Terns Pharma Halts Obesity Drug Development After Mid-Stage Trial Reveals Safety Concerns

Terns Pharmaceuticals has decided to discontinue the development of its experimental obesity drug, TERN-601, following disappointing results from a mid-stage trial. The once-daily oral medication, a GLP-1 receptor agonist, led to a modest 4.6% greater weight loss compared to a placebo over 12 weeks. However, the company concluded that this outcome did not meet the high standards required for a viable oral GLP-1 therapy.

Safety concerns also played a significant role in the decision. Approximately 11.9% of the 134 participants discontinued the drug due to side effects, primarily gastrointestinal issues like nausea and vomiting. More concerning were the three cases of serious liver enzyme elevations observed after treatment ended, with two cases linked to the drug, one of which was confirmed by a liver biopsy.

Terns noted that these liver toxicity signals were not anticipated, as earlier studies had not indicated similar problems. Analysts pointed out that TERN-601 shares a chemical structure with Pfizer’s discontinued drugs, danuglipron and lotiglipron, both of which were halted due to liver safety concerns.

As a result, Terns has decided to focus on its lead cancer drug, TERN-701, which targets chronic myeloid leukemia. The company does not plan to invest further in metabolic disease treatments.