Regeneron’s Chinese partner reported Zepbound-like efficacy in a phase 3 trial, de-risking one part of the Big Biotech’s differentiated play for the obesity market.
New York-based Regeneron made a late entry to the obesity space last summer when it paid Hansoh Pharma $80 million upfront for a phase 3 candidate. Like Eli Lilly’s market-leading Zepbound, Hansoh’s olatorepatide drives weight loss by hitting the GLP-1 and GIP receptors. At the time, Regeneron said phase 2 data suggested olatorepatide may have a similar profile to Zepbound.
Hansoh provided more evidence of the similarity to Zepbound over the weekend, publishing data from a phase 3 trial that randomized 604 adults in China to receive one of three olatorepatide doses or placebo. At Week 48, Hansoh reported mean weight loss of up to 19.3% in the olatorepatide cohorts.
The result supports the claim the drug candidate has Zepbound-like efficacy. In a trial in a similar patient population, Lilly reported weight loss of up to 20.9% at Week 72. Participants in Lilly’s trial continued to lose weight between weeks 48 and 72. If Hansoh’s trial follows a similar trajectory, olatorepatide could deliver near-identical weight loss to Zepbound.
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With Zepbound well established, companies will likely need to do more than match the incumbent to win significant market share. This may go some way toward explaining why Regeneron’s shares were down more than 2.3% premarket Monday morning on the news.
But tolerability is one potential point of differentiation Hansoh can point to outside of efficacy. The company saw lower rates of gastrointestinal adverse events and treatment discontinuations than in phase 3 trials of other GLP-1/GIP receptor agonists.
Average nausea and vomiting rates were below 10% and 5%, respectively. Nausea affected 25% to 29% of participants across the three Zepbound doses in Lilly’s phase 3 program. Rates of vomiting on Lilly’s drug ranged from 8% to 13%.
Regeneron plans to start a global phase 3 registrational program this year. The company’s road map for 2026 includes the start of pivotal monotherapy studies and clinical development of a coformulation of olatorepatide with Praluent. GLP-1 drugs have little effect on LDL cholesterol, leading Regeneron to spot a chance to combine olatorepatide with its PCSK9 antibody for people with obesity and hyperlipidemia.
With hundreds of thousands of people taking a GLP-1 and a PCSK9 inhibitor, Regeneron sees a market for a product that combines the mechanisms. BMO Capital Markets analysts said in a note to investors in January that they “remain cautious on the market opportunity given potentially different need for LDL-C lowering regimen vs. incretins during weight maintenance setting.”