A Phase 2 Study of MORF-057, an Oral α4β7 Integrin Inhibitor in Moderately to Severely Active Ulcerative Colitis

Background & Aims: MORF-057 is an orally administered small-molecule drug that inhibits α4β7 integrin-mediated recruitment of α4β7-expressing lymphocytes to the gut, a process implicated in the pathology of ulcerative colitis (UC). This study evaluated the efficacy, pharmacokinetics, pharmacodynamics, safety, and tolerability of MORF-057 in participants with moderately to severely active UC. Methods: This open-label, phase 2a, single-arm, multicenter trial comprised a 6-week screening period, a 52-week active treatment period (including a 12-week induction period and 40-week maintenance period), and a 4-week safety follow-up period. Of the 35 participants enrolled in the main cohort, 18 participants received 100 mg of oral MORF-057 twice daily for the entire treatment period. The primary efficacy endpoint was a change in the Robarts Histopathology Index (RHI) score from baseline to week 12 and was assessed in all participants with evaluable data. Additional clinical, endoscopic, and histological variables were assessed at screening and at weeks 12 and 52. Results: MORF-057 was well tolerated, and no treatment-emergent serious adverse events were observed. At week 12, participants (n = 35) exhibited a mean change from baseline in RHI score of −6.4 (standard deviation, 11.2). Additionally, 22.9% of participants (8/35) achieved RHI remission (RHI score ≤3). In participants with evaluable data (n = 18), the effects of MORF-057 on pharmacokinetics, pharmacodynamics, and clinical efficacy were achieved at week 12 and remained consistent to week 52. Conclusions: Overall, this study demonstrated that oral MORF-057 is well tolerated, with promising efficacy for individuals with moderately to severely active UC. ClinicalTrials.gov,