Improvements in Objective and Subjective Measures of Chronic Cough with Gefapixant: A Pooled Phase 3 Efficacy Analysis of Predefined Subgroups

Introduction: In phase 3 trials (COUGH-1/COUGH-2), gefapixant 45 mg twice daily significantly reduced 24-h cough frequency vs placebo in refractory or unexplained chronic cough (RCC or UCC). Methods: Here, the efficacy of gefapixant 45 mg vs placebo was evaluated across COUGH-1/COUGH-2 in predefined subgroups based on sex, region, age, cough duration, cough severity, cough frequency, and diagnosis (RCC, UCC). Awake cough frequency reductions at Week 12 and LCQ response rates (i.e., ≥ 1.3-point improvement) at Week 24 were assessed. Results: Among 1360 participants analyzed, gefapixant 45 mg resulted in consistent awake cough frequency reductions overall and across predefined subgroups at Week 12. Gefapixant also resulted in improved LCQ scores across subgroups at Week 24; ≥ 70% of participants in each subgroup treated with gefapixant 45 mg had an LCQ response. Conclusion: These data suggest gefapixant 45 mg provides consistent objective and subjective efficacy across subgroups of individuals with RCC or UCC.