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# Neumora Halts Development of Navacaprant After Phase 3 Miss
- URL: https://www.fdaweb.com/neumora-halts-development-of-navacaprant-after-phase-3-miss/
- Published: 2026-06-15T12:00:00.000Z
- Updated: 2026-09-14T13:41:08.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5161313

Neumora Therapeutics says it is discontinuing development of its lead depression candidate navacaprant after two Phase 3 studies failed to meet their primary and key secondary endpoints in patients with major depressive disorder (MDD).

The company is reporting that both the KOASTAL-2 and KOASTAL-3 trials failed to demonstrate a statistically significant improvement over placebo on the Montgomery-Asberg Depression Rating Scale (MADRS), dealing a major setback to Neumora's efforts to develop what had been one of the most advanced kappa opioid receptor antagonists in late-stage clinical testing.

The two Phase 3 studies enrolled a combined 852 patients. In KOASTAL-2, patients receiving navacaprant 80 mg experienced a mean reduction of 12.2 points on the MADRS score from baseline at six weeks, compared with a 12.0-point reduction for placebo-treated patients, a difference that was not statistically significant, the company says. In KOASTAL-3, navacaprant-treated patients demonstrated a 10.1-point reduction in MADRS scores compared with a 10.8-point reduction among placebo recipients, also failing to achieve statistical significance.

Neumora also reported results from a pre-specified analysis of patients enrolled after protocol optimizations implemented in early 2025\. That analysis likewise showed no meaningful difference between navacaprant and placebo, with both groups demonstrating a 12.1-point improvement on the MADRS scale.

Despite the efficacy failure, the company said navacaprant was generally well tolerated and exhibited a safety profile consistent with previous studies.

"While we are disappointed with the results of the KOASTAL-2 and -3 studies, we want to extend our gratitude to the patients, families, dedicated investigators, Neumora team and others who contributed meaningfully to the KOASTAL program," said Bill Aurora, chief operating and development officer.

The decision to terminate navacaprant shifts Neumora's focus to three remaining clinical programs targeting neurological and metabolic disorders.