Abstract
BACKGROUND: Immunotherapy with combination of nivolumab and ipilimumab is the current standard of care therapy for patients with renal cell carcinoma (RCC). However, there are currently no data describing the efficacy of this combination in papillary renal cell carcinoma with sarcomatoid dedifferentiation, a rare but highly aggressive entity. We present the first two cases of papillary RCC with sarcomatoid dedifferentiation that received nivolumab and ipilimumab as first-line therapy and experienced rapid and deep responses. CASE PRESENTATION: The first patient had papillary type 2 RCC with sarcomatoid and rhabdoid dedifferentiation metastatic to the lungs and lymph nodes. He achieved a complete response to frontline nivolumab plus ipilimumab at first restaging, with excellent tolerance. The second patient had papillary type 1 RCC with sarcomatoid dedifferentiation metastatic to the lymph nodes and pleura. She developed acute kidney failure following one infusion of frontline nivolumab plus ipilimumab, which was successfully treated with corticosteroids and a short course of hemodialysis. Her disease has remained under control without any further antineoplastic therapy. CONCLUSIONS: The combination of nivolumab plus ipilimumab can produce rapid and deep responses and should be considered as a therapeutic option in patients with papillary RCC with sarcomatoid dedifferentiation. Patients should be carefully monitored for immune-related adverse events, even after a single infusion of nivolumab plus ipilimumab.