Terns Pharmaceuticals is discontinuing its oral GLP-1 obesity candidate, TERN-601, after Phase 2 data showed modest weight loss and unexpected liver enzyme elevations. The 12-week trial reported up to 4.6% placebo-adjusted weight loss, with 12% of participants discontinuing due to gastrointestinal side effects. Two of three liver enzyme cases were deemed drug-related. The company will now focus on its oncology program, advancing TERN-701 for chronic myeloid leukemia.
Drug Trial Phases
Phase 1 trials assess safety in small groups of 20–100 participants, with about 70% of drugs advancing to the next stage.
Phase 2 evaluates efficacy and dosing in 100–300 patients, but only around 30% move forward, making Phase 2 a critical go/no-go decision point.
Phase 3 confirms safety and effectiveness in 1,000–3,000+ patients, and about 25–30% reach the approval stage.
TERN-601’s early success in Phase 1 did not carry through to later testing, a reminder of how few investigational drugs ultimately reach patients.
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