Autoimmune rhabdomyolysis and a multiorgan display of PD-1 inhibitor induced immune related adverse events during treatment of metastatic melanoma

BACKGROUND: Programmed death-1 (PD-1) inhibitors are among the immunotherapies that have revolutionized our approach to treating several cancers. These novel agents act by blocking PD-1 receptor/PD-1 ligand interactions that would otherwise allow tumor cells to evade host immune destruction by inhibiting response of cytotoxic T-lymphocytes. They are overall well tolerated, though they have been associated with a constellation of immune mediated adverse events (irAEs). CASE PRESENTATION: We present a case of rare nivolumab mediated adverse events in a patient with nodular recurrence of melanoma. The patient presented with rhabdomyolysis and shortly thereafter developed a constellation of immune-mediated organ derangements. This case further demonstrates the utility and effectiveness of steroid therapy in the setting of irAEs despite our patient’s eventual poor clinical outcome. While PD-1 inhibitors have revolutionized the treatment of several cancers, they require vigilance by the clinician for early detection and treatment of uncommon but potentially fatal irAEs. CONCLUSIONS: PD-1 inhibitors are now widely used in a multitude of cancer types including melanoma, advanced non-small cell lung cancer, metastatic renal cell carcinoma, and Hodgkin lymphoma amongst others. While these agents are often well tolerated, they are associated with a unique profile of immune-related toxicities that can cause significant morbidity and mortality. Education of both patients and healthcare providers is essential for diagnosis and treatment of these adverse events early in their course. This case highlights the uncommon but potentially serious PD-1-associated toxicity of myopathy and rhabdomyolysis along with other organ involvement and is directly applicable to use of these agents in patients with advanced cancers.