Randomised placebo-controlled multicentre trial to evaluate the efficacy and safety of JTR-161, allogeneic human dental pulp stem cells, in patients with Acute Ischaemic stRoke (J-REPAIR)

Introduction JTR-161 is a novel allogeneic human cell product consisting of dental pulp stem cells isolated from the extracted teeth of healthy adults. It is currently under development as a cell-based therapy for ischaemic stroke. The aim of this study is to evaluate the safety and efficacy of JTR-161 in patients with acute ischaemic stroke when given as a single intravenous administration within 48 hours of symptom onset.Methods and analysis This is a first-in-human, randomised, double-blind, placebo-controlled, multicentre, phase 1/2 clinical trial to be conducted in Japan (from January 2019 to July 2021). Patients with a clinical diagnosis of anterior circulation ischaemic stroke with a National Institutes of Health Stroke Scale (NIHSS）score of 5–20 at baseline were enrolled. Patients previously treated with recombinant tissue-type plasminogen activator and/or endovascular thrombectomy were allowed to be enrolled. The study consists of three cohorts: cohorts 1 and 2 (each eight patients) and cohort 3 (60 patients). Subjects were randomly assigned to receive either JTR-161 or placebo in a 3:1 ratio in cohorts 1 and 2, and in a 1:1 ratio in cohort 3. The number of cells administered was increased sequentially from 1×108 (cohort 1) to 3 x 108 (cohort 2). In cohort 3, the higher tolerated dose among the two cohorts was administered. The primary endpoint is the proportion of patients who achieve an excellent outcome as defined by all of the following criteria at day 91 in cohort 3: modified Rankin Scale ≤1, NIHSS ≤1 and Barthel Index ≥95.Ethics and dissemination The protocol and informed consent form were approved by the institutional review board at each participating study site. A manuscript with the results of the primary study will be published in a peer-reviewed journal.Trial registration number NCT04608838; JapicCTI-194570 and Clinical Trials. gov.