Physicochemical stability of durvalumab (Imfinzi^®) concentrate for solution in original vials after first opening

Abstract Objectives Durvalumab (Imfinzi ® ), a PD-L1 monoclonal antibody (mAb) medication is available as concentrate (50 mg/mL) for solution infusion. The summary of product characteristics provides information about the physicochemical stability ready-to-administer durvalumab preparations (vehicle 0.9 % NaCl, G5%), but not after first opening. objective this study was to determine opening over period 28 days. Methods Imfinzi vials were punctured and stored refrigerated (2–8 °C) or at room temperature (20–25 light protected. At predefined time points (day 0, 7, 14, 21, 28) concentrated determined by ion-exchange/size-exclusion high-performance liquid chromatography (IE-/SE-HPLC) with photodiode array detection pH measurement. Vials inspected regard changes color, clarity, visible particles any point. Results Regardless storage temperature, 50 mg/mL solutions remained physiochemically stable days in vials. concentrations monomer unchanged no secondary peaks (fragments, aggregates) observed SE-HPLC chromatograms. IE-HPLC test results showed substantial peak areas main acidic basic charge variants during whole period. Appearance until end study. Conclusions conditions none analytical methods indicated instability intact To avoid microbiological under refrigeration recommended.