A Study of Pembrolizumab (+) Berahyaluronidase Alfa (MK-3475A) (Pembrolizumab Formulated With Berahyaluronidase Alfa (MK-5180)) in Japanese Participants With Recurrent or Metastatic Cutaneous Squamous Cell Carcinoma (R/M cSCC) or Locally Advanced (LA) Unresectable cSCC (MK-3475A-E39)

The key inclusion and exclusion criteria include but are not limited to the following: Inclusion Criteria: * Has histologically confirmed cSCC by the investigator as the primary site of malignancy * R/M cSCC cohort only: Has metastatic disease, defined as disseminated disease distant to the initial/primary site of diagnosis, and/or has locally recurrent disease that has been previously treated (with either surgery or radiotherapy) and is not curable by either surgery or radiotherapy * LA unresectable cSCC cohort only: Is ineligible for surgical resection * LA unresectable cSCC cohort only: Has received prior radiation therapy (RT) to index site or has been deemed to be not eligible for RT * LA unresectable cSCC cohort only: Has received prior systemic therapy for curative intent are eligible regardless of regimen * Has a life expectancy of greater than 3 months * Must provide archival tumor tissue sample or newly obtained core or excisional biopsy of a tumor lesion not previously irradiated Exclusion Criteria: * Has cSCC that can be cured with surgical resection, radiotherapy, or with a combination of surgery and radiotherapy. * Has any other histologic type of skin cancer other than invasive squamous cell carcinoma as the primary disease under study * Has received prior systemic anticancer therapy including investigation agents within 4 weeks before allocation * Has not adequately recovered from major surgery or has ongoing surgical complications * Received prior radiotherapy within 2 weeks of study intervention, or had radiation-related toxicities, requiring corticosteroids * Received a live or live-attenuated vaccine within 30 days before the first dose of study intervention * Known additional malignancy that is progressing or has required active treatment within the past 2 years * Has an ongoing active infection requiring systemic therapy * Has a history of human immunodeficiency virus (HIV) infection * Has an active autoimmune disease that has required systemic treatment in past 2 years * Has history of allogenic tissue/organ transplant