Development of the Drug Product Formulation of the Bevacizumab Biosimilar PF-06439535 (Bevacizumab-bvzr).

Background: PF-06439535 (bevacizumab-bvzr; Zirabev^®) is a biosimilar of bevacizumab reference product (RP; Avastin^®). This study describes the formulation development for PF-06439535.

Methods: PF-06439535 was formulated in several buffers and stored for 12 weeks at 40 °C to determine the optimal buffer and pH under stressed conditions. Subsequently, PF-06439535 at 100 and 25 mg/mL was formulated in a succinate buffer with sucrose, edetate disodium dihydrate (EDTA), and polysorbate 80, and in the RP formulation. Samples were stored at - 40 °C to 40 °C for ≤ 22 weeks. The physicochemical and biological properties relevant to the safety, efficacy, quality, or manufacturability were investigated.

Results: When stored at 40 °C for 13 days, PF-06439535 demonstrated optimal stability in histidine or succinate buffers and was more stable in the succinate formulation than the RP formulation, under both real-time and accelerated stability conditions. There were no significant changes in the quality attributes of 100 mg/mL PF-06439535 after storage at - 20 °C and - 40 °C for 22 weeks, and there were no changes in the quality attributes of 25 mg/mL PF-06439535 after storage at 5 °C (recommended storage temperature). Changes were observed at 25 °C for 22 weeks or at 40 °C for 8 weeks as expected. No new degraded species were observed in the biosimilar succinate formulation compared with the RP formulation.

Conclusions: Results demonstrated that 20 mM succinate buffer (pH 5.5) is the PF-06439535 preferred formulation, and that sucrose is an effective cryoprotectant for processing and frozen storage, and an effective stabilizing excipient for 5 °C liquid storage of PF-06439535.