Cosibelimab for CSCC in Patients With Kidney Transplant or Hematologic Malignancy

Inclusion Criteria: * COHORT A: Participant must have a history of kidney transplant (at least 6 months prior to enrollment). (A history of more than one kidney transplantation is permitted.) * COHORT B: Participant must have a diagnosis of a hematologic malignancy, including chronic myeloproliferative neoplasm (CMN) or an indolent non-Hodgkin's lymphoma (NHL), or multiple myeloma (MM). * Examples of indolent non-Hodgkin's lymphomas (NHL), including but not limited to: * Chronic lymphocytic leukemia (CLL) * Small cell lymphocytic lymphoma (SLL) * Follicular lymphoma (FL) * Lymphoplasmacytic lymphoma * Waldenström macroglobulinemia * Marginal zone lymphoma * Mantle cell lymphoma, indolent variety * Cutaneous T-cell lymphoma (mycosis fungoides and Sézary syndrome) * Examples of chronic myeloproliferative neoplasms (CMN), including but not limited to: * Chronic myelogenous leukemia (CML) * Polycythemia vera (PV) * Primary myelofibrosis * Essential thrombocythemia (ET) * Chronic neutrophilic leukemia * Chronic eosinophilic leukemia * Examples of myeloma, including but not limited to: * Multiple myeloma (MM) * Smoldering myeloma * Participants must have histologically or cytologically confirmed diagnosis of cutaneous squamous cell carcinoma (CSCC). * Note: Mixed histology is acceptable (e.g. basosquamous, squamous cell carcinoma with adnexal differentiation), and other histologic variants (sarcomatoid carcinoma, spindle cell carcinoma, poorly di…