The following is a summary of “Efficacy and safety of gefapixant in women with chronic cough and cough-induced stress urinary incontinence: a phase 3b, randomised, multicentre, double-blind, placebo-controlled trial,” published in the November 2024 issue of Pulmonology by Birring et al. 

Researchers conducted a retrospective study to assess the effectiveness and safety of gefapixant in reducing cough-induced stress urinary incontinence (CSUI) episodes in women with refractory or unexplained chronic cough.  

They performed a phase 3b, double-blind, randomized, placebo-controlled trial across 90 sites in 12 countries with women aged 18 years or older, who had a chronic cough lasting at least 1 year, a diagnosis of refractory or unexplained chronic cough, a cough severity visual analogue scale score of 40 mm or more (with a maximum of 100 mm), and CSUI for 3 months or more. Participants were randomly assigned in a 1:1 ratio to receive either oral gefapixant or placebo for 12 weeks. The primary outcome measured was the percentage change from baseline in daily CSUI episodes, calculated as a 7-day average at week 12.  

The results showed that from May 10, 2020, to Sept 2, 2022, 375 participants were randomized to receive gefapixant 45 mg twice daily (n=185) or placebo (n=190). The mean age was 56.4 years (SD 11.4), with a mean chronic cough duration of 5.2 years (SD 6.6) and SUI duration of 4.0 years (SD 5.9). The least-squares mean percentage change from baseline in daily CSUI episodes was –52.8% (95% CI –58.4 to –47.1%) for gefapixant and –41.1% (95% CI –46.7 to –35.4%) for placebo (estimated treatment difference: –11.7% [95% CI –19.7 to –3.7]; P =0.004). Among the participants, 129 (70%) of 185 on gefapixant and 71 (37%) of 190 on placebo experienced at least 1 adverse event. Safety and tolerability aligned with previous gefapixant trials, with taste-related events being the most common.  

They concluded the gefapixant 45 mg twice daily was the first treatment to demonstrate efficacy over placebo in reducing CSUI episodes with refractory or unexplained chronic cough. 

Source: thelancet.com/journals/lanres/article/PIIS2213-2600(24)00222-4/abstract