Six-month stability of bevacizumab (Avastin) binding to vascular endothelial growth factor after withdrawal into a syringe and refrigeration or freezing.

Abstract

To determine the change in anti-vascular endothelial growth factor (VEGF) activity of bevacizumab (Avastin, Genentech, Inc., San Francisco, CA) after refrigeration or freezing. Samples of bevacizumab were drawn up from new vials into plastic tuberculin syringes and refrigerated at 4 degrees C for 1 week, 3 weeks, 1 month, 3 months, and 6 months. The vials and syringes were stored at 4 degrees C, and the syringes were capped with a needle. One syringe was frozen at -10 degrees C. The bevacizumab concentration was measured, via its binding to VEGF-165. The percentage of degradation of bevacizumab in the previously pierced vials stored at 4 degrees C compared with that in the unpierced vial was 9.6% at 3 months and 12.7% at 6 months. The bevacizumab drawn into the syringe and stored at 4 degrees C was degraded by 1.6% at 1 week, 0% at 3 weeks, 8.8% at 3 months, and 15.9% at 6 months. The bevacizumab frozen in a syringe at -10 degrees C was degraded by 12.0% at 6 months. The anti-VEGF activity of bevacizumab may degrade minimally over time, with storage.