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 ofmalignancy

• R/M cSCC cohort only: Has metastatic disease, defined as disseminated diseasedistant to the initial/primary site of diagnosis, and/or has locally recurrentdisease that has been previously treated (with either surgery or radiotherapy) andis 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 indexsite or has been deemed to be not eligible for RT

• LA unresectable cSCC cohort only: Has received prior systemic therapy for curativeintent 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 excisionalbiopsy of a tumor lesion not previously irradiated

Exclusion Criteria:

• Has cSCC that can be cured with surgical resection, radiotherapy, or with acombination of surgery and radiotherapy.

• Has any other histologic type of skin cancer other than invasive squamous cellcarcinoma 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 surgicalcomplications

• Received prior radiotherapy within 2 weeks of study intervention, or hadradiation-related toxicities, requiring corticosteroids

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

• Known additional malignancy that is progressing or has required active treatmentwithin 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 2years

• Has history of allogenic tissue/organ transplant