Umbilical Cord-Derived Mesenchymal Stromal Cells (MSCs) for Knee Osteoarthritis: Repeated MSC Dosing Is Superior to a Single MSC Dose and to Hyaluronic Acid in a Controlled Randomized Phase I/II Trial

Matas J, Orrego M, Amenabar D, et al. · Stem Cells Translational Medicine

At 12 months the repeated-dose arm sat lower than HA on WOMAC pain (1.1 +/- 1.3 vs 4.3 +/- 3.5, p=.04), on total WOMAC (4.2 +/- 3.9 vs 15.2 +/- 11, p=.05) and on VAS (2.4 +/- 2.1 vs 22.1 +/- 9.8, p=.03). The function subscale, SF-36 and every MRI score showed no difference between the groups. Each cell arm was measured against HA and the two were never measured against each other - the discussion describes the design as comparing single against double dosing with respect to HA administration - so the superiority over a single dose that the title asserts is claimed by neither the results, the discussion nor the conclusion. OARSI responder status reached 100% on repeated dosing against 62% on HA, which did not separate (p=.08).

Population

26 patients with symptomatic knee OA (HA 8, single MSC dose 9, repeated MSC dose 9)

Intervention

Allogeneic umbilical cord-derived MSCs, single dose or repeated at 6 months

Comparator

Hyaluronic acid at baseline and 6 months

Limitations

Eight to nine patients per arm with mild-to-moderate disease and low radiological involvement, which the authors name as the trial's main limitation; randomized and triple-blind. Seven authors declare employment or a leadership position with Cells for Cells, the manufacturer, one of them also holding intellectual property in it. No serious adverse events, deaths or septic arthritis; transient knee effusion ran more often on cells than on HA (33% against 22% after the first injection, p=.99). The active comparator is itself a near-placebo intervention.