ASCO GU 2018: Outcomes and Patterns of Disease Progression in Metastatic Renal Cell Carcinoma Patients Treated with Nivolumab

San Francisco, CA (UroToday.com) 
Background:
Nivolumab (nivo) has been approved for the treatment of refractory metastatic renal cell carcinoma (mRCC). Data regarding the characteristics and outcomes of patients who progress on nivo are lacking.

Methods:
The authors conducted a retrospective analysis of patients with clear cell mRCC who received nivo at Cleveland Clinic (2015-2017). Patients were divided into two groups:

1) Progressive disease (PD) group per RECIST v1.1 criteria or clinical PD 

2) Non progressive disease (NPD) group

Results:
Ninety patients (PD group n = 56, NPD group n = 34) with median age of 67 (33-83), 74% men, and 79% ECOG 0-1 were included. Patients had received 1 (44%), 2 (29%), or ≥ 3 (27%) prior systemic treatments, most commonly with sunitinib (71%), axitinib (39%) and pazopanib (33%). Patients 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%) patients developed PD per RECIST v1.1 whereas 5 (9%) patients had clinical PD. 

New organ sites of metastases were found in 20/55 (36%) patients; brain (8/20; 40%), liver (4/20; 20%), soft tissue (4/20; 20%), and locoregional metastasis (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 patients received treatment beyond progression with a median duration of 2.8 months (95% CI, 0.6-5.0) and 50% of patients 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:
Patients with PD on nivo have a higher incidence of hepatic metastases at baseline, and one third of these patients develop new sites of metastases at PD, most commonly in the brain.

Presented by: Haris Zahoor, Cleveland Clinic, Cleveland, OH, USA

Written by: Hanan Goldberg, MD, Urologic Oncology Fellow (SUO), University of Toronto, Princess Margaret Cancer Centre @GoldbergHanan, at the 2018 American Society of Clinical Oncology Genitourinary (ASCO GU) Cancers Symposium, February 8-10, 2018 - San Francisco, CA