This is an open-label, Phase 1, multicenter study to evaluate the safety, PK, and PD of an anti-CTLA-4 human monoclonal antibody (AGEN1884) and to estimate the MTD in subjects with advanced or refractory cancer. The study will consist of a 3+3 dose escalation cohort starting at a near minimally anticipated biologic effect level (MABEL) dose with expansion cohorts at 1 mg/kg and 3 mg/kg..