GSK halts camlipixant development after mixed Phase 3 results curb blockbuster hopes

GSK announced it is stopping work on camlipixant, a P2X3 receptor antagonist it bought when acquiring Bellus Health in 2023, after the drug produced mixed results in two Phase 3 chronic cough trials.

In the Calm-1 study, a high dose of camlipixant lowered 24‑hour cough frequency at Week 12 compared with placebo, but it did not meet other prespecified endpoints. The Calm-2 trial showed no statistical benefit for the high dose at Week 24, and the low dose failed to achieve significance in either study, leaving both trials short of key secondary goals.

GSK described the overall efficacy as limited and unlikely to change patient care, prompting the company to end the program. Analysts had counted camlipixant on track to be a major 2026 catalyst, so the termination represents a notable setback for the drugmaker.