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 may 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 mesenchymal stem cells (MSCs) in patients with septic shock. The Cellular Immunotherapy for Septic Shock (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 (CISS2) at several Canadian academic centres which will evaluate safety, signals for clinical efficacy, and continue to examine potential mechanisms of action and biological effects of MSCs in septic shock.

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 Cellular Immunotherapy for Septic Shock RCT (CISS2) will continue to evaluate safety, assess if there are signals for clinical efficacy and determine mechanisms of action and biological effects of MSCs in septic shock. To answer these aims, CISS2 will randomize 114 patients who are admitted to the ICU with septic shock to 300 million cryopreserved, allogeneic, bone marrow derived MSCs or placebo across 10 Canadian centres over approximately 2 years.