Long‐term follow‐up analysis after rituximab salvage therapy in adult patients with immune thrombocytopenia

Abstract

We report the long-term outcome results of 57 consecutive adult patients with immune thrombocytopenia after being treated with rituximab. According to the different period of therapy, patients received either standard dose (SD) rituximab (i.e., 375 mg/m 2 weekly for 4 weeks) or low dose (LD) rituximab (i.e., 100 mg flat dose weekly for 4 weeks). Overall (OR) and complete response (CR) rates were 60 and 40%, respectively. Patients' median follow-up was 52 months, 82 months in the SD, and 44 months in the LD group; 15 out of 34 responsive patients (44%) relapsed, with median response duration of 24 months (range 3-120). The estimated 4-years event-free survival (EFS, considering events the non response status at month 2 or relapses in responders) was 30%. Patients who received SD vs. LD rituximab had better outcome with regard to short term response (OR 66 vs. 52%, CR 50 vs. 28%), relapse rate (38 vs. 54%), probability to achieve and maintain long-term response (41 vs. 24%) and estimated 4-years EFS (35 vs. 23%). Patients with a longer interval between diagnosis and rituximab therapy had worse EFS [HR 5 1.005; 95%IC: (1.002-1.009), P 5 0.019]. Three patients developed short-term adverse events, two-serum sickness, and one interstitial pneumonia. Four cases of malignancies and two herpes zoster reactivations were registered during long-term follow-up; one patient died for cerebral bleeding. Rituximab SD appears a safe and active agent allowing in nearly 40% of cases to achieve long-term response and splenectomy sparing effect. Am. J. Hematol. 87:886-889, 2012. V

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

“…[26][27][28] Once other options became available, e.g. dexamethasone [8][9][10][11][12] and rituximab, [15][16][17][18] the toxicity of cyclophosphamide relegated it to being a tertiary option.…”

“…17 Both rituximab and especially dexamethasone have been shown to be more successful when patients are treated at or very near diagnosis. [9][10][11]15 Two studies then reported the results of the R+1Dex combination. In 2010, one cycle of four days of high-dose dexamethasone followed by four infusions of rituximab was reported to increase the "cure rate" of treatment-naïve patients compared to dexamethasone alone, almost all of whom were treated very close to diagnosis.…”

“…13,14 Rituximab treatment in newly-diagnosed ITP patients appears to be more effective than in patients with persistent or chronic disease. 15 In studies of patients with persistent (3-12 months) and chronic (> 12 months) ITP, approximately 50% of patients experience a strategies to improve the efficacy of rituximab are of value.…”

Autoimmune Cytopenias in Chronic Lymphocytic Leukemia, Facts and Myths

“…The dose of rituximab is 375mg per square meter given weekly for 4 weeks. A lower fixed dose of 100mg per week also has been studied, and has similar response rates 62,63…”

Rituximab Therapy in Adults with Refractory Symptomatic Immune Thrombocytopenia: Long-Term Follow-Up of 15 Cases

“…After a median follow-up of 24 months, 61% showed an overall initial response and 39% had sustained response (SR) [17]. Data on the long-term efficacy of rituximab in adult ITP are limited [13,18,19,20,21]. Several studies reported SR rates ranging from 21% to 40% after a median follow-up period ranging from 2 to 5 years [13,18,19,20,21].…”