Study Evaluating Cemiplimab Alone and Combined With RP1 in Treating Advanced Squamous Skin Cancer

Key Inclusion Criteria:

   - Histologically confirmed locally advanced or metastatic cutaneous squamous cell
   carcinoma

   - Patients with locally advanced disease who are not suitable candidates for surgical or
   radiological treatment of lesions or have refused those treatments

   - At least 1 lesion that is measurable and injectable by study criteria

   - Eastern Cooperative Oncology Group (ECOG) performance status ≤1. Patients with ECOG PS
   2 at baseline may be allowed to enroll if PS 2 status is only related to the CSCC
   disease under study

   - Anticipated life expectancy >12 weeks

   - All patients must consent to provide archived or newly obtained tumor material for
   central pathology review for confirmation of diagnosis of CSCC.

Key Exclusion Criteria:

   - Prior treatment with an oncolytic therapy

   - Patients with active significant herpetic infections or prior complications of HSV-1
   infection (e.g. herpetic keratitis or encephalitis)

   - Patients who require intermittent or chronic use of systemic (oral or intravenous)
   anti-virals with known anti-herpetic activity (e.g. acyclovir)

   - Ongoing or recent (within 5 years) evidence of significant autoimmune disease that
   required treatment with systemic immunosuppressive treatments

   - Prior treatment with an agent that blocks the PD-1/PD-L1 pathway.

   - Prior treatment with other immune modulating agents other than as adjuvant or
   neoadjuvant therapy within 3 years.

   - Untreated brain metastasis(es) that may be considered active.

   - Acute or chronic active hepatitis B or known history of hepatitis B or hepatitis C or
   human immunodeficiency virus (HIV) infection

   - History of ILD/pneumonitis within the last 5 years or a history of ILD/pneumonitis
   requiring treatment with systemic steroids.

   - Any major or surgical procedure ≤ 28 days before randomization

   - Administration of live vaccines ≤ 28 days before randomization

Note: Other protocol defined Inclusion/Exclusion criteria apply.