Kailera Therapeutics has unveiled promising phase 2 trial results for its obesity treatment, HRS9531, following a successful $400 million series A funding round. The company, in collaboration with Jiangsu Hengrui Pharmaceuticals, revealed that patients who received the injectable GLP-1/GIP receptor dual agonist lost an average of 22.8% of their body weight over 36 weeks.
The trial, conducted by Hengrui Pharma in China, involved 61 participants who were overweight or obese but did not have Type 2 diabetes. Forty-nine of the participants were given weekly injections of HRS9531, starting with a dose that increased to 8 mg over 24 weeks, followed by a consistent 8 mg dose for another 12 weeks. The remaining 12 patients received a placebo.
At the end of the 36-week period, the HRS9531 group experienced an average weight loss of 22.8%. After adjusting for the placebo group, the weight loss was 21.1%. Nearly 60% of participants lost at least 20% of their body weight, with some continuing to lose weight by Week 36, suggesting that HRS9531 may surpass the 22.8% weight loss observed.
The results position HRS9531 as a strong competitor to Eli Lilly’s Zepbound, which also targets GLP-1 and GIP receptors. Zepbound was approved after showing a 20.9% weight loss over 36 weeks, with further weight loss observed by Week 88. Kailera views these results as a benchmark for evaluating HRS9531 in future studies.
Previously, Kailera and Hengrui Pharma demonstrated the potential of HRS9531 in an earlier phase 2 trial, where doses up to 6 mg resulted in a maximum 16.7% placebo-adjusted weight loss.
The companies have not yet released safety and tolerability data for the 8-mg dose. However, they reported that adverse events were generally mild and in line with the known profile of GLP-1/GIP receptor dual agonists, with gastrointestinal issues mainly occurring during dose titration. At the 6-mg dose, nausea, diarrhea, and vomiting were reported by 33%, 31%, and 29% of participants, respectively.
Hengrui Pharma is already progressing phase 3 trials for both obesity and Type 2 diabetes in China. Kailera CEO Ron Renaud stated that the company is focused on expanding its clinical and manufacturing teams to move HRS9531, now named KAI-9531, into global phase 3 trials.
