As proposed in our proposal, we have examined two agents in ex vivo and in vitro models (Bevacizumab and Pegaptinib), and only Bevacizumab in human study. We recruited patients diagnosed with advanced colorectal cancer, and isolated the platelets at different interval.
We observed a dismal effect of bevacizumab on the concentrations of intra-platelet VEGF-A. The human study results correspond with our ex vivo and in vitro experiments. Compared to serum and plasma, the intra-platelet VEGF-A concentrations remained nearly unchanged. We have also monitored the kinetics of different isoforms of VEGF-A in platelets obtained from the patients before and after Bevacizumab administration. To increase the number in human study, we have recently modified the protocol of patient recruitment.