Long-term Safety and Efficacy of Mesenchymal Stem Cell Therapy in Severe COVID-19 Patients

Background The study aimed to evaluate the long-term safety and efficacy of mesenchymal stem cell (MSC) therapy in severe COVID-19 patients, following a previous randomized, double-blind, placebo-controlled clinical trial. The focus was on assessing outcomes over a 2-year follow-up period.

Methods A total of 100 severe COVID-19 patients were enrolled, with 65 receiving MSC treatment and 35 receiving a placebo, combined with standard care. The treatment was administered on days 0, 3, and 6. Patients were evaluated at 18 and 24 months post-treatment for various outcomes, including 6-MWD, lung imaging, quality of life (SF-36 questionnaire), COVID-19-related symptoms, titers of SARS-CoV-2 neutralizing antibodies, and MSC-related adverse events.

Results

• 6-MWD: A marginally smaller proportion of patients in the MSC group had a 6-MWD below the lower limit of the normal range at month 24 compared to the placebo group.
• Quality of Life: The MSC group showed a higher general health score on the SF-36 questionnaire at month 18.
• Lung Imaging and Neutralizing Antibodies: No significant differences were observed between the MSC and placebo groups at months 18 and 24.
• Safety: No MSC-related adverse events were reported during the 2-year follow-up period.

Conclusion The study concludes that MSC treatment is safe over a 24-month period but does not show significant sustained efficacy in severe COVID-19 patients. The findings underscore the need for further research, including larger phase 3 clinical trials, to determine the efficacy of MSC therapy for COVID-19 and other types of pneumonia.