3PC-001 Storage of faricimab and high-dose aflibercept in polypropylene syringes does not impair antibody integrity after 28 days

<h3>Background and Importance</h3> For more than a decade, intravitreal injections of anti-vascular endothelial growth factor (anti-VEGF) drugs have been the mainstay treatment of neovascular age-related macular degeneration (nAMD). The IgG1 derived antibody faricimab and the recently approved high-dose formulation of the fusion protein aflibercept (114,3mg/mL) represent promising therapeutic approaches. However, in both cases, reliable stability data to enable compounding and storage in syringes are scarce. <h3>Aim and Objectives</h3> The aim of this study was to evaluate the long-term integrity of faricimab and aflibercept in polypropylene syringes. We analysed the compounded drug formulations for their chemical and physical stability, sterility, and binding affinity to their antigens after compounding for up to 28 days. The stability test was conducted based on the regulations of the GMP-guidelines, ICH Q5C and Ph.Eur. <h3>Material and Methods</h3> Both formulations were compounded under controlled clean room A conditions in a GMP-certified hospital pharmacy and stored under light protection and refrigeration (2°C to 8°C) for at least 28 days. Product characteristics were analysed using size-exclusion chromatography, nano differential scanning fluorimetry (thermal stability), UV-Vis (3D structure and aggregation index), dynamic light scattering (particle size distribution), pH measurement, sterility tests and endotoxin quantification. For quantification of binding affinity, we established a new method based on grating-coupled interferometry. In the case of faricimab, this method enabled the evaluation of the simultaneous binding mechanism of both VEGF and Ang-2 in solution, closely mimicking the mode of action after intravitreal injection. <h3>Results</h3> Both chemical and physical stability analyses revealed no impaired functionality of faricimab and aflibercept in polypropylene syringes after at least 28 days. Additionally, no significant alteration of the binding affinity to their antigens (VEGF and Ang-2 for faricimab; VEGF for aflibercept) was detected. The safety of the compounding process and the reliability of the primary packaging system were confirmed by product sterility and absence of bacterial endotoxins. <h3>Conclusion and Relevance</h3> The results of our stability study confirm that both faricimab and high-dose aflibercept are stable in ready-to-use polypropylene syringes for up to 28 days under refrigeration. This facilitates batch compounding and increases cost-effectiveness while maintaining patient safety. <h3>References and/or Acknowledgements</h3> <h3>Conflict of Interest</h3> No conflict of interest