Real-world predictors of severe chemotherapy-induced neutropenia in non-Hodgkin lymphoma: Evaluation of biosimilar and reference rituximab

BackgroundThe adoption of rituximab biosimilars offers a cost-effective alternative for treating Non-Hodgkin Lymphoma (NHL). However, real-world safety data regarding severe hematological toxicities in the Indonesian clinical setting remains limited.ObjectiveTo evaluate and compare the incidence of severe neutropenia between reference rituximab and its biosimilar in patients with diffuse large B-cell lymphoma (DLBCL) receiving the R-CHOP regimen.MethodsA retrospective cohort study was conducted at a national referral hospital in Jakarta. We included 116 adult patients (Reference group n = 60; Biosimilar group n = 56) who completed six cycles of R-CHOP without product switching between 2019 and 2024. Severe neutropenia was defined as Grade 3 or 4 according to CTCAE criteria. Multivariate logistic regression was performed to identify independent risk factors.ResultsThe overall incidence of severe neutropenia was 62.9%. There was no statistically significant difference in the incidence of severe neutropenia between the reference and biosimilar groups (69.6% vs 56.7%; p = 0.148). Multivariate analysis revealed that male gender was the only independent predictor of severe neutropenia (aOR 2.34; 95% CI 1.05-5.24; p = 0.038), while poor performance status (ECOG ≥ 2) did not reach statistical significance (p = 0.151), regardless of the rituximab product used.ConclusionBiosimilar rituximab demonstrates a comparable safety profile to the reference product regarding severe neutropenia. Clinical monitoring should be prioritized for male patients to mitigate the risk of severe hematological toxicities during R-CHOP therapy.