A retrospective analysis of response rates and predictors of response to rituximab in management of primary immune thrombocytopenia: Second line and beyond

Objectives: Rituximab is an important second-line option for the treatment of chronic/persistent primary immune thrombocytopenia (ITP). This study aimed to analyze the overall response rates (ORRs) and various factors affecting progression-free survival with rituximab treatment. This can help choose this drug as a second-line option for the best-suited candidates. Material and Methods: We retrospectively analyzed our departmental data of 25 ITP patients treated with rituximab between 2012 and 2020. All patients received rituximab post-first line. Patients with chronic or persistent ITP receiving at least 4 weekly doses of rituximab were included in the study. Patients receiving both low-dose and standard-dose rituximab were included in the study. Results: The median age of patients was 25 years, with a male-female ratio of 1:2. Most patients received rituximab as third-line (56%) or fourth-line (36%) treatment option. Overall, the long-term response rate at a median follow-up of 47.6 months was 60%, while the early response rate at 4 weeks, 8 weeks, and 6 months from the first dose of rituximab was 80%, 60%, and 60%, respectively. Forty per cent of patients could maintain a platelet count >50 × 10 9 /L at 6 months and in the long term. Response at 2 weeks, 4 weeks, early use of rituximab (<12 months), and age >20 years were associated with significantly better progression-free survival. Conclusion: Rituximab is still a very promising option for primary ITP. Short and definite duration of treatment, good safety profile, and impressive ORRs make this agent a viable option for ITP patients in the current era. Response at 2 weeks, 4 weeks, early use of rituximab (<12 months), and age >20 years were associated with significantly better progression-free survival.