Clinical efficacy of rhIL-11.

Placebo-controlled clinical trials of recombinant human interleukin-11 (rhIL-11, also known as oprelvekin [Neumega]) in patients with nonmyeloid malignancies have demonstrated significant efficacy in preventing postchemotherapy platelet nadirs of < or = 20,000/microL, and reducing the need for platelet transfusions while continuing chemotherapy without dose reductions. The likelihood of requiring a platelet transfusion in rhIL-11-treated patients receiving chemotherapy is approximately 40% lower than the risk for untreated patients. Treatment with rhIL-11 appears to accelerate earlier recovery to platelet counts of 20,000/microL, 50,000/microL, and 100,000/microL, suggesting that patients treated with rhIL-11 are more likely to be able to receive their next chemotherapy cycle in a timely fashion. rhIL-11 shows sustained efficacy over multiple cycles of full-dose chemotherapy. Activity has also been demonstrated in pediatric patients with solid tumors. The use of rhIL-11 in combination with granulocyte colony-stimulating factor (G-CSF, filgrastim [Neupogen]) may also produce a synergistic hematopoietic effect, resulting in earlier neutrophil recovery. The recommended adult dose regimen for rhIL-11 is 50 micrograms/kg administered subcutaneously once daily beginning 6 to 24 hours after the administration of chemotherapy until a postnadir platelet count of > or = 50,000/microL is reached. The recommended pediatric dose of rhIL-11 is 75 micrograms/kg subcutaneously, once daily beginning 6 to 24 hours after the administration of chemotherapy until a postnadir platelet count of > or = 50,000/microL is reached. The administration of rhIL-11 for greater than 21 days has not been studied and therefore is not recommended.