In a large randomized study, the immunotherapy drug nivolumab, a checkpoint inhibitor, was shown to be a safe and effective therapy for kidney cancer even in patients who continued treatment after their disease progressed. Results of the phase III clinical study conducted by physician-scientists at multiple centers, including Roswell Park Cancer Institute (RPCI), will be presented at the American Society of Clinical Oncology (ASCO) 52nd Annual Meeting in Chicago.

While drugs are traditionally discontinued at the first evidence of disease progression, immunotherapy response patterns differ from responses to other treatments. In this large clinical study (Checkmate-025) conducted in the treatment-refractory setting of metastatic renal cell carcinoma (RCC), 406 patients received nivolumab (brand name Opdivo). Of the patients who progressed on nivolumab, 153 continued treatment beyond progression and 145 were not treated beyond progression. Patients without progressive disease were excluded from analysis. Fourteen percent of those who continued treatment experienced a 30% or greater reduction in their tumors. Additionally, patients who continued treatment survived 28.1 months, compared with 15 months for those who did not continue therapy.

"This study demonstrates that patients who continued treatment with nivolumab after their disease progressed may have demonstrated a delayed immune response that ultimately prolonged survival," says Saby George, MD, FACP, Associate Professor of Oncology in the Department of Medicine at Roswell Park and senior author of the study. "These findings indicate that the new immunotherapy checkpoint inhibitor drugs merit further study to establish different clinical guidelines with a goal to optimize patient benefit. It is important to translate such findings into clinical practice guidelines in order to have better outcomes."

Study: Treatment beyond progression with nivolumab (nivo) in patients (pts) with advanced renal cell carcinoma (aRCC) in the phase III CheckMate 025 study," is ASCO 2016 abstract 4509, Monday, June 6.