A pilot study of rhulL-11 treatment of refractory ITP

The objective of this research was to determine whether rhulL-11 is an effe ctive treatment in patients with refractory immune thrombocytopenic purpura (ITP). platelet production is decreased in certain cases of refractory ITP . IL-11 stimulates megakaryocytopoiesis in vitro and was licensed for its c linical effects to ameliorate chemotherapy-induced thrombocytopenia. A pilo t study was initiated, intending to enroll 12 patients with ITP. These pati ents were to receive rhuIL-11 (Neumega) at a dose of 50 mug/kg subcutaneous ly daily for 21 consecutive days and be observed afterward for 21 additiona l days. CBC with platelets were obtained twice weekly with visits and physi cal examinations weekly. The study was terminated after 7 patients were enr olled because of toxicity and rack of efficacy. All 7 patients had had ITP for >9 years and had failed splenectomy, intravenous gammaglobulin, cortico steroids, and a variety of other treatments. The patients at entry all had platelet counts <20,000/<mu>l; 5 of 7 had counts <10,000/<mu>l. The maximal median increase for any day of the study was 6,000/mul. No patient achieve d a count of 30,000/mul, and only 3 patients achieved (once each) a platele t count >20,000/mul. Substantial toxicity was seen. The nadir hemoglobin de crease was a mean of 2 g/dl. rhuIL-11 was not effective at increasing the p latelet count in any of these patients with refractory ITP, Toxicity was su bstantial. The lack of platelet response to rhuIL-11 in this study does not exclude the possibility of better effects at other doses and/or in less re fractory patients. Am. J, Hematol, 66:172-177, 2001, (C) 2001 Wiley-Liss, I nc.