Table 3.

Studies of Ipilimumab in mCRPC and PSA response rates (OS, Overall survival; PFS, Progression-free survival; PSA, Prostate specific antigen).

Study/Intervention	Patients	Outcomes
Phase I: Ipilimumab + Poxviral vaccine Escalating Ipi: 1, 3, 5, 10 mg/kg; 6 or more doses Recombinant fowlpox PSA-Tricom: monthly boosts (18)	Asymptomatic 6 post docetaxel 24 docetaxel naïve	Post docetaxel: 1 (17%) of 6 had a PSA response; median PFS = 2.4 mos (1.5–3.7) Chemotherapy naïve: 14 (58%) of 24 had PSA response; 6 (25%) of 24 had PSA declines >50%; median PFS 5.9 (3.4–8.8)
Phase I/II: Dose escalation study with Ipilimumab +/– radiation (8Gy/lesion) (19)	Asymptomatic, +/– prior treatments	In the 10 mg/kg ipilimumab +/– radiation cohort (n = 50), 8 had confirmed PSA decline (6 prior chemo, 2 chemo naïve)
Phase I: Dose escalation study with Ipilimumab (up to 10 mg/kg) + Sargramostim (20)	42 patients, chemotherapy naïve	5 patients experienced > 50% decline in PSA (2 of them in 10 mg/kg ipilimumab cohort)
Phase II: Single-Arm Ipilimumab (3 mg/kg IV every 3 weeks, up to 4 doses) (21)	30 patients with mCRPC	Median PSA PFS: 1.7 mo; median radiographic PFS: 3.0 mo; median OS 24.3 mo
Phase III: Ipilimumab (10 mg/kg) vs. placebo (12)	602 patients, chemotherapy-naïve, asymptomatic (or minimally symptomatic)	Median PFS: 5.6 mo in ipilimumab cohort vs. 3.8 mo in placebo OS: No statistically significant difference between two cohorts
Phase III: Ipilimumab (10 mg/kg) vs. placebo (11)	799 patients, all had prior radiation treatment	Median PFS: 4.0 mo in ipilimumab cohort vs. 3.1 in placebo OS: No statistically significant difference between two cohorts