Article Text
PDF
Abstract
Background and importance Ziv-aflibercept (Zaltrap) is an Fc-fusion protein used in the treatment of colorectal cancer. Changes in the structure or aggregation, which may arise from handling and storage, may affect the efficacy of the treatment and it could cause severe immune reactions in patients. The shelf life indicated by the manufacturer for the unopened vial is 3 years; there is no information on the surplus of opened vials.
Aim and objectives To compare the biophysical stability of ziv-aflibercept (Zaltrap) stored refrigerated at 4°C and at room temperature protected from light for 2 weeks.
Material and methods Three independent samples of fresh ziv-aflibercept were collected from hospital and stored in amber glass vials protected from light at 4°C and at room temperature.
Particulate: dynamic light scattering (DLS) readings were carried out in a protein solution DynaPro-99 system dynamic light scattering module equipped with a temperature control micro sampler (Wyatt, Santa Bárbara, California, USA) for obtaining the hydrodynamic radius and polydispersity.
Tertiary structure: intrinsic tryptophan fluorescence measurements were carried out on a Cary eclipse spectrofluorometer (Agilent, Santa Clara, California, USA). Each spectrum was reduced to a single a dimensional number (centroid):
LMW aggregates: size exclusion chromatography (SEC) was used. The analysis was performed by liquid chromatography using an Agilent 1100 chromatograph equipped with a quaternary pump, degasser, autosampler, column oven and photodiode array detector (Agilent).
Results No significant changes were detected in the samples stored refrigerated by any of the techniques used: aggregation did not occur, supported by the results from DLS and SEC. No changes in conformation were detected: fluorescence centroid was maintained.
Significant changes were detected in the samples stored at room temperature: the start of aggregation was detected by SEC but larger aggregates were not detected by DLS. Centroid value increased significantly, indicating conformational modifications.
Conclusion and relevance Ziv-Aflibercept (Zaltrap) remained stable for 14 days regarding visual appearance, LMW aggregates, particulate and conformation when stored at 4°C. However, storage at room temperature promoted ziv-aflibercept modifications. This result encourages more studies with samples stored at 4°C to establish the stability of opened vials of Zaltrap.
References and/or acknowledgements Project FIS- PI-17/00547 (Institute Carlos III, Spain), which means that it was also partially supported by European Regional Development Funds.
No conflict of interest.