Phase II Study of Rituximab in Patients With Immune Thrombocytopenic Purpura

PROTOCOL ENTRY CRITERIA: --Disease Characteristics-- Clinically confirmed immune thrombocytopenic purpura (ITP) Platelet count less than 75,000/mm3 on two occasions at least 1 week apart within past month Normal to increased numbers of megakaryocytes on bone marrow examination within past 6 months Failed prior steroid therapy (i.e., unable to achieve sustained platelet count greater than 75,000/mm3) No drug associated ITP No B cell malignancies No evidence of disseminated intravascular coagulation (DIC) --Prior/Concurrent Therapy-- Endocrine therapy: Concurrent steroids allowed as long as platelet count is less than 75,000/mm3 and dose is not changed within past 2 weeks or during study Other: * No other concurrent medical therapy for immune thrombocytopenia purpura (ITP) * At least 2 weeks since prior therapy for ITP (except steroids) * At least 4 weeks since prior cyclosporine --Patient Characteristics-- Performance status: ECOG 0-2 Life expectancy: At least 6 months Renal: Creatinine no greater than 2.0 mg/dL Cardiovascular: No congestive heart failure or symptomatic coronary insufficiency Other: * No clinically significant bleeding (i.e., other than mild mucosal bleeding or petechiae) * No sepsis or fever * No active infection requiring therapy * No active chronic viral infection * HIV negative * No other concurrent or prior malignancy within past 5 years except squamous or basal cell carcinoma of the skin or carcinoma in situ of the cervix * Not pregnant or nursing * Negative pregnancy test * Fertile patients must use effective contraception