Sixteen obesity challengers sit in Phase 3 as Lilly and Novo keep the market into 2027

The pipeline behind the obesity market has grown crowded. It has not grown fast. Sixteen experimental obesity treatments from companies other than Eli Lilly and Novo Nordisk are in Phase 3 testing, and none is scheduled to report results before 2027 ^[1][2].

Recruiting Phase 3 obesity programs in the United States as of September 2026 include aleniglipron in the ACCOMPLISH-1 and ACCOMPLISH-2 trials, eloralintide across five ENLIGHTEN trials, enicepatide in three trials, elecoglipron in nine, AstraZeneca's AZD6234 in three SELENE trials, ribupatide in three KaiNETIC trials, berobenatide, and ASC30 in the AURORA-1 and AURORA-2 trials, along with several MariTide outcomes and extension studies ^[1][2].

Timing is the constraint. The earliest primary completion dates for these programs cluster in 2028, with MariTide the nearest exception at January 2027 ^[2]. Analysts at William Blair expect AstraZeneca's elecoglipron Phase 3 readouts in 2027 or 2028 ^[1]. Viking Therapeutics' VANQUISH-1 trial of subcutaneous VK2735, which enrolled about 4,650 patients for 78 weeks, is expected to report topline results in late 2027 ^[2].

The commercial picture explains why the crowding matters. Obesity therapeutics recorded $66 billion in sales last year and could reach between $105 billion and $200 billion by 2027 and beyond, according to IQVIA ^[1]. Lilly reported $23.0 billion in second-quarter 2026 revenue, up 48%, with Mounjaro at $9.9 billion (up 91%) and US Zepbound sales of $4.9 billion (up 44%); its oral orforglipron, sold as Foundayo, recorded $98 million in its first full quarter ^[2]. Novo Nordisk's Wegovy pill held about 90% of weekly oral obesity prescriptions as of July, or roughly 1.5 million people, according to William Blair ^[1].

On the leader side, Novo's CagriSema — a combination of cagrilintide and semaglutide — produced about 22.7% weight loss in trials, short of the roughly 25% the company had hoped for ^[2]. An FDA decision on CagriSema is expected in the fourth quarter of 2026 ^[1][2].

Why it matters for patients

Because no challenger is scheduled to produce Phase 3 results before 2027, the molecules available in US pharmacies are unlikely to change much in the near term. Prescriptions remain centered on semaglutide (Ozempic, Wegovy and Rybelsus) and tirzepatide (Mounjaro and Zepbound), plus two oral options already approved: orforglipron, sold as Foundayo, and oral semaglutide, sold as the Wegovy pill ^[2].

What may change sooner is who pays. The temporary Medicare GLP-1 Bridge program began in July 2026 and could expand coverage by an estimated 35%, reaching around 20 million potential patients, according to William Blair ^[1]. Coverage, pricing and formulary placement have moved faster than the pipeline.

Challengers also differ in ways that go beyond weight loss. Roche's enicepatide produced 22.5% weight loss after nearly a year in a Phase 2 study of people with obesity, and Zealand Pharma's petrelintide has shown less weight loss — up to 10.7% at 42 weeks — with what the companies describe as placebo-like tolerability ^[1][2]. Whether tolerability or higher efficacy matters more to patients will not be settled until late-stage data arrive. No head-to-head comparisons of these candidates against approved drugs have been reported.

What happens next

• Novo Nordisk is expected to start Phase 3 trials of oral zenagamtide and high-dose cagrilintide by the end of 2026 ^[1].
• An FDA decision on CagriSema is expected in the fourth quarter of 2026 ^[1][2].
• Structure Therapeutics is expected to start a registrational Phase 3 program for aleniglipron in the third quarter of 2026 ^[2].
• Amgen's MariTide has primary completion dates in January 2027; its MARITIME Phase 3 runs 72 weeks ^[2].
• Lilly has guided a regulatory filing for retatrutide in obesity and overweight to the first quarter of 2027 ^[1][2].
• Viking's VANQUISH-1 topline results are expected in late 2027 ^[2].