Administration of avatrombopag with mesenchymal stem cells (MSCs) improved platelet recovery among patients with prolonged thrombocytopenia after allogeneic hematopoietic stem cell transplant (allo-HSCT), according to the results of a small trial published in the journal Frontiers in Immunology.
This could provide “a new method and strategy for the treatment of thrombocytopenia after all-HSCT,” the authors wrote in their report.
A common complication after allo-HSCT is platelet graft failure, which can cause prolonged thrombocytopenia, in which the platelet count remains lower than 20 x 109/L for more than 3 months. The aim of this study was to evaluate whether the combination of avatrombopag and MSCs could improve thrombocytopenia after allo-HSCT.
The trial treated 16 patients with prolonged thrombocytopenia after allo-HSCT with avatrombopag and MSCs. The avatrombopag dose was based on the platelet count and was discontinued if platelets reached 400 x 109/L. MSCs were administered as an infusion for 4 to 6 weeks.
In the cohort, 10 patients received peripheral blood and bone marrow transplantation and the remaining 6 patients received peripheral blood only. All patients received human granulocyte colony stimulating factor and recombinant human TPO after transplant. All of the patients were in disease remission and none had graft vs host disease, severe infection, or other complications.
There was 100% complete donor engraftment, with a median time to neutrophil recovery of 20.5 days.
Avatrombopag and MSC treatment resulted in a complete response (CR) among 81.3% of patients and 12.5% achieving partial response (PR). The median time to CR was 32 days, and the time to PR was 52 and 230 days for each patient.
There were no thrombotic events and no treatment discontinuation due to adverse drug reactions or intolerance.
The median duration of avatrombopag and MSC administration was 81 days and platelet counts were maintained in all patients who had a response. One patient was treated for 242 days and experienced platelet count fluctuations but did not require transfusion. The 1-year overall survival was 82.5%.
The authors concluded that “overall, our results indicated that combination of avatrombopag with MSCs can promote platelet recovery after transplantation, thereby improving the survival rates of patients and improving quality of life.”
Zhu L, Liu J, Kong P, et al. Analysis of the efficacy and safety of avatrombopag combined with MSCs for the treatment of thrombocytopenia after allogeneic hematopoietic stem cell transplantation. Front Immunol. Published online May 27, 2022. doi: 10.3389/fimmu.2022.910893