A single-center, phase 1/2a trial of hESC-derived mesenchymal stem cells (MR-MC-01) for safety and efficacy in interstitial cystitis patients.

This study investigated the safety and efficacy of MR-MC-01, a mesenchymal stem cell therapy derived from human embryonic stem cells, in patients with interstitial cystitis (IC), particularly those with Hunner lesions unresponsive to pentosan polysulfate sodium (PPS). Conducted as a prospective, randomized, double-blind, placebo-controlled phase I/IIa clinical trial, it enrolled 22 patients, with six completing phase I and 16 participating in phase IIa. Phase I tested 2 doses (2.0 × 107 and 5.0 × 107 cells) to determine the maximum tolerated dose (MTD), revealing no dose-limiting toxicities and only mild adverse events such as transient hemorrhage and bladder pain. In phase IIa, 12 participants received the MTD of 5.0 × 107 cells, and 4 received placebo. Significant reductions in interstitial cystitis questionnaire (ICQ) and pain urgency frequency (PUF) scores were observed in the treatment group. Improvements were noted in nocturnal voiding frequency and Hunner lesion size, with 8 patients showing either a reduction or complete resolution of lesions after 6 months. The global response assessment (GRA) reported moderate to marked improvement in 41.67% of treated patients versus 25% in the placebo group. MR-MC-01 demonstrated no serious drug-related adverse events, highlighting its favorable safety profile. These findings suggest that MR-MC-01 not only alleviates symptoms but also promotes structural recovery in IC, making it a promising treatment option. Further large-scale, long-term studies are warranted to confirm these results and optimize therapeutic protocols. (Identifier: NCT04610359).