Immune thrombocytopenia (ITP) is the most common autoimmune hemorrhagic disorder characterized by accelerated platelet destruction and impaired production. Refractory ITP refers to patients who have failed multiple treatments (including thrombopoietin receptor agonists and rituximab) and/or have ineffective or recurrent disease after splenectomy. Such patients have limited responses to existing therapies, often facing significant bleeding risks, severely diminished quality of life, increased mortality rates, and an urgent need for new treatment approaches to address this dilemma. Umbilical cord-derived mesenchymal stem cells (UC-MSCs) possess low immunogenicity and strong immunomodulatory effects, offering potential for new therapies for various autoimmune diseases.
On April 23, Dr. Zhang Lei, Director of the Institute of Hematology at the Chinese Academy of Medical Sciences & Peking Union Medical College (CAMS & PUMC) evaluated, for the first time internationally, the efficacy and safety of UC-MSCs in the prospective treatment of refractory ITP, providing a highly promising new treatment option for patients with refractory ITP. The related research was published in Signal Transduction and Targeted Therapy.
The study, employing a "3+3 dose-escalation" design, prospectively enrolled a total of 18 ITP patients to investigate the safety and efficacy of UC-MSCs in treating refractory ITP. In the dose-escalation phase, 12 ITP patients were sequentially assigned to three dose groups, with UC-MSCs doses of 0.5×10^6 cells/kg (n=3), 1.0×10^6 cells/kg (n=3), and 2.0×10^6 cells/kg (n=6) administered weekly for four consecutive weeks. In the subsequent dose-expansion phase, six ITP patients were treated with a dose of 2.0×10^6 cells/kg weekly for four consecutive weeks. Adverse events, platelet counts, and changes in peripheral blood immune markers were monitored and recorded throughout the administration and follow-up periods.
The results showed that 13 patients experienced one or more adverse events, with four patients experiencing gastrointestinal bleeding, menorrhagia, and acute myocardial infarction, with adverse events graded as level 3 according to the Common Terminology Criteria for Adverse Events (CTCAE). The treatment efficacy rates during the dose-escalation and dose-expansion phases were 41.7% and 50.0%, respectively, with an overall efficacy rate of 44.4%.
Furthermore, the study further evaluated changes in immune function in refractory ITP patients treated with UC-MSCs and explored the potential mechanisms of UC-MSCs in treating ITP. The results indicated that UC-MSCs effectively and safely treated refractory ITP, providing a new treatment option for ITP patients.
Related paper information: https://doi.org/10.1038/s41392-024-01793-5
