Allogeneic Mesenchymal Precursor Cells in Type 2 Diabetes: A Randomized, Placebo-Controlled, Dose-Escalation Safety and Tolerability Pilot Study

OBJECTIVE To assess the safety, tolerability, and feasibility of adult allogeneic bone marrow-derived mesenchymal precursor cells (MPCs) in type 2 diabetes inadequately controlled with metformin either alone or with one additional oral antidiabetic agent. RESEARCH DESIGN AND METHODS The study was a dose-escalating randomized placebo-controlled trial assessing one intravenous (IV) infusion of MPCs (rexlemestrocel-L; Mesoblast Inc.) 0.3 x 10(6)/kg (n = 15), 1.0 x 10(6)/kg (n = 15), or 2.0 x 10(6)/kg (n = 15) or placebo (n = 16). Study duration was 12 weeks. RESULTS Subjects (21 women, 40 men) with a mean +/- SD baseline HbA(1c) 8.3 +/- 1.0% (67 +/- 10.9 mmol/mol), BMI 33.5 +/- 5.5 kg/m(2), and diabetes duration 10.1 +/- 6.0 years were enrolled at 18 U.S. sites. No acute adverse events (AEs) were associated with infusion. No serious AEs, serious hypoglycemia AEs, or discontinuations due to AEs over 12 weeks were found. No subjects developed donor-specific anti-HLA antibodies or became sensitized. The safety profilewas comparable among treatment groups. Compared with placebo, a single IV infusion of rexlemestrocel-L reduced HbA(1c) at all time points after week 1. The adjusted least squares mean +/- SE dose-related differences in HbA(1c) from placebo in the rexlemestrocel-L groups ranged from -0.1 +/- 0.2% (-1.1 +/- 2.2 mmol/mol) to -0.4 +/- 0.2% (4.4 +/- 2.2 mmol/mol) at 8 weeks and from 0.0 +/- 0.25% to -0.3 +/- 0.25% (-3.3 +/- -2.7 mmol/mol) at 12 weeks (P < 0.05 for 2.0 x 10(6)/kg dose at 8 weeks). The clinical target HbA(1c) < 7% (53 mmol/mol) was achieved by 33% (5 of 15) of the subjects who received the 2.0 x 10(6)/kg dose vs. 0% of those who received placebo (P < 0.05). CONCLUSIONS This short-term study demonstrates the safety and feasibility of up to 246 million MPCs in subjects with type 2 diabetes.