Intra-articular delivery of allogeneic bone marrow derived mesenchymal stromal cells (BM-MSCs) for painful lumbar facet arthropathy: a phase I clinical trial.

IMPORTANCE

Lumbar facet arthropathy (LFA) is one of the most common specific disorders associated with low back pain. Current treatments provide only symptomatic relief and are often limited in their long-term effectiveness.

OBJECTIVE

To evaluate the safety and preliminary efficacy of intra-articular delivery of allogeneic BM-MSCs in patients with painful LFA.

DESIGN, SETTING, AND

PARTICIPANTS

This study was a prospective, Phase I, single-arm, open-label clinical trial. Ten patients with painful LFA were enrolled with nine completing the 2-year follow-up.

INTERVENTIONS: All patients received a single intra-articular administration into two affected lumbar facet joints, with each joint injected 10 million allogeneic BM-MSCs suspended in 1 mL Lactated Ringer's solution.

MAIN OUTCOMES AND MEASURES: The primary endpoint was safety, as reflected by adverse events (AEs). Secondary endpoints (and the assessment tools) included low back pain (VAS), physical function (PROMIS CAT Physical Function), health status (PROMIS CATs), and the severity of facet joint degeneration on MRIs. The minimum clinically important difference (MCID) thresholds in this trial were pre-defined as a 50% reduction in low back pain (VAS), or an increase of 2.3 points on the PROMIS CAT Physical Function.

RESULTS

The procedures were well tolerated. There were no clinical signs of immune reaction to the allogeneic BM-MSCs. No study-related serious AEs were observed. Six patients achieved the MCID on VAS for pain at 6-, 12-, 18-, and 24-month follow-ups and five patients consistently met MCID for the PROMIS CAT Physical Function across all follow-up visits. MRIs showed reduced facet joint degeneration at one or more levels in five patients.

CONCLUSIONS AND RELEVANCE: This study demonstrated a favorable safety profile for intra-articular delivery of BM-MSCs for painful LFA. Preliminary therapeutic benefits were observed, including back pain relief, improved physical function, and reduced facet joint degeneration. Further larger, randomized clinical trials are warranted to further assess its safety and efficacy. Trial Registration ClinicalTrials.gov Identifier: NCT04410731.