Romiplostim for thrombocytopenia following allogeneic stem cell transplantation: A case series

Thrombocytopenia is a relatively common complication following allogeneic hematopoietic stem cell transplantation and is associated with increased bleeding, transfusion requirements, chronic graft-versus-host disease, and all-cause mortality. There are currently no approved treatments outside of supportive transfusions. We report on the outcomes of five patients at our institution who received romiplostim for either primary engraftment failure or secondary failure of platelet recovery following stem cell transplantation. In total, four out of the five patients demonstrated a response to romiplostim, which was defined as seven consecutive days of platelet count >50 × 10⁹/L with transfusion independence, with two ongoing responses (>365 days each) at the conclusion of the study period. Responses to romiplostim were sustained in the absence of significant bone marrow disease, which was found to contribute to recurrent thrombocytopenia. Additionally, romiplostim was well-tolerated overall; one patient developed minimal fibrotic changes on bone marrow biopsy postromiplostim. Although these results are promising, data from randomized clinical trials are needed to fully understand the role of romiplostim after stem cell transplantation.