Intralesional Cemiplimab for Adult Patients With Cutaneous Squamous Cell Carcinoma or Basal Cell Carcinoma

This study is researching an experimental drug called cemiplimab. The study is focused on Cutaneous Squamous Cell Carcinoma (CSCC) and Basal Cell Carcinoma (BCC). The aim of the study is to evaluate the safety and tolerability (how your body reacts to the drug) of cemiplimab (also known as REGN2810). The first part of the study tested several different doses of cemiplimab given weekly for 12 weeks. The study is also looking at several other research questions, including: * What side effects may happen from taking the study drug * To see effect of cemiplimab on the tumor * How much study drug is in the blood at different times