Additional Study Information: The purpose of this study is to find out more about talimogene laherparepvec (formerly known as OncoVEXGM-CSF), in people with advanced melanoma when given in combination with another drug called ipilimumab. Melanoma is a type of skin cancer. Advanced melanoma means the tumor is not removable by surgery or has spread to other parts of the body. Phase 1 of the study will be done to see if talimogene laherparepvec in combination with ipilimumab is safe for people with advanced melanoma to take. Phase 2 of this study will be done to see if talimogene laherparepvec in combination with ipilimumab improves survival and, whether the combination causes any increase in the frequency of side effects. Participants will be in this study for about 42 months which include a screening period, a treatment period, an off treatment visit and a follow-up period.