Metastatic Cutaneous Squamous Cell Carcinoma

D-TECT is a prospective, multicenter, non-interventional observational study investigating whether pretreatment D-dimer levels predict disease control in patients with locally advanced or metastatic cutaneous squamous cell carcinoma treated with cemiplimab in routine clinical care. D-dimers are routinely available laboratory markers related to activation of the coagulation system. Previous single-center data suggest that elevated pretreatment D-dimer levels may be associated with poorer disease control under cemiplimab. In D-TECT, a single pretreatment D-dimer value and prospectively collected routine clinical follow-up data will be analyzed to validate this association in a multicenter real-world setting. No study-specific treatment decisions, imaging procedures, or additional blood draws are mandated by the study.

The purpose of this research study is to test the safety and effectiveness of a tumor-infiltrating lymphocyte (TIL) cellular therapy, also called LN-145 or lifileucel, and chemotherapy in combination with Interleukin-2 (IL-2) to find out what effects, if any, the combination has on participants with Cutaneous squamous cell carcinoma (CSCC) or Merkel Cell Carcinoma (MCC) who were previously treated with immunotherapy. The names of the study interventions involved in this study are: * Tumor Infiltrating Lymphocytes (a type of cellular therapy) * Fludarabine and Cyclophosphamide (types of standard of care chemotherapy drugs) * Interleukin-2 (a type of recombinant, human glycoprotein)