In-Use Stability of the Rituximab Biosimilar CT-P10 (Truxima) Following Preparation for Intravenous Infusion and Storage.

BACKGROUND

CT-P10 is the first biosimilar of the anti-CD20 monoclonal antibody, rituximab. CT-P10 is currently available in over 51 countries worldwide, where it is approved in the same indications as its reference product rituximab. In-use stability studies are conducted for biologics to determine how conditions (e.g., temperature, light, humidity, length of time stored) affect drug quality following dilution and storage in infusion bags.

OBJECTIVE

We evaluated the in-use stability of CT-P10 for intravenous infusion stored diluted in infusion bags over longer periods than currently recommended by manufacturer guidelines.

METHODS

CT-P10, within the final month of its 36-month shelf life, was diluted to 1.0 or 4.0 mg/mL and stored at 2-8 °C in polyethylene or polyvinylchloride infusion bags for 2, 4, and 6 weeks. CT-P10 infusion bags were incubated at room temperature for 24 h before analysis. Analyses included detection of sub-visible particles, formation of impurities and determination of charge variants, and heavy- and light-chain content. Cell-based CD20 binding affinity and complement-dependent cytotoxicity were also assessed.

RESULTS

Diluted CT-P10 solutions remained clear, colorless, and free of visible particles irrespective of type of infusion bag, target concentration, or timepoint. Protein concentrations, sub-visible particles, pH, osmolality, and molecular weight and charge variants were stable across all timepoints and variables. The binding affinity and potency of CT-P10 remained unchanged, indicating that the efficacy of the antibody was maintained following in-use preparation.

CONCLUSIONS

We demonstrated that CT-P10 was stable after refrigerated storage for up to 6 weeks followed by incubation at room temperature.