Phase I Trial Of Sipuleucel-T Combined With Ipilimumab (Sipipi) In Progressive M-Crpc.

e16517Background: Sipuleucel–T (SIP-T) and ipilimumab (IPI) have potentially synergistic anticancer effects. Post treatment increases in disease-specific immunoglobulins (IG) correlate with improved survival. Methods: Nine men with progressive metastatic castrate-resistant prostate cancer M-CRPC received a fixed dose SIP-T followed by IPI. 3 pts had SIP-T in combination with IPI at each of 3 dose levels as follows: 1 mg/kg 1 week after SIP-T, 1 mg/kg 1 u0026 4 weeks after SIP-T or 1 mg/kg after 1, 4 u0026 7 weeks after SIP-T. IG specific for the GM-CSF/PAP fusion protein (PA2024) and to prostatic acid phosphatase (PAP) were measured prior to SIP-T, prior to IPI, 1 u0026 5 weeks following IPI, a subsequently every two months x 2 and every 3 months x 4. PAP and PA2024 IgG and IgG-IgM titers were compared across the three dosages and across time points. Results: Median age, Gleason score and previous hormonal interventions were 77 yrs., 8 and 3 respectively. Metastatic site: Bone (8); Lymph node only (1). Previous adjuv...