Development of a robust reporter-based assay for the bioactivity determination of anti-VEGF therapeutic antibodies

Area of Science:

• Biotechnology
• Pharmacology
• Oncology

Background:

• Anti-VEGF biologic agents are crucial in cancer therapy, with bevacizumab (BVZ) being a prominent example.
• Accurate bioactivity determination is essential for the safety and efficacy of therapeutic antibodies like BVZ.
• Current lot release and stability testing for BVZ relies on tedious anti-proliferation assays with high variability.

Purpose of the Study:

• To develop and validate a novel reporter gene assay (RGA) for potency determination of bevacizumab (BVZ).
• To establish a more precise, sensitive, and simpler assay compared to existing methods.
• To assess the applicability of the RGA for other VEGF-targeted biotherapeutics.

Main Methods:

• Development of an HEK293 cell line stably expressing vascular endothelial growth factor receptor 2 (VEGFR-2).
• Integration of a luciferase reporter gene controlled by nuclear factor activated T cell (NFAT) response elements.
• Utilized the VEGF-VEGFR-NFAT pathway for bioactivity assessment.

Main Results:

• The developed RGA demonstrated superior precision, sensitivity, and simplicity compared to the human umbilical vein endothelial cell (HUVEC) proliferation assay.
• The RGA is applicable to other VEGF-targeted biotherapeutics beyond bevacizumab.
• Preliminary validation indicates the RGA's potential as a reliable tool for potency determination.

Conclusions:

• The novel reporter gene assay based on the VEGF-VEGFR-NFAT pathway is a viable supplement to traditional HUVEC assays.
• This RGA can be employed for the potency determination of bevacizumab (BVZ) and other anti-VEGF antibody-based biotherapeutics.
• The findings pave the way for improved quality control in the manufacturing of anti-angiogenic cancer therapies.