Talimogene Laherparepvec and Pembrolizumab in Treating Patients With Stage III-IV Melanoma

PRIMARY OBJECTIVE: I. To evaluate the objective response rate (confirmed complete and partial responses) of treatment with talimogene laherparepvec (T-VEC) in combination with pembrolizumab (MK-3475) following progression on prior anti-PD-1 or anti-PD-L1 therapy alone or in combination with other agents different from talimogene laherparepvec (T-VEC). SECONDARY OBJECTIVES: I. To estimate the durable response rate. II. To estimate the objective response rate (ORR) defined as confirmed and unconfirmed, complete and partial responses in the injected lesions. III. To estimate the ORR in the non-visceral, non-injected lesions. IV. To estimate the ORR in the visceral lesions (Cohort A). V. To estimate the median progression-free survival (PFS). VI. To estimate the median overall survival (OS). VII. To evaluate the toxicity of the regimen. TRANSLATIONAL OBJECTIVES: I. To evaluate whether adding talimogene laherparepvec (T-VEC) to PD1 blockade can increase T-cell infiltration into tumors and whether change in T-cell infiltration is associated with response. II. To evaluate whether adding talimogene laherparepvec (T-VEC) to PD1 blockade can increase T-cell receptor (TCR) clonality in tumors and in peripheral blood and whether increased TCR clonality is associated with response. III. To evaluate whether intra-tumoral injection of talimogene laherparepvec (T-VEC) can improve the tumor immune microenvironment. IV. To evaluate whether tumor mutational load, mutations in the IFN pathway, and circulating tumor deoxyribonucleic acid (DNA) profile are is associated with response to talimogene laherparepvec (T-VEC) plus pembrolizumab (MK-3475) therapy in the anti-PD1/L1 therapy refractory melanoma patients. OUTLINE: Patients receive talimogene laherparepvec intralesionally (IL) and pembrolizumab intravenously (IV) over 30 minutes on day 1. Treatment repeats every 21 days for up to 36 cycles in the absence of disease progression or unacceptable toxicity. After completion of study treatment, patients are followed up every 6 months for up to 1 year and then annually for a total of 5 years.