BERKELEY, CA (UroToday.com) - Although results with antiangiogenics did not show positive overall survival, a rationale still exists for the study of the angiogenic pathway.
This is proposed by the following trials: A phase III study ongoing with VEGF-trap (aflibercept) with or without docetaxel-prednisone in first-line ( www.clinicaltrials.gov NCT00519285), and the phase III trial evaluating the efficacy and safety of docetaxel and prednisone with or without lenalidomide www.clinicaltrials.gov NCT00988208).
Moreover, we do not yet know which is the best endpoint or biomarker to evaluate the efficacy of these new agents. In fact, PSA serum levels may not be a valid surrogate endpoint for definitive survival in advanced prostate cancer patients. New serum biomarkers of osteoclast activity and urine markers together with quality of life assessments, circulating endothelial cells and reduction in analgesic intake need should be added to the classic radiological and PSA measurements.
The search for new biomarkers that may be able to predict a better clinical outcome of patients receiving sunitinib is clearly needed because of the moderate activity together with the adjusted safety profile. It is very likely that the future success, not only for sunitinib but for the other new antiangiogenics in development, will be driven by the discovery of accurate and selective biomarkers.
Activity with sunitinib has been seen in a very highly treated population of patients with taxane-refractory CRPC. An overall clinical benefit based on PSA was observed in more than 50% of patients. Subrogate biomarkers are greatly needed to assess the real efficacy of new targeted agents in CRPC patients, and the final confirmation of activity will come from ongoing randomized studies.
Daniel Castellano, MD as part of Beyond the Abstract on UroToday.com. This initiative offers a method of publishing for the professional urology community. Authors are given an opportunity to expand on the circumstances, limitations etc... of their research by referencing the published abstract.