Cytokine in cancer chemotherapy--clinical trials of IL-3, IL-11 and thrombopoietin against thrombocytopenia

Clinical trials of IL-3, IL-11 and thrombopoietin (TPO) against chemotherapy-induced thrombocytopenia were reviewed. Many clinical trials of IL-3 were conducted, which increased the platelet nadir counts and improved the recovery from thrombocytopenia at a dose of 5 micrograms/kg/day for 7 to 14 days. Major side effects, fever and headache, were tolerable. The combination with G-CSF was also examined. IL-11 improved the platelet nadir counts and the recovery from thrombocytopenia at a dose of 50 micrograms/kg/day for 14 days. Adverse events of IL-11 were general fatigue and edema, which were mild. Phase I/II studies of TPO were conducted, which showed a marked increase of platelet counts and improvement in recovery from thrombocytopenia. A few patients experienced mild thrombo-embolism. Improved QOL and survival benefits in the evaluation of these cytokines must be demonstrated.