RecruitingPhase 2Biological interventionDB-3Q bmMSC-EVs in Patients With Perianal Fistulizing Crohn's DiseaseThis is a double-blind, randomized, placebo-controlled, sequential cohort, ascending dose clinical trial to evaluate the safety and determine the efficacy of ascending doses of DB-3Q for the treatment of Perianal Fistulizing Crohn's Disease.