Rituximab and three dexamethasone cycles provide responses similar to splenectomy in women and those with immune thrombocytopenia of less than two years duration

Abstract

Adults with newly diagnosed or persistent immunothrombocytopenia frequently relapse upon tapering steroids; adults and children with chronic disease have an even lower likelihood of lasting response. In adults with newly-diagnosed immunothrombocytopenia, two studies showed that dexamethasone 40 mg/day × four days and 4 rituximab infusions were superior to dexamethasone alone. Studies have also shown three cycles of dexamethasone are better than one and patients with persistent/chronic immunothrombocytopenia respond less well to either dexamethasone or rituximab. Therefore, 375 mg/m² × 4 rituximab was combined with three 4-day cycles of 28 mg/m² (max. 40 mg) dexamethasone at 2-week intervals and explored in 67 ITP patients. Best long-term response was assessed as complete (platelet count ≥100×10⁹/L) or partial (50–99×10⁹/L). Only 5 patients had not been previously treated. Fifty achieved complete (n=43, 64%) or partial (n=7, 10%) responses. Thirty-five of 50 responders maintained treatment-free platelet counts over 50×10⁹/L at a median 17 months (range 4–67) projecting 44% event-free survival. Duration of immunothrombocytopenia less than 24 months, achieving complete responses, and being female were associated with better long-term response (Pclinicaltrials.gov identifier:02050581)