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