Identifying candidates for immunotherapy with cemiplimab to treat advanced cutaneous squamous cell carcinoma: an expert opinion

Cutaneous squamous cell carcinoma (CSCC) is the second most common skin malignancy in white-skinned populations. Only a minority of patients (<5%) develop advanced disease, but this is often difficult to treat and characterised by a poor prognosis. Cemiplimab, a fully human IgG4 monoclonal antibody against programmed cell death-1 receptor, is indicated for advanced (i.e. locally advanced or metastatic) CSCC. Although the definition of metastatic CSCC is clear, there is currently no agreed definition of locally advanced CSCC. In recent guidelines, locally advanced CSCC was described as non-metastatic CSCC that is unlikely to be cured with surgery, radiotherapy or combination treatment. A multi-disciplinary advisory group of Italian CSCC experts was convened to develop criteria to assist in identifying appropriate candidates for cemiplimab therapy in advanced CSCC, based on the literature and clinical experience. In locally advanced CSCC, absolute, or mandatory, criteria for the use of cemiplimab are deep invasion, multiple lesions without defined margins, inadequate surgical excision margins and multiple recurrences, whereas relative criteria include large lesions, in critical or functionally significant areas and that are surgically complex. In addition, physicians should consider patient willingness/preferences (an absolute criterion), and their age and health status/comorbidities (relative criteria). It is hoped that these proposed absolute and relative criteria will help guide rational identification of patients who will receive maximum benefit from immunotherapy, while more clinical data accumulate.