Study of REGN2810 in Patients With Advanced Cutaneous Squamous Cell Carcinoma

Key Inclusion Criteria:

- At least 1 measurable lesion

- Eastern Cooperative Oncology Group (ECOG) performance status ≤1

- Adequate bone marrow function

- Adequate renal function

- Adequate hepatic function

- Archived or newly obtained tumor material

- Patients must consent to undergo biopsies of CSCC lesions (Groups 2 and 4 only)

- Surgical or radiological treatment of lesions contraindicated

Key Exclusion Criteria:

- Ongoing or recent (within 5 years) evidence of significant autoimmune disease that
required treatment with systemic immunosuppressive treatments, which may suggest risk
for immune-related adverse events

- Prior treatment with an agent that blocks the PD-1/PD-L1pathway

- Prior treatment with a BRAF inhibitor

- Prior treatment with other immune-modulating agents within fewer than 4 weeks prior to
the first dose of cemiplimab, or associated with immune-mediated adverse events that
were ≥ grade 1 within 90 days prior to the first dose of cemiplimab, or associated
with toxicity that resulted in discontinuation of the immune-modulating agent.
Examples of immune-modulating agents include therapeutic vaccines, cytokine
treatments, or agents that target cytotoxic T-lymphocyte antigen 4 (CTLA-4), 4-1BB
(CD137), or OX-40.

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

- Immunosuppressive corticosteroid doses (>10 mg prednisone daily or equivalent) within
4 weeks prior to the first dose of cemiplimab

- Infection with human immunodeficiency virus (HIV) and/or chronic/active infection with
hepatitis B virus or hepatitis C virus

- History of non-infectious pneumonitis within the last 5 years

- Allergic reactions or acute hypersensitivity reaction attributed to antibody
treatments

- Known allergy to doxycycline or tetracycline

- Patients with a history of solid organ transplant

- Any medical co-morbidity, physical examination finding, or metabolic dysfunction, or
clinical laboratory abnormality that renders the patient unsuitable

Other protocol-defined inclusion/exclusion criteria apply