Cemiplimab-rwlc for Unresectable Locally Recurrent and/or Metastatic CSCC

Inclusion Criteria: * Histologically confirmed diagnosis of invasive Cutaneous Squamous Cell Carcinoma (CSCC) * Immunocompromised patients with invasive CSCC. Immunocompromised patients are defined as: (a) History of HIV with CD4 counts \>/= 200 and no AIDS-defining illness (b) History of treated or active hematologic malignancies including lymphoma, Hodgkin's disease, chronic lymphocytic leukemia, chronic myeloid leukemia, multiple myeloma, and myeloproliferative neoplasm. * At least 1 lesion that is measurable by study criteria by RECIST 1.1. Externally visible cutaneous Squamous Cell Cancer (SCC) target lesion(s) greater than \>10 mm, bi-dimensional measurements of the external lesion(s) with a color photograph may be used as target lesions. * Eastern Cooperative Oncology Group (ECOG) performance status 0-2 * Laboratory values as defined per protocol * Ability to sign informed consent * Ability and willingness to comply with scheduled visits, treatment plans, laboratory tests, and other study-related procedures. * CSCC not amenable to surgery or radiation therapy such as unresectable tumors determined by surgeons, surgical morbidity unacceptable by the patients, inability to deliver radiation safely determined by radiation oncologists, or radiation related toxicities unacceptable by the patients. Note: In lieu of individual consults performed during screening, it will suffice to document the contraindication of surgery and radiation therapy via a clinic note from the inv…