Biosimilar Infliximab, Zessly, Maintains Safety and Efficacy Under Extended In-Use Conditions

European-approved biosimilar infliximab, Zessly (also approved in the United States as Ixifi), has undergone extensive stability and in-use testing to ensure that its quality is robust, but regulatory requirements do not stipulate extended in-use handling. A study recently published in Drugs in R&D sought to provide healthcare providers with information on the stability of the biosimilar in extended in-use conditions after dilution and reformulation for intravenous administration.

In the study, 55 vials of the biosimilar were produced under aseptic conditions, and reconstitution and dilution were performed in line with good manufacturing practice in a laboratory. In total, 33 of the vials were reconstituted for storage at 5°C (± 3°C) for up to 30 days or 25°C  (± 2°C) at a relative humidity of 60% (± 5%) for up to 14 days, which were considered worst-case handling conditions.

An additional 22 vials were reconstituted for dilution. Vials of the antibody were diluted in 250 mg polyethylene bags to obtain 2 concentrations: 0.4 mg/mL and 4.0 mg/mL. One bag of each concentration was stored for up to 30 the same temperatures and relative humidity as described above.

When sampled, osmolality, pH, and clarity all met predefined acceptance criteria, with no changes observed at dilution or storage. There were no changes in subvisible particle content across batches, solutions, storage conditions, or storage durations. No notable changes in protein concentration were observed over time across batches or storage conditions.

Absence of changes in ultraviolet absorption indicated minimal protein aggregation, precipitation, and adsorption under in-use conditions, and all results met predefined criteria.

No significant difference in charge variants were identified. There were also no changes in high-molecular-weight variants. The abundance of fragments was low, and the purity was high across batches and storage conditions.

Analysis of bioassay data for the samples showed no changes in potency, and all results were within assay variability limits and met predefined criteria.

The authors concluded that the physiochemical and biological analyses demonstrated that the biosimilar is not affected by reconstitution, dilution, and extended storage in infusion bags. These findings, they write, provide added reassurance to healthcare providers that the biosimilar is safe and effective under extended in-use conditions.

Reference

Vimpolsek M, Gottar-Guillier M, Rossy E. Assessing the extended in-use stability of the infliximab biosimilar PF-06438179/GP1111 following preparation for intravenous infusion [published February 27, 2019]. Drugs R D. doi: 10.1007/s40268-019-0264-1.