Objective: To evaluate the efficacy and safety of recombinant human thrombopoietin (rhTPO) on chemotherapy-induced severe thrombocytopenia.
Methods: In this self-controlled multi-center clinical trial, 81 patients, 23 with solid tumor and 58 with leukemia with complete remission, with the platelet count < or = 20 x 10(9)/L after chemotherapy were given two cycles of the same chemotherapy. The first cycle was non- rhTPO-treated cycle as control, in the second cycle rhTPO of the dosage of 1.0 microg.kg(-1).d(-1) was administered subcutaneously 6-24 hours after the beginning of chemotherapy for at most 14 days. Laboratory tests including complete blood counts, urinalysis, serum chemistry, coagulant test, chest radiography, and electrocardiography were made. Serum samples were screened for anti-rhTPO antibodies.
Results: In rhTPO-treated cycle, the platelet count was higher [the mean minimal platelet count was 13 x 10(9)/L, significantly higher than that of the control cycle (12 x 10(9)/L, P = 0.002), the mean maximal platelet count was 186 x 10(9) cells/L, significantly higher than that of the control cycle (122 x 10(9)/L, P < 0.001)]. The duration of thrombocytopenia was shorter in the rhTPO-treated cycle than in the control cycle: days with platelet count <50 x 10(9)/L, days with platelet count recovered > or = 75 x 10(9)/L, and days with platelet count recovered > or = 100 x 10(9)/L were 11 days, 21 days, and 24 days respectively, all significantly shorter than those of the control cycle (13 days, 24 days, and 27 days respectively, P < 0.05, P < 0.001, and P < 0.001). The amount of needed platelet transfusion was 10 U in the rhTPO-treated cycle, both significantly less than those in the control cycle (12 U, P < 0.001). No effects of rhTPO on hemoglobin, white blood cells, hepatic function, kidney function and coagulant function were found. Transient low-titer antibody was developed in one patient. Side effects such as fever, knee arthralgia, dizziness, headache and chill were mild and tolerable.
Conclusion: Administration of rhTPO after chemotherapy significantly reduces the degree and duration of thrombocytopenia and the need for platelet transfusions.