EFFECT OF RECOMBINANT HUMAN THROMBOPOIETIN IN NONHUMAN-PRIMATES WITH CHEMOTHERAPY-INDUCED THROMBOCYTOPENIA

We examined the effects of recombinant human thrombopoietin (rhTPO) on myelosuppressive chemotherapy-induced thrombocytopenia in cynomolgus monkeys, After treatment with nimustine (ACNU) on day 0, tile monkeys intravenously received rhTPO at a dose of 0 . 04, 0 . 2 or 1 mu g/kg/d or monkey's serum once each day from day 1 to day 28. Administration of rhTPO reduced the severity of thrombocytopenia and accelerated the rate of platelet recovery in a dose-dependent fashion, Treatment with the highest rhTPO dose completely prevented thrombocytopenia and stimu lated a marked increase in platelet counts over the normal values. Ani mals treated with ACNU also became neutropenic and slightly anaemic. A dministration of rhTPO following ACNU treatment significantly improved neutropenia with increasing doses of rhTPO, but had no effect on anae mia. Compared to the control animals, rhTPO-treated animals exhibited no significant changes in several serum parameters, C-reactive protein concentration and some blood coagulation profiles within the study pe riod. These results suggest a therapeutic efficacy of rhTPO in improvi ng chemotherapy-induced thrombocytopenia.