Tenax Therapeutics Shares Plunge 85% After Phase 3 Heart Drug Misses Primary Endpoint

Tenax Therapeutics said on Monday, August 10, that its Phase 3 LEVEL study of TNX-103, an investigational treatment for chronic heart failure, failed to meet its primary endpoint, sending the company's shares down more than 85 percent in pre-market trading, RTTNews reported.

Setback for a Promising Mechanism

TNX-103 — a formulation of levosimendan, a calcium sensitizer that had shown promise in earlier trials — was being tested in the late-stage LEVEL study as a treatment for patients with heart failure with preserved ejection fraction. The miss leaves the drug's development program in question and removes a key value driver for the micro-cap biotech.

A Volatile Week for Drug News

The failure came in a busy stretch for US drug regulation. Earlier in the week, the FDA granted accelerated approval to Replimune's oncolytic immunotherapy Tudriqev (vusolimogene oderparepvec-wtpg) for advanced melanoma on August 6, closing out a regulatory saga that had twice ended in rejection, The Pharma Letter reported. Eli Lilly also announced on August 3 that the FDA had granted Breakthrough Therapy designation to olomorasib, a KRAS G12C inhibitor, for advanced pancreatic cancer.

Analysts said the Tenax result highlights the high attrition rate in late-stage cardiovascular trials, where several high-profile Phase 3 programs have failed in recent years despite promising Phase 2 data.