Nivolumab has demonstrated a substantial objective response rate and was well tolerated in people with metastatic non-clear cell renal cell carcinoma (non-ccRCC) who had stopped responding to treatment. The results of this multicentre study will be reported at the 2017 Annual Meeting of the American Society of Clinical Oncology (ASCO) this week.
Twenty-three patients from three centres were identified as having histologically-confirmed non-clear cell RCC and were given at least one dose of nivolumab for metastatic RCC between 2015 and 2017. The analysis focused on patient and treatment characteristics, objective response, and adverse events. Most common non-clear cell RCC histologies were unclassified (48%) and papillary (44%). At diagnosis, 65% had metastatic disease, most (74%) had undergone nephrectomy, and had received one (74%) or more than one (26%) prior systemic therapy (sunitinib, pazopanib, or axitinib). After a median follow-up duration of 6.5 months and eight nivolumab doses, median progression-free survival was 4.2 months and median overall survival was not reached. Among 21 patients evaluable for best response, six (29%) experienced a partial response and four (19%), stable disease. Median time to best response was 5.1 months and median duration of response had not been not reached at the time of analysis. Most common adverse events were fever (13%) and fatigue (13%).
The researchers said, “The results demonstrated that patients with renal cell carcinoma of non-clear-cell histology exhibit a substantial objective response rate to nivolumab. This 29% rate was comparable to the objective response rate of 25% observed with nivolumab in the CheckMate025 trial. Nivolumab was also well tolerated in this patient population. The analysis provided the first retrospective data suggesting clinical benefit of nivolumab in patients with non-clear-cell renal cell carcinoma. The results support its use in this patient population. This was a small retrospective analysis and we are validating these findings in a larger multi-institution cohort with longer clinical follow-up.”