Efficacy and safety of hetrombopag in the treatment of recombinant human thrombopoietin-resistant thrombocytopenia after allogeneic hematopoietic stem cell transplantation.

Abstract

BackgroundThrombocytopenia after allogeneic hematopoietic cell transplantation is a challenging clinical problem. Recombinant human TPO (rhTPO) and TPO receptor agonists (TPO-RA) are increasingly used in post-transplant thrombocytopenia. However, the use of hetrombopag in patients with post-transplant thrombocytopenia, especially in patients with resistance to rhTPO, has not yet been reported. Objectives: The present study aimed to investigate the efficacy and safety of hetrombopag in patients with rhTPO-resistant post-transplant thrombocytopenia. Methods: The retrospective study included 21 patients with rhTPO-resistant post-transplant thrombocytopenia who received hetrombopag from August 2021 to July 2022. The primary endpoint was the overall response rate (ORR), including partial response (PR) and complete response (CR). We also evaluated the predictors of hetrombopag efficacy and adverse events. Results: The ORR to hetrombopag was 81% and the CR rate was 62%. The median time from hetrombopag initiation to response and CR were 16 and 31 days, respectively. Decreased megakaryocytes in bone marrow negatively correlated with CR to hetrombopag (p=0.027). All the patients tolerated hetrombopag well without any significant increase in adverse events. At the last follow-up, 71% of responders had discontinued hetrombopag and sustained their best response. Conclusion: Our results suggested that hetrombopag is an effective treatment option to promote platelet recovery in patients with post-transplant thrombocytopenia, even in patients resistant to rhTPO.