2025 Southeastern Residency Conference

Title: Assessment of Infusion Reaction Rates with Day 1 administration vs Day 5 Administration of Rituximab or biosimilars in Dose-adjusted R-EPOCH
Authors: Xiaoshan Chai, Elena Cukurs, Chynna Bambico, Sarah Gifford

Background
Infusion-related reactions (IRRs) are a significant concern with rituximab, especially when combined with cytotoxic chemotherapy, such as EPOCH (etoposide, prednisone, vincristine, cyclophosphamide, and doxorubicin) for treating B-cell non-Hodgkin lymphomas. Rituximab, a monoclonal antibody targeting CD20 on B-cells, is known to elicit IRRs, including symptoms like fever, chills, and hypotension, particularly during the first infusion. Factors that increase the chance of developing IRRs include bulky disease with high tumor burden, increased cytokine release, and bone marrow involvement. The administration of rituximab for aggressive lymphomas with higher tumor burden further increases the risk of IRRs, necessitating vigilant supportive care to mitigate these reactions effectively. Management strategies involve premedication, titration of infusion rates, and monitoring. One approach to mitigate IRRs is by administering EPOCH first to debulk the tumor mass prior to introducing rituximab.  This study conducted a retrospective chart review to compare the incidences of infusion reactions in B-cell lymphomas patients who received rituximab on either day 1 (D1) or day 5 (D5) of   R-EPOCH from 2022 to 2024.

Methods
A retrospective chart review was conducted on patients over the age of 18 who had not previously received anti-CD20 monoclonal antibodies and had completed at least one cycle of R-EPOCH. Patient records were obtained from the electronic health records (EHR) systems of the oncology departments across sites at AdventHealth Central Florida Division. The primary outcome measured was the incidence of IRRs. Secondary outcomes included incidences of tumor lysis syndrome, types of IRRs, the maximum rate of rituximab infusion achieved, and the average time from the start of infusion to the onset of reactions.

Results
A total of eighty-three patients were included in the IRB-approved study, with 63 qualifying for primary analysis (11 in the D5 group and 52 in the D1 group). The primary endpoint revealed an incidence of IRR of 27.3% (3/11) in the D5 group and 30.8% (16/52) in the D1 group (P = 1). The most common type of infusion related reaction was hypotension in both groups. The median maximum infusion rate was 75 mL/hr in the D5 group and 100 mL/hr in the D1 group. The median time from infusion to the occurrence of IRRs was 110 minutes in the D5 group compared to 75 minutes in the D1 group.

Conclusion
We observed a similar rate of infusion-related reactions between groups. Further analysis will be necessary to confirm these findings and inform the optimal scheduling of rituximab administration within the R-EPOCH regimen.

Assessment Question
Based on the study's findings, which of the following statements best describes the impact of administering rituximab on Day 5 (D5) versus Day 1 (D1) in the R-EPOCH regimen regarding infusion-related reactions (IRRs)?
A. Patients in the D5 group experienced significantly fewer IRRs compared to the D1 group.
B. The incidence of IRRs was similar between the D1 and D5 groups
C. Rituximab infusion rates were lower in the D1 group compared to the D5 group, proving that early administration improves infusion tolerance
D. D1 rituximab administration resulted in less severe IRRs