Combination checkpoint blockade for metastatic cutaneous malignancies in kidney transplant recipients

BACKGROUND: Immune checkpoint blockade has emerged as a highly effective treatment for patients with metastatic melanoma and cutaneous squamous cell carcinoma. Nivolumab blocks the interactions between programmed cell death protein 1 and programmed death ligand 1 allowing for activation of a latent immune response against the malignancy. Ipilimumab binds to and blocks cytotoxic T-lymphocyte-associated protein 4, alleviating the negative regulation of T-cell activation that is mediated by that checkpoint. Combination therapy with nivolumab and ipilimumab is associated with longer overall survival at 5 years compared with nivolumab monotherapy. Solid organ transplant recipients have a significantly higher risk of malignancies compared with the general population. There is limited data surrounding the efficacy of combination immunotherapy in solid organ transplant recipients, as these patients were excluded from seminal trials due to risk of organ rejection. CASE PRESENTATIONS: Here we present four cases of combination immunotherapy in kidney transplant recipients. Three patients had metastatic melanoma, and one patient had metastatic cutaneous squamous cell carcinoma. Two patients had radiographic responses from immunotherapy, one patient had stable disease, and one patient had disease progression. Only one patient had biopsy-proven rejection. At last follow-up, three patients had functioning grafts, though one required hemodialysis after treatment, and one patient succumbed to disease, but graft function remained intact throughout her course. CONCLUSIONS: These cases describe the use of ipilimumab and nivolumab combination immunotherapy for cutaneous malignancies in kidney transplant recipients. They highlight the potential to preserve kidney graft function while effectively treating the disease.