Kailera's Oral GLP-1 Pill HRS-7535 Succeeds in Phase 3 China Trial but Sparks Severe Tolerability Concerns
Newly public biotech challenger Kailera Therapeutics (NASDAQ: KLRA) and its China-based partner, Hengrui Pharma, announced positive topline results on July 7, 2026, from two Phase 3 clinical trials of their once-daily oral small-molecule GLP-1 receptor agonist, HRS-7535 (also known as KAI-7535). While the drug demonstrated competitive weight-loss efficacy and a clean liver safety profile, it was marred by exceptionally high rates of gastrointestinal (GI) side effects that have alarmed market analysts.
Clinical Efficacy and Safety Profile
In a 44-week Phase 3 trial conducted in China for chronic weight management, HRS-7535 achieved a mean weight loss of 9.8% at the highest daily dose tested. In a separate Phase 3 trial, the drug also demonstrated significant reductions in HbA1c (blood sugar) among patients with Type 2 diabetes.
Crucially, the trials revealed no signs of liver toxicity or drug-induced liver injury (DILI). This is a major regulatory relief for Kailera, as liver safety has been a persistent concern for oral small-molecule GLP-1 receptor agonists due to structural similarities to Pfizer's discontinued candidate, danuglipron.
Exceptional GI Tolerability Challenges
Despite the positive efficacy and liver safety, the trial surfaced severe gastrointestinal side effects that could limit its commercial competitiveness:
- 70% of patients receiving the highest dose experienced nausea.
- 67% to 69% of patients reported vomiting.
William Blair analyst Andy Hsieh noted that these numbers "alarmed" his team, stating that Kailera must reduce these rates to the mid-30% and mid-20% levels, respectively, to maintain a competitive profile against Eli Lilly's Eli Lilly's Market Dominance: Surging U.S. Adoption, Blowout Tirzepatide Sales, and Foundayo Oral Launch Success (orforglipron) and Novo Nordisk's oral Wegovy tablet.
Strategy to Mitigate GI Side Effects
To address these tolerability issues, Kailera is currently conducting a global Phase 2 trial of HRS-7535. This trial is designed to test a lower starting dose and is exploring a "nighttime" dosing cohort to see if administering the pill before sleep can help patients tolerate the medication better.