Current leaders Eli Lilly and Novo Nordisk have cornered the early market for weight loss therapeutics, but several other players, large and small, are bidding for a piece of the potential $200 billion pie.
The obesity market has grown exponentially over the course of just a few years, with no signs of slowing as Big Pharma and biotech contenders vie for third place behind Eli Lilly and Novo Nordisk. This year has seen its share of action, with launches of oral offerings from both leaders and multiple clinical wins spanning the weight loss space. And it’s not over yet, as companies including Roche and AstraZeneca gear up for data readouts in the second half of 2026.
There’s good reason for all the interest. Obesity therapeutics hit $66 billion in sales last year and could skyrocket to between $105 billion and $200 billion by 2027 and beyond, according to IQVIA—leaving plenty of market share for these companies, as well as smaller players like Viking Therapeutics and Structure Therapeutics.
To cap off second quarter earnings season, investment banking group William Blair in a report last week painted a picture of recent advances and future inflection points to look out for in the obesity space.
Lilly grows prescription base for Foundayo
Current market leader Eli Lilly is setting records with its injectable GLP-1 tirzepatide products Mounjaro and Zepbound and continues to propel its commercial engine with the recently approved oral newcomer Foundayo.
Many of Lilly’s achievements in obesity have come in the form of growing the prescription base, with the U.S. launch of Foundayo in particular benefiting from a massive push to bring new patients into the fold. According to William Blair, regulatory reviews for the pill are ongoing in more than 40 markets.
Additionally, the temporary Medicare GLP-1 Bridge program that began granting improved access to obesity medications in July could also increase uptake in the U.S., growing coverage by an estimated 35% and providing access to around 20 million potential patients in the program, William Blair wrote.
On the regulatory side, Lilly is planning a regulatory submission for Foundayo’s use in type 2 diabetes this year, and for next-gen obesity drug retatrutide in obesity and overweight in the early months of 2027.
Earlier in its pipeline, Lilly could potentially read out mid-stage results for its antibody bimagrumab and oral small molecule GLP-1 naperiglipron—both of which target obesity—this year, William Blair noted.
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Novo’s R&D engine in Phase 3 gear
While Lilly leads in overall obesity revenue, Novo holds pole position in the oral market, claiming about 90% of weekly prescriptions with its Wegovy pill as of July That’s about 1.5 million people taking the drug, many of whom are new to the GLP-1s, the analysts added
And Novo is revving its own R&D engines in 2026, with several Phase 3 studies in the works. The company is scheduled to begin late-stage trials of its oral obesity medication zenagamtide and high-dose cagrilintide by the end of the year, according to William Blair. Novo is also expected to report results from a maintenance dose study of its combination treatment CagriSema. A regulatory decision for CagriSema—which comprises cagrilintide and semaglutide, the active ingredient in Wegovy—is expected in the fourth quarter. Novo also recently kicked off a Phase 3 study evaluating two different doses of oral Wegovy in an effort to find “the most optimal lower dose“ of the pill.
Novo has nonetheless had trouble keeping the fires burning, with a revenue stumble for the Wegovy pill in the second quarter, and analysts are watching closely to see whether the company can hold its initial oral lead.
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Roche embarks on key late-stage trials
While Roche’s lack of approved obesity drugs puts it behind the two standout leaders, the R&D-heavy Swiss pharma could gain clinical ground this year with several mid-stage readouts and a couple of late-stage trial starts on the docket.
The company is expected to report new data from a Phase 2 trial exploring enicepatide in patients with obesity and type 2 diabetes. The dual GLP-GIP agonist elicited 22.5% weight loss after nearly a year of treatment in a separate Phase 2 study of people with obesity, Roche revealed in January.
The second study has a completion date of Sept. 24 and William Blair expects the company’s Sept. 28 Pharma Day to shed light on its outcomes, as well as provide updates on other mid-stage trials for treatments like the once-daily oral CT-966, the antibody emugrobart in combination with Zepbound and the once-weekly injectable amylin drug petrelintide with partner Zealand Pharma
Roche’s later-stage trial starts planned for 2026 include studies of CT-996 and petrelintide, both in obesity.
