Outcomes and patterns of disease progression in metastatic renal cell carcinoma patients treated with nivolumab.

Abstract

654 Background: Nivolumab (nivo) has been approved for the treatment of refractory metastatic renal cell carcinoma (mRCC). Data regarding the characteristics and outcomes of patients (pts) who progress on nivo are lacking. Methods: A retrospective analysis of pts with clear cell mRCC who received nivo at Cleveland Clinic (2015-2017) was performed. Pts were divided into two groups; 1) PD group; pts with progressive disease (PD) per RECIST v1.1 or clinical PD, and 2) NPD group; pts with non-progressive disease on nivo. Results: Ninety pts (PD group n = 55, NPD group n = 35) with median age of 67 (33-83), 74% men, and 79% ECOG 0-1 were included. Pts had received 1 (44%), 2 (29%), or ≥ 3 (27%) prior systemic treatments, most commonly with sunitinib (71%), axitinib (39%) and pazopanib (33%). Pts in the PD group had a greater incidence of baseline liver metastases (PD, 40% vs. NPD, 14%; p = 0.01), with other baseline characteristics not significantly different. Median follow up was similar in both groups (PD group, 8.0 months (95% CI, 5.5-10.5) and NPD group, 7.1 months (95% CI, 4.9-9.3); p = 0.87). Median duration of treatment for PD group was 8.7 months (95% CI, 7.3-10.1) compared to 16.1 months (95% CI, 8.6-23.6) for NPD group (p = 0.02). In the PD group, 50 (91%) pts developed PD per RECIST v1.1 whereas 5 (9%) pts had clinical PD. New organ sites of metastases were found in 20/55 (36%) pts; brain (8/20; 40%), liver (4/20; 20%), soft tissue (4/20; 20%), and locoregional (4/20; 20%) were the most common new organ sites, whereas lungs, lymph nodes and pancreas were never involved at PD as new organ sites. Twelve pts received treatment beyond progression (TBP) with a median duration of TBP of 2.8 months (95% CI, 0.6-5.0) and 50% of pts had stable disease as their best response. Median overall survival (OS) and progression free survival (PFS) on nivo were 10.1 months (95% CI, 6.6-13.6) and 5.5 months (95% CI, 2.9-8.1), respectively. Conclusions: Pts with PD on nivo have a higher incidence of hepatic metastases at baseline, and one third of these pts develop new sites of metastases at PD, most commonly brain.