Cell Therapy in Critical Limb Ischemia

Study drug and dosage form : Umbilical cord-derived mesenchymal stem cells (HB-MSC1) Dose and route of administration : 60 × 106 cells or 120 x 106 cells to be injected as 30 individual intramuscular injections, once at V0 within 48 hours to 2 weeks maximum after the revascularization procedure. Comparator, dose and route of administration : Placebo, injected as 30 individual intramuscular injections, once at V2 within 48 hours to 2 weeks maximum after the revascularization procedure. Study centers : 3 centers in France Study objectives : Primary: Evaluation of the feasibility and systemic and local tolerance of an implantation, via intramuscular route, of allogenic HB-MSC1, associated with a revascularization procedure, in patients suffering from critical limb ischemia (CLI). Secondary: Preliminary evaluation of efficacy and dose effect relationship of the MSC implantation in hemodynamic, anatomical and functional terms. Exploratory: Constitution of a serum bank of the patients included in the study for inflammation and auto immunity biomarkers analysis Study design : This will be a multicenter Phase IIa study, consisting in a first, open-label, ascending dose feasibility and safety stage followed by a randomized placebo-controlled feasibility, safety and preliminary efficacy stage.