The Obesity Pipeline Has 951 Trials and One Clear Leader

The numbers

Right now there are 951 clinical trials tagged with obesity or overweight conditions on ClinicalTrials.gov. Of those, 338 are actively recruiting patients and 92 are in Phase 3.

But the headline number hides the real story. When you break it down by sponsor, the obesity pipeline isn't a crowded field of equals. It's one company running away with it.

Lilly vs. Novo: it's not even close

Eli Lilly has 26 actively recruiting obesity trials right now, including 15 in Phase 3. Novo Nordisk, the company that created the GLP-1 category with semaglutide, has 6 recruiting trials with 2 in Phase 3.

That's a 4:1 ratio in recruiting trials and a 7.5:1 ratio in Phase 3 studies. By total trial count (including completed and not-yet-recruiting), Lilly has 45 obesity trials to Novo's 43. They're nearly tied historically. But Lilly's active pipeline is dramatically larger.

Novo's smaller active footprint is partly strategic. They've already commercialized semaglutide across multiple formulations and indications. Many of their earlier trials have completed. But the gap in Phase 3 recruiting studies suggests Lilly is investing more aggressively in the next wave of obesity therapies.

The rest of the field

Beyond the big two, the obesity pipeline includes 87 industry sponsors. Most have small programs, but several are building serious competitive positions.

A few things jump out from this table.

Kailera, a VC-backed startup that licensed its pipeline from China's Hengrui Pharmaceuticals (MedCity News, Oct 2024), has 3 Phase 3 trials recruiting. They're developing oral incretin-based therapies, which could disrupt the injectable-dominated market if the efficacy holds up.

Pfizer re-entered obesity by acquiring Metsera in a deal valued at roughly $10 billion (Pfizer, 2025), giving them 2 recruiting trials. Pfizer had previously discontinued their oral GLP-1 candidate danuglipron after liver safety concerns and high discontinuation rates (STAT News, Apr 2025). The Metsera acquisition represents their second run at the category.

Alnylam is taking a completely different approach with RNA interference. Their 2 Phase 2 trials represent a non-GLP-1 mechanism of action that could matter if the market gets saturated with incretin-based therapies.

What BD teams should be watching

If you work in biotech business development or competitive intelligence, here's what this data suggests:

• The oral incretin race is the next battleground. Kailera (with Hengrui-licensed assets), several Chinese biotechs, and others are pursuing oral formulations. Whoever gets there first with equivalent efficacy to injectables will have a massive commercial advantage. Watch for Phase 2 readouts.
• Non-GLP-1 mechanisms are the contrarian bet. Alnylam's RNAi approach, Regeneron's antibody programs, and academic research into gut-brain signaling are all early but could create differentiated second-generation therapies. If you're a mid-size biotech looking for a partnering angle, this is where the white space is.
• Combination therapies are everywhere. A significant chunk of Lilly's 26 recruiting trials are studying tirzepatide in combination with other agents or in new patient populations (heart failure, sleep apnea, NASH). The playbook isn't just "better weight loss." It's "weight loss plus cardiovascular outcomes" or "weight loss plus metabolic liver disease."
• The NIDDK is the biggest non-industry player. With 25 trials, the National Institute of Diabetes and Digestive and Kidney Diseases is running more obesity trials than Novo Nordisk. Academic and government-funded research often generates licensing opportunities for companies looking to build an obesity franchise without starting from scratch.