Evaluation of amnion-derived mesenchymal stem cells for treatment-resistant moderate Crohn's disease: study protocol for a phase I/II, dual-centre, open-label, uncontrolled, dose-response trial.

Introduction: The medical treatment options for patients with Crohn's disease (CD) are limited and patients resistant to those therapies are left requiring surgical operations that usually only achieve some symptomatic relief. Mesenchymal stem cells (MSC) have been shown to be effective for the treatment of CD, and we have demonstrated in animal experiments that human amnion-derived MSCs (AMSC) are a potential new therapeutic strategy. Therefore, we designed this study to investigate the safety and efficacy of AMSCs in patients with treatment-resistant CD.

Methods and analysis: This is the protocol for an ongoing phase I/II, dual-centre, open-label, uncontrolled, dose-response study. The estimated enrolment is 6-12 patients with treatment-resistant, moderate CD. A dose of 1.0×106 cells/kg will be administered intravenously in the low-dose group at days 0 and 7. After confirming the safety of low-dose administration, a dose of 4.0×106 cells/kg will be administered intravenously in the high-dose group on days 0 and 7. The primary endpoint will measure the occurrence of adverse events related to acute infusion toxicity, and secondary endpoints will include long-term adverse events and efficacy of AMSC administration.

Ethics and dissemination: The Institutional Review Board of Hokkaido University Hospital approved this study protocol (approval number H29-6). A report releasing study results will be submitted to an appropriate journal.

Discussion: This study is the first to investigate the safety and efficacy of AMSC use for CD treatment. Our results will advance studies on more efficient and convenient methods to overcome the limits of available CD treatments.

Trial registration number: UMIN000029841.