Physicochemical Stability of the Rituximab Biosimilar ABP 798 in Intravenous Bags Following Preparation and Storage

Introduction: ABP 798 (rituximab-arrx, RIABNI ® ) is a biosimilar to rituximab available as a sterile, preservative-free solution (10 mg/mL) in a single-use vial for intravenous (IV) infusion. The purpose of this study was to assess the physicochemical stability of ABP 798 after dilution with 0.9% (w/v) saline or 5% (w/v) dextrose. Methods: Two experimental arms designated “preliminary hold” and “optimized storage condition” were assessed. For both arms, ABP 798 was diluted to 1 and 4 mg/mL with sterile 0.9% (w/v) saline or 5% (w/v) dextrose in IV bags. For the preliminary hold assessment, the IV bags were kept at 2°C to 8°C for up to 30 days, followed by storage at 30°C for 24 hours (h), and then infusion at ambient temperature. For the optimized storage condition assessment, the IV bags were kept at 2°C to 8°C for up to 30 days (saline-diluted) or up to 24 hours (dextrose-diluted), followed by storage at 30°C (saline-diluted) or 25°C (dextrose-diluted) for 24 hours and infusion at two different infusion rates. Samples collected at different time points were evaluated for various product quality attributes. Results: Saline-diluted ABP 798 was physicochemically stable after 30 days of storage at 2°C to 8°C followed by storage at 30°C for 24 hours, and then infusion, as determined by the absence of changes to quality attributes. Degradation was observed in dextrose-diluted ABP 798 after 30 days of storage at 2°C to 8°C followed by 24 hours storage at 30°C. Dextrose-diluted ABP 798 remained physicochemically stable after 24 hours storage at 2°C to 8°C followed by 24 hours at 25°C. Conclusions: These results indicate that ABP 798 remains chemically and physically stable when diluted in IV bags with 0.9% (w/v) saline stored at 2°C to 8°C for 30 days or 5% (w/v) dextrose stored at 2°C to 8°C for 1 day. Overall, these findings provide strong evidence supporting the chemical and physical stability of ABP 798 under the tested conditions. It is essential for the end-user to ensure the overall quality of the prepared admixture by strictly adhering to the product’s packaging insert instructions.