EFFICACY AND SAFETY OF TWO DIFFERENT LOW-DOSE RITUXIMAB REGIMENS FOR CHINESE CHILDREN PATIENTS WITH PRIMARY IMMUNE THROMBOCYTOPENIA

ABSTRACT

Background: Rituximab is one of the second-line treatments for ITP. At present, there are few studies on low-dose rituximab, lacking of a large number of prospective and randomized trials to support the efficacy and safety of lowdose rituximab, especially in children's ITP. Influenced by COVID-19, we used two low-dose rituximab regimens before and after March 2020 for second-line treatment of children's ITP. Aims: To compare the efficacy and safety of two different regimens for low-dose rituximab of children patients with chronic /refractory ITP, so as to provide basis for clinical treatment. Methods: 83 children patients were enrolled in this study and non-randomly assigned to receive 100mg/200mg (body weight 30kg) rituximab weekly for 4 weeks (group A, 53 cases) or a single dose of 375mg / m2 rituximab (group B, 30cases). The study was follow-up for at least half a year. Results: The baseline data of group A and B were the same. For group A Overall and complete response (OR and CR) rates were 35.8% and 15%, respectively;the side effects rate is 3.8%. In responders, the median time to response was 4 (1 -12) weeks, with a median follow-up time of 12 (6 ∼ 36) months, 6 of 19 responders (31.6%) relapsed. For group B OR and CR rates were 36.7% and 23%, respectively;the side effects rate is 10%. In responders, the median time to response was 1 (1 ∼ 4) weeks, with a median follow-up time of 11.5 (6 ∼ 17) months, 4 of 11 responders (36.4%) relapsed. No significant difference in the OR, NR, relapse free survival and incidence of side effects was observed in patients between the two groups. Image Summary/Conclusion: The two low-dose rituximab regimens in the treatment of ITP in children both are safe and effective;The single-agent scheme is more recommended because of easier use and not increasing safety events.