OBJECTIVEThis phase II clinical trial was designed to evaluate the efficacy and toxicity of recombinant human interleukin-11 (rhIL-11) derivative manufactured in China in the prevention and treatment of chemotherapy-induced thrombocytopenia in cancer patients.

METHODSA total of 100 cancer patients with chemotherapy-induced thrombocytopenia (< or = 75 x 10(9)/L) were studied by self-cross control. Ninty-one of them received 2 cycles of chemotherapy. In the first cycle (control cycle) the patients received chemotherapy only, while in the second cycle (treatment cycle), the patients were given subcutaneous injection of rhIL-11 derivative (40 microg.kg(-1).d(-1)) once daily after chemotherapy for 10 consecutive days or more until platelet count reached > or = 300 x 10(9)/L.

RESULTS1. The patients with platelet count of < or = 75 x 10(9)/L was 89/89 in the control cycle and 44/89 in the treatment cycle (P = 0.00). The recovery time to the normal platelet count was 1-47 days (median 9 days) in the control cycle, and 1-18 days (median 5.5 days) in treatment cycle (P = 0.00). 2. Patients with platelet count of < or = 50 x 10(9)/L was 56/89 in the control cycle and 20/89 in the treatment cycle (P = 0.00). The recovery time to normal platelet count was 1-31 days (median 9 days) in the control cycle and 3-13 days (median 6 days) in the treatment cycle (P = 0.05). 3. The median nadir platelet count was 44 x 10(9)/L (range: 10 x 10(9)/L-75 x 10(9)/L) in the control cycle, and 83 x 10(9)/L (range: 10 x 10(9)/L-310 x 10(9)/L) in the treatment cycle (P = 0.00). The time of recovery to the normal platelet count was 1-31 days (median 6 days) in the control cycle, and 0-13 days (median 2 days) in the treatment cycle (P = 0.00). 4. Nine of 89 evaluable patients required platelet transfusion in the control cycle versus 1 of 89 patients in treatment cycle (P = 0.01), and the total platelet transfusion was 10 times in the control cycle versus once in the treatment cycle (P = 0.01). 5. The major adverse events associated with rhIL-11 derivative were: headache, fatigue, myalgia/arthralgia, edema and palpitation, etc.

CONCLUSIONrhIL-11 derivative can be safely and effectively used for the prevention and treatment for chemotherapy-induced thrombocytopenia.