Theravance Biopharma has reported that its drug candidate izencitinib (TD-1473) failed to meet the primary endpoint in Phase IIb dose-finding induction clinical trial to treat ulcerative colitis.
Meant for oral administration, izencitinib is a pan-Janus kinase (JAK) inhibitor being jointly developed by Theravance and Janssen Biotech. The drug targets inflammation at the gastrointestinal disease site.
Theravance is specifically developing the drug for various inflammatory intestinal diseases such as ulcerative colitis and Crohn’s disease.
The randomised, double-blind, placebo-controlled, multi-centre Phase IIb trial enrolled adults with moderately-to-severely active ulcerative colitis.
Safety and efficacy results from this trial were expected to help determine induction and maintenance dose regimens for a confirmatory Phase III induction trial and a maintenance study that is underway.
However, top-line results showed that the Phase IIb trial did not meet its primary goal of change in the total Mayo score or the main secondary goal of clinical remission at week 8, when compared to placebo.
Data revealed a small dose-dependent rise in clinical response measured using the adapted Mayo score, due to a decrease in rectal bleeding.
All evaluated izencitinib doses were observed to be well-tolerated on oral administration once a day for eight weeks.
In addition, adverse event rates were comparable between the izencitinib and placebo arms.
Among patients treated with izencitinib, none reported perforation, major cardiovascular or thromboembolic event, opportunistic infection, complicated zoster or non-melanoma skin cancer.
The company added that the drug’s plasma exposure was low and in line with expectations for gut-selective therapy.
Theravance Biopharma CEO Rick Winningham said: “We plan to analyse the data to better understand the findings and the potential for optimisation of a gut-selective medicine as a treatment for patients with inflammatory bowel disease.”
Based on the anticipated ulcerative colitis data from the 16-week extended induction part of the trial and the 44-week maintenance study, the company plans to reduce future expenses related to izencitinib’s programme.
Theravance expects results from Phase II Crohn’s disease trial of izencitinib before the year-end or in the first quarter of next year.
In June 2021, the company reported top-line data from the Phase II trial, where nezulcitinib (TD-0903) failed to meet the primary endpoint in hospitalised Covid-19 patients with acute lung injury and impaired oxygenation.