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.
Demographics, baseline and follow-up characteristics: descriptive statistics. Primary analysis: Descriptive statistics for the rate of patients with high grade AEs (grade 2 and more), related to the cell implantation will be computed in each arm, with its two-sided 95% CIs. Each dose arm will be compared to the control arm by computing the absolute difference and the relative risk between the active dose arm and the control arm, together with their 95% two-sided CIs. The p-values for the comparisons of the difference between the observed absolute rate to 0 and of the relative risk to 1 will be computed, but it is not expected that the study will have sufficient power to detect a significant difference on either of the two statistics (absolute difference or relative risk). Primary efficacy analysis: The primary efficacy criterion (TcPO2) will be compared between each dose group versus the control group to test for a superiority of MSC over control. The tested hypotheses are: * Null hypothesis: mean (MSC dose i) ≤ mean (Control) * Alternative hypothesis: mean (MSC dose i) \> mean (Control) A mixed - model for repeated measures will be used to model the evolution of TcPO2 over time. The significance of the time by treatment interaction will be used to test the two hypotheses. Model adjusted means (LS means) and their differences between treatment arms will be computed at each timepoint. The LS-Means for change from baseline to 180 days will be used as the primary efficacy endpoint. Other efficacy analyses: the same analysis model (mixed - model for repeated measures) will be used for all the other continuous efficacy endpoints.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
TREATMENT
Masking
NONE
Enrollment
30
Injection of mesenchymal stem cells
Placebo injection
Damien JOLLY
Reims, France
Incidence of treatment - emergent adverse events
The primary safety endpoint will be the occurrence of any high grade AEs (grade 2 and more), either serious or not, assessed as related to the cell implantation by the investigator, reported over the 360 days of the study period. AE Intensity Definition : Grade 1 : asymptomatic or mild symptoms; clinical or diagnostic observations only; intervention not indicated ; Grade 2 : minimal, local or non-invasive intervention indicated; limiting age-appropriate instrumental activities of daily living ; Grade 3 : severe or medically significant but not immediately life-threatening; hospitalization or prolongation of hospitalization indicated; disabling; limiting self-care activities of daily living ; Grade 4 : life-threatening consequences; urgent intervention indicated ; Grade 5 : death related to adverse event
Time frame: Day 1 to day 360
Transcutaneous oxygen pressure
Primary efficacy endpoint: transcutaneous oxygen pressure (TcPO2) mesured in mm Hg
Time frame: Day 360
This platform is for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional.