Long-term efficacy and safety of low-dose rituximab in immune thrombocytopenia: a multicentre, prospective, open-label, randomised controlled trial

Around 60–80% of patients with immune thrombocytopenia (ITP) experience disease relapse after stopping corticosteroids. Rituximab (RTX) is an effective second-line treatment. Low-dose RTX has shown similar efficacy to standard dose, but the optimal dosage remains uncertain. This multicentre, prospective, open-label, randomised controlled trial aimed to compare the long-term efficacy (5-year follow-up) and 1-year safety of two low-dose RTX regimens in Chinese adult patients with glucocorticoid-resistant/dependent or relapsed ITP. Patients (n = 104) were randomised 1:1 to group A (RTX 100 mg weekly for 4 weeks) or group B (RTX 375 mg/m2 once). The primary outcome was overall response (OR) at 3 months after RTX initiation. Response was followed up until disease relapse or for 5 years. Forty-nine patients in Group A and 51 patients in Group B completed the intervention. At 3 months after RTX initiation, 32 patients in group A (65.3%) and 33 patients in group B (64.7%) achieved OR, and the complete response rate was 42.9% (21/49) in group A and 39.2% (20/51) in group B. The sustained response rates at 6 months, 1, 2, and 5 years were 59.2%, 42.9%, 28.6%, and 20.4% in group A and 58.8%, 43.1%, 33.3%, and 17.6% in group B. These variables were not statistically different between two groups. The most common adverse events were upper respiratory tract and pulmonary infections. RTX 375mg/m2 once showed similar long-term efficacy compared to RTX 100 mg weekly for 4 weeks, with a comparable 1-year safety profile; both being well tolerated. The single-dose regimen may be preferable due to greater patient convenience and reduced economic burden. Trial registration ClinicalTrials.gov Identifier- NCT01719692 (Registration date: October 26, 2012).