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)