Study of Afatinib in Advanced Cutaneous Squamous Cell Carcinoma

Inclusion Criteria: * Age ≥ 18 years at the time of informed consent * ECOG performance status ≤2 * Adequate bone marrow, organ function and laboratory parameters: * ANC ≥ 1.0 × 109/L; * Hemoglobin ≥ 8 g/dL; * Platelets ≥ 75 × 109/L; * AST and ALT ≤5 × ULN * Calculated creatinine clearance \> 15mL/min by Cockroft-Gault formula * Histologic diagnosis of invasive cutaneous squamous cell carcinoma, that is deemed not appropriate for further surgical intervention and/or radiation therapy. Participants may have either locally advanced or metastatic disease. * At least 1 measurable lesion - either per RECIST 1.1 criteria, or for patients with externally visible cuSCC lesion(s) not measurable on imaging, at least one lesion ≥1 cm in longer diameter, amenable to digital photography with bi-dimensional measurements * Participants must have received prior immunotherapy with an anti-PD-1/PD-L1 antibody, if participant was deemed eligible (i.e., was not immunosuppressed or a transplant receipt, etc) * Immunosuppressed participant including those with concurrent autoimmune diseases and solid organ transplant recipients are eligible * Prior to first dose of study treatment, participant must be at least 2 weeks from any prior systemic therapy, major surgery or radiation * Able to undergo a pre-treatment and on-treatment tumor biopsy * Female participants of childbearing potential must have a negative serum or urine β-HCG test result. Female participants of childbearing potential and male p…