Bevacizumab's effect on recurrent glioblastoma and ovarian cancer is transient, and most patients' tumors eventually progress. Understanding the action mechanism of Bevacizumab is crucial to developing strategies for optimizing treatment. This can be done utilizing primary human umbilical vein cells expressing VEGF.
However, this type of assay presents a long time to perform, has a high degree of variation, and has difficulty in validation.
This study aimed to shed light on the bevacizumab neutralizing activity and antibody-dependent cellular cytotoxicity activity (ADCC). The approach to achieve this was to determine bevacizumab activity in 52 patients' samples (46 ovarian cancer and six glioblastomas utilizing the highly sensitive VEGF responsive iLite cells to determine neutralizing activity and the iLite ADCC effector cells expressing CD16a for ADCC analysis. The VEGF-responsive iLite cells are sensitive, precise, and accurate in determining bevacizumab activity and that Bevacizumab neutralizes soluble VEGFA and membrane-bound VEGFA1.
The nonparametric Spearman correlation analysis of 52 pooled samples identified an existing correlation between the bevacizumab’s neutralizing and the ADCC activities. Furthermore, the neutralizing activity and the ADCC activity correlated with circulating levels of bevacizumab.
Together with previous evidence this study shows that the iLite cells enable quantifying the direct VEGF-neutralizing activity of bevacizumab in samples from patients. Furthermore, it suggests similarities in the action of anti-tumor activity of bevacizumab in two different solid tumors.
Lallemand, C., Fernando-Miguel, et al. Analysis of Bevacizumab Activity Following Treatment Patients with Ovarian Cancer or Glioblastoma. Medical Research Archives (2023). DOI: 10.18103/mra.v11i3.3652