TOPLINE:

Compared with an injection of saline placebo, a single intra-articular injection of autologous adipose-derived mesenchymal stromal cells showed no significant improvement in pain or function scores in patients with mild-to-moderate knee osteoarthritis (OA). The treatment was well tolerated with minor and transient adverse events.

METHODOLOGY:

• Researchers conducted a phase 2b randomized controlled trial to assess the efficacy of an intra-articular injection of autologous adipose-derived mesenchymal stromal cells in adults with mild-to-moderate knee OA.
• A total of 135 patients aged 45-70 years were enrolled across nine clinical centers in the Europe from September 2016 to March 2022; 97 patients who received the treatment were analyzed.
• Patients were randomly assigned to receive a single ultrasound-guided intra-articular injection of either low-dose (2 × 10⁶ cells; n = 30) or high-dose (10 × 10⁶ cells; n = 25) adipose-derived mesenchymal stromal cells or saline placebo (n = 42). Liposuction was performed for preparation of autologous cells in those receiving these cells, and sham liposuction was performed in the placebo arm.
• The primary endpoint was the rate of “strict responders” at 6 months after injection, defined by the OsteoArthritis Research Society International/Outcome Measures in Rheumatology criteria as having at least a 50% improvement from baseline and a minimum absolute change of ≥ 20 mm in pain and physical function scores on the Western Ontario and McMaster Universities Osteoarthritis Index.
• Secondary outcomes included self-reported pain, physical function, and quality of life assessed over a 12-month follow-up period, along with MRI-based cartilage thickness and safety measures.

TAKEAWAY:

• At 6 months, 47.3% of patients who received adipose-derived mesenchymal stromal cells and 54.8% of those who received placebo were strict responders, with no significant differences between the low-dose and placebo groups or between the high-dose and placebo groups.
• Secondary outcomes, including changes in knee pain intensity and quality of life, were not significantly different between the treated and placebo groups at various timepoints over 12 months.
• Changes in cartilage thickness were not significantly different between treatment groups over the 12-month period.
• Adverse events were minor and transient, with similar incidence rates among the three groups: 92.3% of those who received high-dose cells, 90.3% of those who received low-dose cells, and 85.7% of those who received placebo experienced at least one adverse event.

IN PRACTICE:

“[The study] findings do not support the use of a single autologous ADSC [adipose-derived stem cell] injection for the management of knee OA,” the authors wrote.

SOURCE:

This study was led by Yves-Marie Pers, MD, PhD, University of Montpellier, INSERM, CHU Montpellier, Montpellier, France. It was published online on August 29, 2025, in Annals of the Rheumatic Diseases.

LIMITATIONS:

The high response rate owing to blinding may have limited the ability to achieve the primary endpoint. The sample size was insufficient.

DISCLOSURES:

This study was funded by the European Union’s Horizon 2020 research and innovation program and sponsored by CHU Montpellier. Authors acknowledged support from ECELLFrance, the national research infrastructure for regenerative medicine, and Immun4-Cure IHU Institute for innovative immunotherapies in autoimmune diseases. Two authors were supported by Versus Arthritis and the National Institute for Health and Care Research Cambridge Biomedical Research Centre. One author reported receiving financial support from the European Union’s Horizon 2020 program, and another author from ECELLFrance.

This article was created using several editorial tools, including AI, as part of the process. Human editors reviewed this content before publication.