A randomized placebo-controlled trial of recombinant human interleukin-11 in cancer patients with severe thrombocytopenia due to chemotherapy

Thrombocytopenia is a complication of cancer treatment that can limit dose intensity. Interleukin-11 (IL-11) is a growth factor that increases platelet production. We conducted a multicenter, randomized, placebo-controlled trial of recombinant human IL-11 (rhIL-11) in 93 patients with cancer who had already been transfused platelets for severe thrombocytopenia resulting from chemotherapy. The patients had received platelet transfusions for nadir platelet counts of ≤20,000/μL during the chemotherapy cycle immediately preceding study entry. Chemotherapy was continued during the study without dose reduction. Patients were randomized to receive placebo or rhIL-11 at 50 or 25 μg/kg subcutaneously once daily for 14 to 21 days beginning 1 day after chemotherapy. Eight of 27 (30%) evaluable patients treated with rhIL- 11 at a dose of 50 μg/kg did not require platelet transfusions versus 1 of 27 (4%) patients who received placebo (P < .05). Five of 28 (18%) patients treated with rhIL-11 at 25 μg/kg avoided platelet transfusions (P = .23). Side effects were fatigue and cardiovascular symptoms, including a low incidence of atrial arrhythmias and syncope. There were no differences among treatment groups in the incidence of neutropenic fever, days of hospitalization, or number of red blood cell transfusions. This study shows that rhIL-11 treatment at a dose of 50 μg/kg significantly increases the likelihood that patients who have already been transfused platelets for severe chemotherapy-induced thrombocytopenia will not require platelet transfusions during a subsequent chemotherapy cycle.