XEN-D0501, a novel transient receptor potential vanilloid 1 antagonist, does not reduce cough in patients with refractory cough

This was a double-blind, randomized, placebo-controlled crossover study designed to evaluate the anti-tussive efficacy of XEN-D0501 versus placebo in 28 patients with refractory chronic cough. The primary endpoint was awake cough frequency, along with sleep and 24-hour cough frequency. Secondary endpoints included changes from baseline in cough severity and frequency and cough-specific QoL, while capsaicin-evoked cough response was included as a pharmacodynamic endpoint. Ambulatory cough monitoring comprised 24-hour acoustic recordings made using the Vitalograph VitaloJAK device.