Trevi Therapeutics concluded enrolment early in the Phase II CANAL trial of Haduvio (nalbuphine ER) to treat chronic cough in patients with idiopathic pulmonary fibrosis (IPF). The decision to conclude comes after the company previously revealed statistically significant efficacy interim assessment data from the trial.

The interim analysis was carried out on 26 trial subjects, validating the proof of concept. Nearly 40 participants were enrolled in the trial.

On the primary efficacy endpoint, treatment with Haduvio offered a 77.3% decline in the frequency of daytime cough from baseline versus a 25.7% decline in the placebo arm.

This interim data indicated a 52% placebo-adjusted decline in the geometric mean percent change in the frequency of daytime cough.

The trial centres were alerted to enrol eligible subjects who were being screened without needing further recruitment.

Trevi anticipates efficacy and safety data from the full set of participants in the third quarter of this year.

Haduvio is an oral extended-release formulation of nalbuphine, which is a combined ĸ-opioid receptor agonist and µ-opioid receptor antagonist.

Injectable nalbuphine is approved for use in the US and Europe and is marketed for pain indications for over two decades.

The randomised, double-blind, placebo-controlled, two-treatment, two-period crossover trial in the UK is analysing the safety and efficacy of nalbuphine ER for chronic cough in IPF patients. 

It has two treatment periods of three weeks, with a washout period of two weeks following each treatment period. 

Analysing the impact of nalbuphine ER tablets on the mean daytime cough frequency at day 22 versus placebo as assessed by an objective cough monitor is the trial’s primary efficacy endpoint.

In February this year, the company concluded subject enrolment in the Phase IIb/III PRISM trial of Haduvio for pruritus associated with prurigo nodularis.