Dextromethorphan-bupropion (AXS-05) - (SUMMIT)

Aug. 31, 2026: Axsome Therapeutics (NASDAQ: AXSM) announced first-patient-dosed in the SUMMIT Phase 3 trial of AXS-05 (dextromethorphan-bupropion) for smoking cessation. SUMMIT is a randomized, double-blind, active- and placebo-controlled, multicenter study in adult smokers, with patients assigned 1:1:1 to AXS-05, bupropion, or placebo for about 12 weeks. The primary endpoint is smoking abstinence at the end of the 12-week treatment period.

AXS-05 is described as an oral investigational NMDA receptor antagonist, sigma-1 agonist, and aminoketone CYP2D6 inhibitor. The release notes that AXS-05 is already approved in the U.S. as AUVELITY for major depressive disorder in adults and for agitation associated with dementia due to Alzheimer’s disease, but it is not FDA-approved for smoking cessation.

The announcement is a clinical-trial initiation milestone; no efficacy or safety results were reported, and no readout or regulatory decision date was provided.