PD25-06 CHARACTERIZATION OF LONG-TERM SURVIVORS FROM PROCEED, A REGISTRY OF SIPULEUCEL-T IN METASTATIC CASTRATION-RESISTANT PROSTATE CANCER (MCRPC)

INTRODUCTION AND OBJECTIVES:PROCEED [NCT01306890], a large real-world study of sipuleucel-T in men with mCRPC, offers an opportunity to examine patients who experienced longer term (≥3 yr) survivals after receiving sipuleucel-T. The current analysis seeks insights regarding these patients, especially noting the timing of sipuleucel-T relative to the other FDA-approved treatments in the modern era.METHODS:Men with mCRPC receiving sipuleucel-T, given every 2 weeks x 3, were eligible for PROCEED. Follow-up continued until death, study withdrawal, or a minimum of 3 years. Long-term survivors were defined as those who survived ≥3 yr. Baseline characteristics and treatments received pre/post-sipuleucel-T are reported in this ad-hoc subgroup analysis.RESULTS:From 2011-2014, 1902 men received ≥1 sipuleucel-T infusion. Of these, an estimated 42.3% survived ≥3yr. At baseline, long-term survivors (OS ≥3 yr) and those who survived <3 yr had no notable differences in laboratory measures or patterns of metastatic sprea...