and knee osteoarthritis, without diabetes.

Retatrutide is being evaluated in several phase III studies for obesity and overweight with at least one weight-related medical problem, T2D, knee osteoarthritis pain, moderate-to-severe obstructive sleep apnea (OSA), chronic low back pain, cardiovascular and renal outcomes and metabolic dysfunction-associated steatotic liver disease.

Importantly, with the latest results from the TRIUMPH-2 and TRIUMPH-3 studies, Lilly now has the data package that will support global regulatory filings for retatrutide as a potential treatment for obesity, knee osteoarthritis pain and OSA.

The company plans to submit a biologics license application for retatrutide to the FDA in the first quarter of 2027. However, the timeline seems a little delayed from the prior expectation of filing retatrutide for obesity and knee osteoarthritis pain in 2026. If approved, retatrutide could become another multibillion-dollar product.

Retatrutide represents a new generation of “triple-action” therapy targeting three biological pathways — GLP-1, GIP and glucagon — potentially offering greater weight-loss and metabolic benefits than existing medicines, which mostly act on one or two biological pathways. LLY’s approved obesity drug Zepbound targets GLP-1 and GIP, while Novo Nordisk’s (NVO - Free Report) blockbuster obesity drug Wegovy activates only GLP-1.

LLY’s Competition in the Obesity Space

Eli Lilly and Novo Nordisk presently dominate the obesity market.

Novo Nordisk gained approval for an oral version of its obesity drug, Wegovy, in December 2025 and launched the pill in January 2026. In early April 2026, Lilly gained FDA approval for its once-daily oral GLP-1 pill Foundayo (orforglipron) for treating obesity.

Smaller biotech firms, like Viking Therapeutics (VKTX - Free Report) and Structure Therapeutics (GPCR - Free Report) , are also advancing GLP-1–based therapies to challenge the incumbents. Viking Therapeutics’ dual GIPR/GLP-1 receptor agonist, VK2735, is being developed as both oral and subcutaneous formulations for the treatment of obesity. Viking Therapeutics plans to advance oral VK2735 into phase III development for obesity in the fourth quarter of 2026.

Structure Therapeutics’ phase II ACCESS study on its orally administered GLP-1 RA, aleniglipron, demonstrated significant weight loss across all doses. Structure Therapeutics expects to initiate the late-stage program of aleniglipron in obesity in the second half of 2026.

LLY’s Zacks Rank

Eli Lilly currently carries a Zacks Rank #3 (Hold). You can see the complete list of today’s Zacks #1 Rank (Strong Buy) stocks here.

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