Abstract: Objective To observe efficacy of avatrombopag (AVA) combined with recombinant human thrombopoietin (rhTPO) on platelet (PLT) engraftment in patients with hematological malignancies after autologous hematopoietic stem cell transplantation (ASCT/auto-HSCT). Methods Seventy-six ASCT patients were retrospectively collected, including 40 patients treated with AVA with rhTPO as observation group, and 36 patients treated with rhTPO alone as control group. PLT count, engraftment time, number of PLT transfused, platelet nadir and duration at grade IV thrombocytopenia were compared, and adverse reactions were recorded. Results The PLT engraftment time in observation group was shorter than that in control group (11.15±1.08 vs.12.61±2.65 days, P<0.05), and the number of PLT transfused units was less [2 (1.00,2.75) units vs. 3 (2.00, 4.00) units], (P<0.001). PLT counts on day 5, day 10 and day 15 in observation group were higher than that in control group, and the rates of platelet engraftment on days 5 and 10 were significantly higher (P<0.05). Multiple linear regression analysis showed that AVA was an independent factor (P<0.001), and its use shortened the engraftment time by 1.598 days. Bleeding events were observed in both groups, mainly in petechiae、ecchymosis or gingival bleeding, and no difference in bleeding rate. No thrombosis and coagulation disorders occurred in both groups. Conclusion AVA combined with rhTPO effectively increased PLT count and promoted PLT engraftment. The combination of the two has a synergistic effect and is well tolerated.

Key words: Autologous hematopoietic stem cell transplantation, Avatrombopag, Chemotherapy-induced thrombocytopenia, Platelet engraftment, Recombinant human thrombopoietin