Hengrui Pharma has released late-stage trial data for its injectable dual GLP-1/GIP receptor agonist, HRS9531, showing the drug led to significant weight reduction in adults with overweight or obesity. The phase 3 study was conducted in China and included 531 adults without diabetes who were administered 2 mg, 4 mg, or 6 mg weekly subcutaneous doses, or placebo.
The topline results indicate that HRS9531 achieved a mean weight reduction of up to 17.7%, or 16.3% after adjusting for placebo. A prespecified supplemental analysis showed that participants receiving the 6 mg dose achieved an average weight loss of 19.2%. The trial met its primary endpoint, with all three dosing groups showing statistically significant weight reduction compared to placebo at 48 weeks.
According to Hengrui, approximately 88% of participants who received HRS9531 achieved at least 5% weight loss, while 44.4% reached a reduction of at least 20%. Most adverse events were gastrointestinal in nature and ranged from mild to moderate in severity.
The phase 3 data follows earlier phase 2 results, where an 8 mg dose of the drug achieved a mean weight loss of 22.8% at 36 weeks. That dose level was not included in the phase 3 study. The drug is being co-developed with Kailera Therapeutics, a U.S.-based company that intends to examine the effects of higher doses and longer treatment durations in global clinical programs.
“We commend our colleagues at Hengrui for these impressive phase 3 clinical results, building on the strong momentum behind HRS9531 (KAI-9531),” said Kailera CEO Ron Renaud. He stated that Kailera is preparing to launch a global clinical development program to further explore the candidate.
The dual agonist is also known as KAI-9531 outside China, where Kailera holds development and commercialization rights. Kailera was launched in October 2024 with $400 million in funding and an initial pipeline that includes HRS9531 and three other obesity-focused therapies. These include KAI-4729, a triple-agonist targeting GLP-1, GIP, and glucagon receptors; KAI-7535, an oral GLP-1 receptor agonist; and an oral formulation of KAI-9531.
Hengrui plans to submit a new drug application in China for HRS9531 for chronic weight management. The full dataset from the phase 3 trial will be presented at an upcoming scientific meeting.
Hong Chen, Head of Metabolism Department I at Hengrui, stated, “The positive data from the HRS9531-301 study demonstrated meaningful, sustained weight loss.” Chen also noted that the company is working to accelerate the development of the drug based on the phase 3 outcomes.
