MIRICURE: Mirikizumab With Curettage and Repair (Closure) for Perianal Fistulizing Crohn's Disease

MIRICURE: Mirikizumab With Curettage and Repair (Closure) for Perianal Fistulizing Crohn's Disease

This Phase 4, single-arm, open-label study will evaluate the effectiveness and safety of mirikizumab combined with surgical curettage and closure in adults with active perianal fistulizing Crohn's disease. Fifty participants with complex draining fistulas will undergo staged surgical management followed by mirikizumab induction and maintenance therapy. The primary endpoint is combined clinical remission and radiologic response at Week 24. Participants will be followed through Week 48.

Perianal fistulizing Crohn disease is a severe manifestation of Crohn disease associated with persistent fistula drainage, impaired quality of life, and substantial morbidity. Although biologic therapies have improved outcomes, durable fistula healing remains uncommon, and optimal treatment strategies continue to be defined.

Mirikizumab is an interleukin-23 p19 antagonist approved for the treatment of moderately to severely active Crohn disease. Surgical management, including fistula tract curettage and closure of the internal opening, has demonstrated favorable outcomes when incorporated into multidisciplinary treatment approaches for complex perianal fistulas.

This Phase 4, multicenter, single-arm, open-label study will enroll approximately 50 adults with active complex perianal fistulizing Crohn disease. Participants will undergo examination under anesthesia with fistula tract curettage and seton placement prior to initiation of mirikizumab induction therapy. After 8 to 10 weeks of treatment, participants will undergo repeat examination under anesthesia with seton removal, repeat curettage, and closure of the internal fistula opening. Participants will receive mirikizumab induction followed by maintenance therapy and will be followed for 48 weeks.

Pelvic MRI will be performed at Weeks 12, 24, and 48 and evaluated using standardized MAGNIFI-CD and TOpCLASS criteria. Clinical assessments, patient-reported outcome measures, safety evaluations, and quality-of-life assessments will be collected throughout the study.

The primary objective is to evaluate the proportion of participants achieving combined clinical remission and radiologic response at Week 24. Secondary objectives include evaluation of clinical remission, radiologic remission, fistula healing, quality of life, disease activity, and safety through Week 48.

Inclusion Criteria:

• Adults ≥18 years
• Diagnosis of Crohn disease for at least 3 months
• Active draining complex perianal fistula
• Able to provide informed consent

Exclusion Criteria:

• Rectovaginal fistula
• Only low intersphincteric or submucosal fistulas
• Severe proctitis preventing surgical closure
• Stoma
• Active tuberculosis
• Active hepatitis B
• Active serious infection
• Pregnancy
• Concurrent investigational drug trial
• MRI contraindication
• Additional laboratory exclusions as specified in the protocol