Regeneron's olatorepatide Phase 2 obesity studies appear on the US registry

Two Phase 2 studies of olatorepatide, a GLP-1/GIP dual agonist that Regeneron licensed from Hansoh Pharma, have appeared on the US clinical trial registry, according to trial-monitoring records.^[1] One study plans to enroll 360 adults with overweight or obesity who do not have diabetes and is currently recruiting participants. A second, smaller US study with 120 participants is listed as active but no longer recruiting, meaning it has enough patients enrolled and is now following them through the trial.^[1]

The US studies follow Phase 3 results reported out of China in March 2026 by Hansoh Pharma, which holds rights to develop and sell the drug in mainland China, Hong Kong and Macau. Regeneron holds rights everywhere else.^[2] That Chinese trial enrolled 604 adults across 33 sites and tested once-weekly doses of 5 mg, 10 mg or 15 mg against placebo over 48 weeks. People taking the drug lost up to 19.3% of their body weight on average, and 97.2% of participants lost at least 5% of their starting weight.^[2] Weight loss was still trending downward at week 48, which researchers said suggests further loss might be possible with continued treatment.^[2]

The Chinese trial also reported a favorable side-effect profile compared with other drugs in its class. Nausea affected fewer than 10% of participants on average, and vomiting occurred in fewer than 5%. Rates of gastrointestinal side effects and people quitting the trial because of them were lower than those reported in earlier Phase 3 trials of similar dual-incretin drugs, according to the companies.^[2]

Regeneron is not developing olatorepatide alone. The company is pairing the incretin drug with two experimental antibodies, trevogrumab and garetosmab, which are designed to help preserve muscle mass during weight loss, part of its broader effort to improve the quality of weight loss rather than just the amount.^[2] Regeneron has said it plans to move olatorepatide into a registrational program later in 2026.^[2]

Why it matters for patients

Olatorepatide is not approved anywhere and has not been reviewed by the FDA or any other regulator, so it is not an option for patients today.^[2] The drug's safety and effectiveness have only been formally tested in a Chinese population so far; how it performs in a US population, where obesity trials often see somewhat different weight-loss results than in Asian populations, is not yet known.

For people already using approved GLP-1 drugs such as Ozempic, Wegovy, Mounjaro or Zepbound, olatorepatide represents another potential future option rather than an immediate one. The reported 19.3% weight loss and low rates of nausea and vomiting are notable, but Phase 3 results from one country do not guarantee the same outcome in US trials, and side effect rates can differ once a drug is tested in much larger and more diverse populations.^[2] The pairing with muscle-preservation antibodies is also unproven in humans at this stage.^[2]

What happens next

The 360-person US Phase 2 trial is still recruiting, and no completion date has been reported in the sources reviewed.^[1] The 120-person US study is active but not recruiting, meaning results are not expected soon.^[1] Regeneron has said it intends to start registrational, or approval-track, studies of olatorepatide later in 2026, but no specific US filing or approval timeline has been announced.^[2] Detailed data from the Chinese Phase 3 trial are expected to be presented at a future medical meeting and published in a peer-reviewed journal, which would allow independent experts to evaluate the results.^[2]