Platelet decline rate as the indication of using recombinant human thrombopoietin to prevent chemotherapy induced thrombocytopenia: A prospective, randomized, controlled study.

Abstract

e24171 Background: Doxorubicin combined with ifosfamide is the common regimen for patients with sarcoma, which will induce severe thrombocytopenia. Sarcoma patients especially those with rapid platelet count decline after receiving this regimen could not avoid severe thrombocytopenia, even Recombinant Human Thrombopoietin(rhTPO) was used when the platelet count decreased to 75,000/μL according to current guidelines. The present study aimed to test the efficiency and safety of using rhTPO to prevent severe thrombocytopenia when rapid platelet count decline occurred. Methods: Our previous data showed those patients with rapid platelet count decline more than 40% within 3 days after administration of doxorubicin combined with ifosfamide were more likely to develop severe thrombocytopenia. In this prospective study, 53 patients with this characteristic were randomly assigned to prevention group (starting rhTPO immediately after enrollment) or treatment group (starting rhTPO when platelet count was less than 75,000/μL after chemotherapy). rhTPO was administrated with 300IU/kg·d until the platelet count increased to 100,000/μL or by 50,000/μL. Incidence and duration of grade 3 to 4 thrombocytopenia, proportion of platelet transfusion and adverse reactions were collected and analyzed. Results: The incidence of grade 3 to 4 thrombocytopenia in the prevention group and the treatment group was 63% and 81% respectively (p = 0.224), however the incidence of grade 4 thrombocytopenia in the former was significantly lower than that in the latter(22% versus 50% , p = 0.047).The duration of grade 3 to 4 thrombocytopenia in the prevention group had a declining trend compared with the treatment group( 2.6±2.8d versus 3.7±3.3d, p = 0.198). There was no difference in the proportion of platelet transfusion between the two groups. No rhTPO related toxicities of grade 3 to 4 were observed in both groups. Conclusions: For sarcoma patients treated with doxorubicin combined with ifosfamide, rapid platelet count decline more than 40% within 3 days after chemotherapy can be used as an indicator for the prophylactic administration of rhTPO, which can significantly reduce the probability of grade 4 thrombocytopenia without increasing toxicity. Clinical trial information: ChiCTR1900022667 .