Pembrolizumab for metastatic melanoma in a renal allograft recipient with subsequent graft rejection and treatment response failure: a case report

BACKGROUND: Transplant patients were excluded from the pivotal phase III trials of checkpoint inhibitors in metastatic melanoma. The efficacy and toxicity profiles of checkpoint inhibitors in this cohort of patients are not well described. To the best of our knowledge, this is the first case report of a renal transplant patient with stage IV melanoma treated with a programmed cell death protein 1 checkpoint inhibitor that led to both treatment failure and renal graft rejection. CASE PRESENTATION: We present a case of a 58-year-old white man with a long-standing cadaveric renal transplant who was diagnosed with a B-Raf Proto-Oncogene, Serine/Threonine Kinase wild-type metastatic melanoma. He was treated with first-line pembrolizumab but experienced subsequent graft failure and rapid disease progression. CONCLUSIONS: This case highlights the risks associated with the administration of checkpoint inhibitors in patients with a renal transplant and on immunosuppressive therapy. More specifically, it adds to the literature indicating that, compared with the cytotoxic T-lymphocyte-associated protein 4 inhibitor ipilimumab, anti-programmed cell death protein 1 agents are more likely to lead to renal graft failure. Additionally, these novel immunotherapeutics may be ineffective in transplant patients; therefore, clinicians should be very aware of those risks and carefully consider selection of agents and full disclosure of the risks to their patients.