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, 4, and 6)
* 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