Lilly Posts Phase 3 Results for Oral Orforglipron in Japan-Only ATTAIN-J Obesity Trial

Eli Lilly and Company posted results on ClinicalTrials.gov on July 20, 2026 for ATTAIN-J, a phase 3 trial of its oral GLP-1 receptor agonist orforglipron in adults with obesity in Japan. The trial, registered as NCT05931380, is titled "A Phase 3, Randomized, Double-Blind Study to Investigate the Efficacy and Safety of Once-Daily Oral LY3502970 Compared With Placebo in Japanese Adult Participants With Obesity Disease." As of this report, Lilly had not issued a separate press release describing the findings; the ClinicalTrials.gov results posting is the only public disclosure of the trial's outcome data.

The study enrolled 238 adults at sites in Japan between July 2023 and its primary completion in June 2025. Eligible participants had a body mass index of at least 27 kg/m2 with two or more obesity-related health problems, or a BMI of at least 35 kg/m2 with at least one such problem, and a self-reported history of at least one unsuccessful weight-loss attempt. Participants were randomly assigned in roughly equal groups to once-daily oral placebo (60 participants) or orforglipron at a target dose of 6 mg (61 participants), 12 mg (57 participants) or 36 mg (60 participants), with dose escalation from 1 mg over the initial weeks of treatment. At baseline, participants averaged 53 to 56 years of age and 87 to 89 kilograms in body weight across the four groups.

The trial's two primary endpoints were percent change in body weight and the proportion of participants achieving at least 5 percent weight loss, both measured from baseline to week 72. Least-squares mean body weight change was minus 0.6 percent with placebo, compared with minus 5.9 percent at the 6 mg dose, minus 8.7 percent at 12 mg, and minus 7.9 percent at 36 mg. The proportion of participants losing at least 5 percent of body weight was 15.0 percent with placebo versus 45.9 percent, 61.4 percent and 58.3 percent at the 6 mg, 12 mg and 36 mg doses, respectively. On both endpoints, the 12 mg dose numerically outperformed the 36 mg dose in this trial.

Secondary endpoints followed a similar pattern. At least 10 percent weight loss was reported in 3.3 percent of the placebo group versus 18.0 percent, 35.1 percent and 38.3 percent at the 6 mg, 12 mg and 36 mg doses. At least 15 percent weight loss occurred in none of the placebo group versus 9.8 percent, 22.8 percent and 18.3 percent at the three ascending doses, and at least 20 percent weight loss occurred in 3.3 percent and 12.3 percent of the 6 mg and 12 mg groups and 8.3 percent of the 36 mg group, with no placebo participants reaching that threshold.

Of the 238 participants who received at least one dose, 214 completed the study, with 54 of 60, 54 of 61, 52 of 57 and 54 of 60 completing in the placebo, 6 mg, 12 mg and 36 mg groups respectively. Serious adverse events were reported in 5 of 60 participants on placebo, 1 of 61 on 6 mg, 3 of 57 on 12 mg, and 6 of 60 on 36 mg, with individual events including myocardial ischemia, sudden hearing loss, chest pain, appendicitis and breast cancer, each occurring in one or two participants scattered across the treatment groups. One death was recorded among the 60 participants assigned to the 36 mg dose; the ClinicalTrials.gov results posting reports the death count within the adverse-events tables but does not specify a cause or an investigator assessment of relatedness to the study drug. Non-serious gastrointestinal adverse events rose with dose: constipation was reported in 5 of 60 placebo participants versus 22 of 61, 16 of 57 and 19 of 60 at ascending orforglipron doses, nausea in 0 of 60 placebo participants versus 8, 9 and 20 at the three doses, and diarrhea and vomiting followed a similar dose-related pattern.

Orforglipron is a non-peptide, small-molecule GLP-1 receptor agonist taken as a once-daily tablet. The U.S. Food and Drug Administration approved it under the brand name Foundayo on April 1, 2026 for chronic weight management in adults with obesity, or overweight with weight-related conditions, based on the global ATTAIN Phase 3 program, which Lilly has said enrolled more than 4,500 people across two registration trials, ATTAIN-1 and ATTAIN-2. Orforglipron is not authorized in Japan, the European Union or Australia. ATTAIN-J is a Japan-specific trial within the broader ATTAIN program; its results posting does not itself constitute a regulatory filing or approval in Japan or any other market, and this report describes trial-level data rather than dosing or treatment guidance.