Safety and efficacy of an allogeneic adipose-derived mesenchymal stem cell preparation in the treatment of knee osteoarthritis: A Phase I/IIa randomised controlled trial

Objectives: To assess the safety and efficacy of an allogeneic adipose-derived mesenchymal stem cell preparation (MAG200) in the treatment of knee osteoarthritis over 12 months.

Design: A single-centre, double-blind, ascending dose, randomised controlled trial. 40 participants with moderate knee osteoarthritis were randomised to receive a single intra-articular injection of MAG200 (dose cohorts:10, 20, 50, 100 ​× ​10⁶ ​cells) or placebo. Primary objectives were safety and efficacy according to a compound responder analysis of minimal clinically important difference in pain (numerical pain rating scale [NPRS]) and function (Knee Injury and Osteoarthritis Outcome Score - Function in Daily Living subscale [KOOS_ADL]) at month 12. Secondary efficacy outcomes included changes from baseline in patient reported outcome measures and evaluation of disease-modification using quantitative MRI.

Results: Treatment was well tolerated with no treatment-related serious adverse events. MAG200 cohorts reported a greater proportion of responders than placebo and demonstrated clinical and statistically significant improvement in pain and clinically relevant improvement in all KOOS subscales. MAG200 demonstrated a reproducible treatment effect over placebo, which was clinically relevant for pain in the 10 ​× ​10⁶ dose cohort (mean difference NPRS:-2.25[95%CI:-4.47,-0.03, p ​= ​0.0468]) and for function in the 20 ​× ​10⁶ and 100 ​× ​10⁶ dose cohorts (mean difference KOOS_ADL:10.12[95%CI:-1.51,21.76, p ​= ​0.0863] and 10.81[95%CI:-1.42,23.04, p ​= ​0.0810] respectively). A trend in disease-modification was observed with improvement in total knee cartilage volume in MAG200 10, 20, and 100 ​× ​10⁶ dose cohorts, with progression of osteoarthritis in placebo, though this was not statistically significant. No clear dose response was observed.

Conclusion: This early-phase study provides supportive safety and efficacy evidence to progress MAG200 to later-stage trial development.

Trial registration: ACTRN12617001095358/ACTRN12621000622808.