Theravance tanks as Phase IIb trial of izencitinib fails in ulcerative colitis

Ireland-incorporated drug developer Theravance Biopharma (Nasdaq: TBPH) saw its shares plummet 27.5% to $10.33 pre-market today, after it announced top-line results from its Phase IIb dose-finding induction study of izencitinib, an orally administered, gut-selective pan-Janus kinase (JAK) inhibitor in development for the treatment of ulcerative colitis.

The study did not meet its primary endpoint of change in the total Mayo score or the key secondary endpoint of clinical remission at week 8, relative to placebo. There was a small dose-dependent increase in clinical response measured by the adapted Mayo score, which was driven by a reduction in rectal bleeding.

At all doses, izencitinib was well-tolerated when administered orally once daily for 8 weeks; adverse event rates were similar among patients receiving izencitinib and placebo. There were no instances of perforation, opportunistic infection, major cardiovascular or thromboembolic event, complicated zoster, or non-melanoma skin cancer in patients receiving izencitinib. There were no notable changes in lab values including creatine phosphokinase and lipids in patients receiving izencitinib relative to placebo. Plasma exposure of izencitinib was low, consistent with expectations for a gut-selective medicine.