Clinical efficacy of two different doses of rituximab as a treatment option in adult patients with chronic immune thrombocytopenia

Immune thrombocytopenia (ITP) is an autoimmune bleeding disorder with a high incidence of chronicity among adults. Rituximab is recommended as a treatment option for chronic ITP with the best long-term effect compared with other therapies. However, the optimal dose of rituximab remains unclear. We retrospectively compared the response rate, incidence of relapse, and other clinical outcomes in 34 chronic ITP patients who received rituximab in different doses. Patients were divided into two groups according to rituximab dose (the low-dose group, 100 mg/week for 4 weeks, and the standard-dose group, 375 mg/m² weekly for 4 weeks).

Females represented 72.2% and 56.3% of patients in the low dose and the standard dose groups, respectively. The overall response in all patients was 88.2%. By the end of the second month of treatment, 77.8% achieved partial remission and 11.1% achieved complete remission in the low-dose group versus 68.8% and 18.8% in the standard-dose group. Similar incidence of sustained complete response after 6 months of treatment, 83.3% after low dose rituximab and 81.2% after the standard dose (p = 1.000). The incidence of relapse was similar between both groups.

Our findings demonstrate that both regimens had no statistically significant differences in overall response, relapse rate, and time to reach response. The low dose of rituximab is comparable to the standard high dose in efficacy and safety for the treatment of chronic ITP patients and can be a good option in centers with limited resources.