Ipilimumab with or without Talimogene Laherparepvec in Unresected Melanoma

- Histologically confirmed diagnosis of malignant melanoma. - Stage IIIB, IIIC, IVM1a, IVM1b, or IVM1c disease that is not suitable for surgical resection - Phase1: Treatment naïve: Must not have received any prior systemic anticancer treatment consisting of chemotherapy, immunotherapy, or targeted therapy for unresected stage IIIB to IV melanoma. - Phase 2: -- Either treatment naïve or received only one line of systemic anticancer therapy if v-raf murine sarcoma viral oncogene homolog B1 (BRAF) wild-type or up to two lines of systemic anticancer therapy including one BRAF inhibitor-containing regimen if BRAF mutant. Treatments given in an adjuvant setting (eg, interferon, radiotherapy, isolated limb perfusion, or investigational agents) are not considered as prior lines of therapy. No prior talimogene laherparepvec, other oncolytic virus therapies, or tumor vaccines are allowed, even if given in the adjuvant setting. -- Subjects treated with prior ipilimumab must have had partial response (PR), complete response (CR), or at least 6 months of stable disease followed by disease progression. -- Subjects previously treated with anti-program death-1 (PD1) or anti-cytotoxic T-lymphocyte associated antigen 4 (CTLA-4) antibodies must not have discontinued therapy due to any treatment-related adverse events including immune-related adverse events. Prior treatment-related adverse events should also be fully resolved and not requiring treatment for at least 28 days prior to randomization. - Measurable disease defined as one or both of the following -- at least 1 melanoma lesion that can be accurately and serially measured in at least 2 dimensions and for which the longest diameter is ≥ 10 mm and with perpendicular diameter ≥ 5 mm as measured by contrast-enhanced or spiral computed tomography (CT) scan for visceral or nodal/soft tissue disease. Lymph nodes must measure > 15 mm in their short axis to be considered measurable by CT scan. -- at least 1 superficial cutaneous or subcutaneous melanoma lesion that can be accurately and serially measured in at least 2 dimensions and for which the short axis is ≥ 5 mm as measured by calipers - Injectable disease (ie, suitable for direct injection or through the use of ultrasound [US] guidance) defined as follows: -- at least 1 injectable cutaneous, subcutaneous, or nodal melanoma lesion ≥ 5 mm in longest diameter - Eastern Cooperative Oncology Group (ECOG) performance status 0 or 1 - Adequate hematologic, hepatic, renal, and coagulation functions

- Primary uveal or mucosal melanoma - History or evidence of melanoma associated with immunodeficiency states (eg, hereditary immune deficiency, organ transplant, or leukemia) - Phase 1b: History or evidence of central nervous system (CNS) metastases - Phase 2: Clinically active cerebral melanoma metastases. Subjects with up to 3 cerebral metastases, and neurological performance status of 0 may be enrolled, provided that all lesions have been adequately treated with stereotactic radiation therapy, craniotomy, or Gamma knife therapy, with no evidence of progression, and have not required steroids, for at least 2 months prior to enrollment. - History or evidence of symptomatic autoimmune disease (such as pneumonitis, glomerulonephritis, vasculitis, rheumatoid arthritis, inflammatory bowel disease, systemic lupus erythematosus, scleroderma, or other), or history of autoimmune disease that required systemic treatment (ie, use of corticosteroids, immunosuppressive drugs or biological agents used for treatment of autoimmune diseases) in past 2 months prior to enrollment. Replacement therapy (eg, thyroxine for hypothyroidism, insulin for diabetes mellitus) is not considered a form of systemic treatment for autoimmune disease. - History of or plan for splenectomy or splenic irradiation - Active herpetic skin lesions or prior complications of herpes simplex type-1 virus (HSV-1) infection (eg, herpetic keratitis or encephalitis). - Requires intermittent or chronic systemic (intravenous or oral) treatment with an antiherpetic drug (eg, acyclovir), other than intermittent topical use - Known human immunodeficiency virus (HIV) disease - Known acute or chronic hepatitis B or hepatitis C infection - Phase 1b: Prior talimogene laherparepvec, ipilimumab, other CTLA-4 inhibitors, PD-1 inhibitors, or tumor vaccine - Phase 2: Prior talimogene laherparepvec, other oncolytic virus therapies, or tumor vaccines - Currently receiving or less than 28 days since ending systemic anticancer treatment for unresected stage IIIB to IV melanoma