Nivolumab With or Without Ipilimumab in Advanced Metastatic Cancer

Single-agent nivolumab will be administered at 360 mg IV Q3W. Participants who continue to show clinical benefit after the first disease assessment will receive nivolumab 480 mg IV Q4W until PD or intolerable toxicity.

For nivolumab and ipilimumab combination therapy, nivolumab will be administered at 360 mg IV Q3W, and ipilimumab will be administered at 1 mg/kg IV Q3W for the first 2 doses and then Q6W for the 3rd and 4th doses, followed by single-agent nivolumab 480 mg IV Q4W until PD or intolerable toxicity.

For nivolumab and ipilimumab combination therapy, CD8 low arm, approximately 10 participants will be randomly allocated into 1 of 2 cohorts, using different doses of ipilimumab administered in 6-week cycles. Participants assigned to Prostate Cohort A will receive nivolumab 1 mg/kg Q3W and ipilimumab 3 mg/kg every 6 weeks (Q6W) for 2 cycles, then nivolumab maintenance 480 mg Q4W until PD or intolerable toxicity. If the safety profile of Prostate Cohort B is deemed unacceptable, an additional 10 participants will be enrolled in Prostate Cohort A.

For nivolumab and ipilimumab combination therapy, CD8 low arm, approximately 10 participants will be randomly allocated into 1 of 2 cohorts, using different doses of ipilimumab administered in 6-week cycles. Participants assigned to Prostate Cohort B will receive nivolumab 1 mg/kg Q3W and ipilimumab 5 mg/kg Q6W for 2 cycles, then nivolumab maintenance 480 mg Q4W until PD or intolerable toxicity. If Prostate Cohort B is determined to have a tolerable safety profile, an additional 10 participants will be enrolled to receive nivolumab 1 mg/kg Q3W and ipilimumab 5 mg/kg Q6W for 2 cycles, then nivolumab maintenance 480 mg Q4W until PD or intolerable toxicity.