Manufacturing of Allogeneic Adipose Tissue-derived Mesenchymal Stromal Cells for Treatment of Severe Systemic Sclerosis

Overview

Mesenchymal stromal cells (MSC) are multipotent cells which carry immunomodulatory, pro-angiogenic and anti-fibrotic properties, that can target Systemic Sclerosis (SSc) pathogenesis and its clinical manifestations. The increasing use of MSC, harvested from bone marrow (MSC(M)), adipose tissue (MSC(AT)), or umbilical cord (MSC(UC)) in a variety of indications, provides consistent evidence supporting their safety in humans. The efficacy of MSC(M) intravenous (IV) injection for treating acute graft versus host disease led to their marketing approval in 2012 and MSC(AT) (Alofisel) were approved for severe Crohn's fistula in 2018. MSC represent a promising therapeutic approach for SSc. We previously a) showed disease-specific abnormalities in MSC(M) from SSc patients, providing strong rationale to use allogeneic MSC to treat SSc patients, b) completed the first phase I/II dose escalation trial using allogenic MSC(M) infusion in 20 severe SSc patients (ClinicalTrials.gov: NCT02213705, PHRC AOM 11-250) with no safety issues, significant improvement in skin fibrosis at 3 to 6 months after infusion which appeared lower thereafter, thereby supporting the need for repeated infusions. In vitro, experimental and clinical studies suggest that MSC properties vary according to their tissue of origin/source. We demonstrated that compared to MSC(M), MSC(AT) are easier to harvest and display higher proliferative capability before entering senescence, higher genetic stability, and superior immunosuppressive properties. The objective of the present research is the successful production of allogeneic MSC(AT) derived from selected healthy donors, with adequate phenotypic criteria according to the International Society for Cell \& Gene Therapy. Considering the above rationale, these MSC(AT) will subsequently be used in a Phase I/II randomized clinical trial testing allogeneic MSC(AT) systemic infusion for treatment of severe systemic sclerosis.