A Clinical Study of V940 and Pembrolizumab (MK-3475) in People With Melanoma (V940-012/INTerpath-012)

Inclusion Criteria:

The main inclusion criteria include but are not limited to the following:

• Has unresectable and histologically confirmed Stage III or IV cutaneous melanoma perAmerican Joint Committee on Cancer (AJCC) Eighth Edition guidelines.

• Has been untreated for melanoma except if participant received prior adjuvant orneoadjuvant therapy with targeted therapy or immunotherapy (such as anti-cytotoxicT-lymphocyte-associated protein [CTLA-4], anti-programmed cell death 1 protein [PD-1] therapy or interferon), and only if relapse did not occur within 12 monthsafter treatment discontinuation.

• Have documentation of serine/threonine-protein kinase B-raf (BRAF) V600-activatingmutation status or had BRAF V600 mutation testing per local institutional standardsduring the screening period (participants with BRAF mutation positive melanoma aswell as BRAF wild-type or unknown are eligible).

• Have the presence of at least 1 measurable lesion by computed tomography (CT) ormagnetic resonance imaging (MRI) per Response Criteria in Solid Tumors Version 1.1 (RECIST 1.1) as determined by the local site investigator/radiology assessment.

• Provides tumor tissue (preferably from a metastatic site and, if not available, fromthe primary tumor) that is suitable for next generation sequencing and biomarkeranalysis as required for this study.

• Participants with human immunodeficiency virus (HIV) must have well controlled HIVon antiretroviral therapy (ART).

• Participants who are hepatitis B surface antigen (HBsAg) positive are eligible ifthey have received hepatitis B virus (HBV) antiviral therapy for at least 4 weeks,and have undetectable HBV viral load prior to randomization.

• Participants with history of hepatitis C virus (HCV) infection are eligible if HCVviral load is undetectable at screening.

Exclusion Criteria:

The main exclusion criteria include but are not limited to the following:

• Has clinically significant heart failure, defined as New York Heart Associationclass III or IV, within the past 6 months, unless the disease is well controlled inthe opinion of the investigator.

• HIV-infected participants with a history of Kaposi's sarcoma and/or MulticentricCastleman's Disease.

• Has ocular or mucosal melanoma.

• Received transfusion of blood products (including platelets or red blood cells) oradministration of colony-stimulating factors (including granulocytecolony-stimulating factor, granulocyte macrophage colony-stimulating factor, orrecombinant erythropoietin) within 2 weeks of the Screening blood sample (includingthe blood sample for V940 generation).

• Received prior therapy with an anti-PD-1, anti-PD-L1, or anti-PD-L2 agent, or withan agent directed to another stimulatory or coinhibitory T-cell receptor (eg,CTLA-4, lymphocyte activation gene 3 [LAG-3], tumor necrosis factor receptors [OX-40or CD137]), with some exceptions.

• Received prior systemic anticancer therapy for melanoma before randomization, withsome exceptions.

• Received prior radiotherapy within 2 weeks of start of study intervention or hasongoing radiation related toxicities.

• Received a live or live-attenuated vaccine within 30 days before the first dose ofstudy intervention.

• Received prior treatment with another universal or personalized cancer vaccine.