Photostability of Ipilimumab and Nivolumab in the formulation and sterile saline or glucose solutions for parenteral administration

Photostability of Ipilimumab and Nivolumab in the formulation and sterile saline or glucose solutions for parenteral administration. Benedetta Fongaro, Valentina Cian, Giorgia Miolo and Patrizia Polverino de Laureto University of Padova, Department of Pharmaceutical and Pharmacological Sciences, Padova, Italy Background. Monoclonal antibodies are complex protein molecules, and their structural integrity influences their biological and pharmacological activity. Ipilimumab and Nivolumab, targeting the molecules CTLA-4, PD-1, respectively, have shown efficacy against several types of cancer and have demonstrated the superiority of the combination strategy compared to the single agent therapy.1 Aim. We investigated the impact of some stress factors, i.e., shaking, vibrations and light exposure, on two formulated monoclonal antibodies (mAbs) Ipilimumab and Nivolumab, to mimic their routine handling once released from the pharma industry, shipped to the hospital, diluted for the parenteral administration, and finally administered to the patients. Methods. Protein stability analyses, including aggregation and excipient effects on the protein structure, were carried out by spectroscopic methods (Uv-Vis, Fluorescence, and Circular dichroism), native and denaturing electrophoresis, and size exclusion chromatography analysis. Suntest CPS+ was used to simulate the conditions of one day or 3 weeks of sunlight exposure. Results. Among the selected critical stress factors to simulate the real-life handling of mAbs during transport, pneumatic systems, reconstitution, and administration to patients, only light exposure was able to affect the protein drug products. The two mAbs demonstrated a general instability to light as intact products and after dilution in saline and glucose solutions (both homemade and commercial sterile solution). The highest instability under light exposure was found in diluted glucose sterile solutions, suggesting the role of glucose degradation products on the photo-modification process of the two mAbs. Conclusion. Nivolumab and Ipilimumab are stable molecules under vigorous shaking and vibrations. However, they undergo structural change, mostly aggregation, upon exposure to artificial sunlight. The instability of mAbs upon light exposure could have a potential impact on the safety and efficacy of these very active drugs in anticancer therapy. 1) Marchetti P. Botticelli A., Agnostic evaluation of ipilimumab and nivolumab association: a metanalysis. J Transl Med, 2020. 2) Le Basle Y., Chennel P., Physicochemical Stability of Monoclonal Antibodies: A Review. Journal of Pharmaceutical Sciences, 2020. Book