Oral ribupatide from Hengrui and Kailera shows 12.1% weight loss at 26 weeks in Phase 2 trial

On February 10, 2026, Hengrui Pharma and Kailera Therapeutics reported that once-daily oral ribupatide produced mean weight loss of up to 12.1% at 26 weeks in a Phase 2 trial of 166 adults with obesity in China, with no plateau in weight loss observed at that point ^[1].

The study, called HRS9531-T-201 (NCT06841445), was a randomized, double-blind, placebo-controlled trial run by Hengrui in China. It enrolled adults 18 and older with a BMI of at least 28 and without type 2 diabetes, and assigned them in equal groups to 10 mg, 25 mg or 50 mg of oral ribupatide once daily, or to placebo ^[1]. Doses were stepped up on a simple schedule: participants reached 10 mg and 25 mg by Week 4 and 50 mg by Week 8 ^[1].

At Week 26, using the efficacy estimand, which assumes participants stayed on their assigned treatment, average weight loss was 6.9% at 10 mg, 12.1% at 25 mg and 12.1% at 50 mg, compared with 2.3% on placebo ^[1]. Using the treatment policy estimand, which includes the impact of people who stopped treatment early or used other weight-loss therapies, the figures were 6.7% at 10 mg, 11.9% at 25 mg and 11.4% at 50 mg, compared with 2.1% on placebo ^[1].

The companies also reported how many participants crossed specific thresholds. At 25 mg, 59.1% of participants lost at least 10% of their body weight and 38.6% lost at least 15%. At 50 mg, 52.5% lost at least 10% and 37.5% lost at least 15% ^[1].

Most treatment-emergent adverse events were mild to moderate and gastrointestinal, according to the companies. Vomiting was reported in 2.4% of participants at 10 mg, 11.4% at 25 mg and 7.5% at 50 mg. Nausea was reported in 11.9%, 22.7% and 20.0%, respectively ^[1]. No permanent treatment discontinuations or dose reductions because of nausea, vomiting, diarrhea or constipation were reported among participants taking oral ribupatide ^[1].

Ribupatide is also being developed as a once-weekly injection. In earlier results from a Hengrui trial in China, the 8 mg injectable dose produced mean weight loss of 23.6% at Week 36, compared with 1.8% on placebo, with no plateau ^[1]. The injectable form is now in the global Phase 3 KaiNETIC program ^[1].

Why it matters for patients

All of the results reported so far come from a single mid-stage trial of 166 people in China who did not have type 2 diabetes ^[1]. How the drug performs in larger trials, in people with diabetes, or in US patients has not been reported. Phase 2 trials are smaller and shorter than the studies regulators usually require, and the 26-week results do not show how much weight loss continues after that point, though the companies said they saw no plateau ^[1].

The trial compared oral ribupatide only with placebo, so there is no head-to-head information showing how it compares with approved GLP-1 obesity medicines ^[1]. Full trial data are expected at a scientific conference, but the companies have not disclosed which one or when ^[1].

The side-effect rates were not uniform across doses: nausea was higher at 25 mg than at 50 mg, and vomiting was also higher at 25 mg ^[1]. The companies did not explain that pattern. The oral tablet is not available by prescription, and no regulatory submission for the oral form has been reported ^[1].

What happens next

Hengrui says it will rapidly advance once-daily oral ribupatide into Phase 3 trials in China, and Kailera plans to start a global Phase 2 trial in 2026 ^[1]. The two companies have not given start dates for either study.

The injectable version of ribupatide is being tested in the KaiNETIC global Phase 3 program ^[1]. Hengrui has submitted a marketing authorization application to China's National Medical Products Administration for ribupatide for long-term weight management in adults; the companies have not said when that decision is expected ^[1]. Kailera holds exclusive rights to develop and sell ribupatide outside Greater China under a May 2024 agreement ^[1].