Examining the adverse event potential of rituximab

For children who require immunotherapy, rituximab is a frequent choice. Are there any adverse events linked to using it? An investigation in JAMA Network Open offers some information.¹

The researchers ran a retrospective cohort study of patients aged younger than 21 years who were given at least 1 dose of rituximab for a variety of indications. Patients who were getting immunotherapy for hematopoietic stem cell or solid organ transplant, were using other lymphodepleting therapy, or had primary immunodeficiencies were excluded from the study. They noted adverse drug events such as anaphylaxis during a treatment course, which was at least 1 dose of rituximab with less than a month between doses, the incidence of mild and severe infections, and the time to the recovery of B lymphocyte subset counts and immunoglobulin levels.

A total of 468 patients who had received at least 1 dose of rituximab and did not meet the exclusion criteria were found. They were followed up for a total of 11,713 person-months. Adverse events linked to a rituximab infusion were found in 72 of the patients and 17 patients experienced anaphylaxis. Long-term adverse events like leukoencephalopathy and prolonged neutropenia were not found. Two hundred twenty-four of the patients had infections, with 84 having a severe infection and 3 contracting a lethal infection. An increased infection link was tied to concurrent use of intravenous immunoglobulin, treatment of systemic lupus erythematosus, neutropenia, and intravenous chemotherapy. A total of 135 patients were followed up to B cell count recovery and CD19+ or CD20+ cell numbers were normalized in a median of 9.0 months after rituximab use. Additionally, 48 of 95 patients who had evaluations beyond a year were found to have low-for-age B cell counts. The recovery of CD27+ memory B cell number were found to occur in a median of 15.7 months. For patients who had a normal baseline value, low levels of immunoglobulin G occurred in 67 of 289 patients and low levels of immunoglobulin occurred in 118 of 255 patients. For the patients who were evaluated beyond 12 months, 16 of 117 had persistently low immunoglobulin G and 37 of 109 had persistently low immunoglobulin M.

The researchers concluded that rituximab is well-tolerated in pediatric patients and is not linked to many serious adverse events. However, infections are common among patients treated with it, which is linked to a prolonged period of B cell count recovery. They urged further study to find strategies to prevent infections following the administration of rituximab.

Reference

1. McAtee C, Lubega J, Underbrink K, et al. Association of rituximab use with adverse events in children, adolescents, and young adults. JAMA Netw Open. 2021;4(2):e2036321. doi:10.1001/jamanetworkopen.2020.36321