Septic shock is associated with substantial burden in terms of both mortality and morbidity for survivors of this illness. Pre-clinical sepsis studies suggest that mesenchymal stem (stromal) cells (MSCs) modulate inflammation, enhance pathogen clearance and tissue repair and reduce death. Our team has completed a Phase I dose escalation and safety clinical trial that evaluated MSCs in patients with septic shock. The Cellular Immunotherapy for Septic Shock Phase I (CISS) trial established that MSCs appear safe and that a randomized controlled trial (RCT) is feasible. Based on these data, the investigators have planned a phase II RCT (UC-CISS II) at several Canadian academic centres which will evaluate intermediate measures of clinical efficacy (primary outcome), as well as biomarkers, safety, clinical outcome measures, and a health economic analysis (secondary outcomes).

Septic shock is a devastating illness and the most severe form of infection seen in the intensive care unit (ICU). It is characterized by cardiovascular collapse, failure of organs and is common with severe repercussions including a mortality of 20-40%. Survivors suffer long-term impairment in function and reduced quality of life (QOL). Despite decades of research examining different immune therapies, none has proven successful and supportive care remains the mainstay of therapy, at a cost of approximately 4-billion dollars in Canada annually. MSCs represent a potentially novel treatment for sepsis because in animal models, MSCs have been shown to modulate the immune system, increase pathogen clearance, restore organ function, and reduce death. The Phase II multi-centre double blind Umbilical Cord Cellular Immunotherapy for Septic Shock RCT (UC-CISS II) will examine intermediate measures of clinical efficacy (primary outcome) as well as biomarkers, safety, clinical outcome measures, and a health economic analysis (secondary outcomes). To answer these aims, UC-CISS II will randomize 296 patients who are admitted to the ICU with septic shock to 300 million cryopreserved, allogeneic, umbilical cord-derived MSCs or placebo across several Canadian academic centres over approximately 2.5 years.