- Trial Phase
- Phase 3 (lead indication discontinued); Phase IIb ongoing in IBS-D/IBS-M
- Time to Market
- Unknown in the surviving IBS indication (Phase IIb — still years from any possible filing); effectively zero path to market in its lead indication, refractory chronic cough, where development was discontinued in July 2026.
- Why 1/10
- No hard dated catalyst remains: the pivotal Phase 3 program (CALM-1/CALM-2) resolved negatively in July 2026 — CALM-2 failed its primary endpoint and GSK discontinued camlipixant in refractory chronic cough — and the only surviving program is an early (Phase IIb) IBS trial with no dated readout at a ~$100B company where this drug no longer drives the thesis.
The defining binary has already passed and it was a miss: GSK booked a ~£1.9B impairment tied mostly to camlipixant that cut Q2 2026 operating profit by ~75% (to £481M), yet the stock is only a few percent off its 52-week high, confirming the drug is immaterial to a company this size. For GSK holders, watch the remaining Phase IIb IBS-D/IBS-M program for any signs of continued investment (or an eventual full exit from P2X3), and track competitors still chasing chronic cough (e.g., Trevi's Haduvio, Addex) as the class's commercial benchmark.
Price Chart
Executive Summary
Camlipixant (development code BLU-5937) was GSK's $2B-plus bet in the P2X3 antagonist race for refractory chronic cough, a drug acquired with Bellus Health. The binary outcome already landed badly: the confirmatory Phase 3 CALM-2 trial missed its primary endpoint at week 24 even though the first study (CALM-1) hit at week 12, and GSK has discontinued the program in chronic cough. The failure forced a roughly £1.9B impairment that cut GSK's Q2 2026 operating profit about 75%, though GSK reaffirmed full-year guidance and the stock remains near its highs — a measure of how small one failed drug is inside a ~$100B company. A Phase IIb IBS program is the only thing left for the molecule.
How It Works
Camlipixant is a small-molecule pill that blocks P2X3 receptors on sensory nerve endings in the airways and gut — receptors that fire 'cough now' and pain signals. Blocking them was meant to quiet the hypersensitive cough reflex in people with chronic cough that persists despite treatment, while avoiding the severe taste disturbances that plagued earlier drugs in the same class (e.g., Merck's gefapixant).
Trial Status
Per GSK's July 2026 announcement (SEC 6-K): Phase 3 CALM-1 in refractory chronic cough met its primary endpoint (50mg twice-daily at week 12), but the confirmatory CALM-2 trial failed to reach statistical significance on the same endpoint at week 24; the 25mg dose missed in both studies and key secondary endpoints did not meet thresholds. GSK discontinued camlipixant in refractory chronic cough. The Phase 3 RCC study NCT05599191 (BLU-5937, 957 patients, sponsor 'Bellus Health Inc. - a GSK company') completed June 2026 with results not yet posted; a Phase IIb trial in IBS-D/IBS-M continues.
The Two-Sided Case
Upcoming Catalysts
- Phase IIb IBS-D/IBS-M data for camlipixant (no public date; not a scheduled binary in the next 12 months)
- Posting of results for completed Phase 3 study NCT05599191 on ClinicalTrials.gov (already complete June 2026, results not yet posted)
- GSK's 'Accelerate Growth' restructuring — pipeline prioritization decisions could formally shelve or out-license the remaining camlipixant program
- Competitor chronic-cough readouts (e.g., Trevi's Haduvio in IPF-related cough) as the class's commercial yardstick
Source Filing
The SecBot filing or press-release report that triggered this drug report:
GSK plc 6-K GSK ·Originating report