PD-1 in Patients With Advanced Basal Cell Carcinoma Who Experienced Progression of Disease on Hedgehog Pathway Inhibitor Therapy, or Were Intolerant of Prior Hedgehog Pathway Inhibitor Therapy

Key Inclusion Criteria: * Confirmed diagnosis of invasive BCC * Progression of disease on hedgehog inhibitor (HHI) therapy or intolerance of prior HHI therapy * At least 1 measurable lesion * ≥18 years of age * Hepatic function, renal function, bone marrow function in defined lab-value-ranges * Anticipated life expectancy \>12 weeks * Consent to provide archived tumor biopsy material (all patients) * Group 2: consent to undergo research biopsies * Group 2: must not be a candidate for radiation therapy or surgery * Comply with study procedures and site visits * Sign Subject Information Sheet and Informed Consent Form Key Exclusion Criteria: * Ongoing or recent significant autoimmune disease * Prior treatment with specific pathway-blockers (PD-1/PD-L1) * Prior treatment with immune-modulating agents within 28 days before cemiplimab * Untreated brain metastasis that may be considered active * Immunosuppressive corticosteroid doses (\>10mg prednisone) within 28 days prior to treatment with cemiplimab * Active infections requiring therapy, including HIV, hepatitis * Pneumonitis within the last 5 years * Cancer treatment other than radiation therapy, including investigational or standard of care, within 30 days prior to treatment with cemiplimab * Documented allergic reactions or similar to antibody treatments * Concurrent malignancies other than BCC, other than those with negligible risk of metastases or death * Any acute or chronic psychiatric problems * Having received a soli…