While the company discarded drug candidate acmopatide earlier this year, Roche leaders have pointed to enicepatide in particular as a potential best-in-class asset.
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AstraZeneca expected to present amylin data this fall
AstraZeneca is moving forward with a Phase 3 trial in obesity and type 2 diabetes for its oral GLP-1 drug elecoglipron, which is also in a separate late-stage study for type 2 diabetes alone.
“We have a very competitive profile,” CEO Pascal Soriot said of elecoglipron during a media call in February to present the company’s full year 2025 earnings, adding that Roche would not move into Phase 3 “if we didn’t believe in the product.”
William Blair expects the trials to read out in 2027 or 2028.
As for remaining 2026 catalysts, the analysts expect data from AZD6234, a selective amylin receptor peptide agonist, to be presented at the European Association for the Study of Diabetes annual meeting, taking place Sept. 28 to Oct. 2 in Italy.
William Blair also expects results from a Phase 2 trial of AZD6234 in patients with overweight or obesity and type 2 diabetes who are currently on stable background GLP-1 therapy, and from the Phase 2b ASCEND study of GLP-1/glucagon dual agonist AZD9550 plus AZD6234 in obesity.
Pfizer prioritizes ‘ultra-long-acting’ GLP-1
After winning a high-profile bidding war to acquire obesity startup Metsera last year, Pfizer has trimmed one of the biotech’s oral assets from its pipeline. But William Blair analysts pointed to a Phase 3 trial of the drug candidate berobenatide, an ultra-long-acting GLP-1 receptor agonist that could stand out in the field thanks to its less-frequent administration.
Indeed, Pfizer is betting big on berobenatide this year in obesity, with plans to advance 10 Phase 3 studies this year, highlighting the value potential the company sees in the acquired asset.
Berobenatide’s value as a monthly therapy “hinges on Phase 3 results in 2028,” Leerink Partners said in a June note to investors.
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Also of note
With hundreds of billions of dollars on the line, AbbVie and Amgen are also throwing their hat in the weight loss ring, along with several smaller biotechs. William Blair pointed to key upcoming catalysts for programs from Viking Therapeutics, Structure Therapeutics, Zealand Pharma, Kailera Therapeutics and many more.
Viking’s lead obesity drug ‘stands out’
Viking’s lead asset VK2735, a novel GLP-1/GIP dual agonist, has “best-in-class potential” in both its oral and subcutaneous forms, William Blair said in a July note to investors. Data from a Phase 1 maintenance study of subcutaneous VK2735 are expected in the third quarter of this year, according to the analyst, with late-stage results due in the second half of 2027.
Structure’s aleniglipron ‘derisked’
Structure has begun a late-stage program for aleniglipron, as well as a series of earlier-stage trials for the oral small molecule GLP-1 that will read out this year In a note earlier this month, William Blair said aleniglipron has become derisked with data that is “sufficient . . . to effectively complete in the large and growing small-molecule GLP-1 receptor agonist class.”
AbbVie’s amylin analog off to ‘encouraging’ start
Off to a later start than many of its Big Pharma peers, AbbVie in March announced Phase 1 results for a long-acting amylin analog called ABBV-295 that William Blair analysts called “encouraging” and potentially competitive down the road. The asset elicited as much as 9.73% weight loss at 13 weeks in the multiple ascending dose portion of the trial.
Amgen’s all in on MariTide
Amgen’s dual-receptor agonist MariTide, which combines a GLP-1 with a GIP inhibitor, is in several Phase 3 trials that are set to read out over the next few years—nine ongoing and three planned “across obesity and related cardiometabolic conditions,” Amgen is working to position MariTide as the “best monthly” obesity drug
ObesityWeight lossGLP-1
PfizerEli Lilly and CompanyNovo NordiskAstraZenecaRocheAmgenAbbVie
