Phase 3 Clinical Study

PROSPECT is a global, randomized, double-blind, placebo-controlled phase 3 study being conducted under a Special Protocol Assessment (SPA) from the FDA. The objective of the study is to determine whether PROSTVAC® alone or in combination with GM-CSF is effective in prolonging overall survival in men with few or no symptoms from metastatic, castration-resistant prostate cancer (mCRPC). 

By January 2015, the study had been fully enrolled with 1,298 asymptomatic or minimally symptomatic mCRPC patients. Patients were enrolled at more than 200 sites in 15 countries, including Australia, Belgium, Canada, Denmark, Estonia, France, Germany, Iceland, Israel, Netherlands, Poland, Russia, Spain, United Kingdom and the United States.

Design of the PROSPECT Clinical Study

Men with non/minimally symptomatic mCRPC (n=1200)  PROSTVAC  Long-term follow up  SURVIVAL 

5 Months Treatment

Interim analysis plan

The PROSPECT study statistical analysis plan, accepted by the FDA under the SPA, includes prespecified interim analyses of data to evaluate whether the study should continue as planned or potentially be stopped early, either for efficacy or futility. If the study exceeds the efficacy threshold during an interim analysis, applications for product marketing approval may be filed with regulatory authorities at an earlier stage, potentially shortening the overall development time.

Additional details of the study can be found on