A Study Evaluating Whether Pembrolizumab Alone or in Combination With CMP-001 Improves Efficacy of Treatment in Patients With Operable Melanoma

Inclusion Criteria: * Patient must be \>= 18 years of age * Patient must have an Eastern Cooperative Oncology Group (ECOG) performance status of 0 or 1 * Patient must have a histologic diagnosis of melanoma belonging to the following American Joint Committee on Cancer (AJCC) 8th edition TNM stages: * T0, Tx or T1-4; and * N1b, N2b, N2c, N3b or N3c * Patients may have a presentation with primary melanoma with concurrent regional nodal and/or in-transit metastasis; or patients may have a history of primary melanoma or unknown primary melanoma presenting with clinically detected regional nodal and/or in-transit recurrence; and may belong to any of the following groups: * Primary cutaneous melanoma with clinically apparent regional lymph node metastases and/or in-transit metastases * Clinically detected recurrent melanoma at the proximal regional lymph node(s) basin * Primary cutaneous melanoma with concurrent nodal disease involving a single (or multiple) regional nodal group(s) if considered potentially surgically resectable at baseline * Clinically detected nodal melanoma (if single site) arising from an unknown primary * In-transit cutaneous metastases with or without regional lymph node involvement permitted if considered potentially surgically resectable at baseline * NOTE: Patients with mucosal and/or uveal melanoma are not eligible for the study * Patient must be a candidate for definitive surgery and have met with the treating surgical oncologist pr…