Efficacy of Second-line Targeted Therapy for Renal Cell Carcinoma According to Change from Baseline in International Metastatic Renal Cell Carcinoma Database Consortium Prognostic Category.

Background: We hypothesized that changes in International Metastatic Renal Cell Carcinoma Database Consortium (IMDC) prognostic category at start of second-line therapy (2L) for metastatic renal cell carcinoma (mRCC) might predict response.
Objective: To assess outcomes of 2L according to type of therapy and change in IMDC prognostic category.
Design, Setting, and Participants: We performed a retrospective review of the IMDC database for mRCC patients who received first-line (1L) VEGF inhibitors (VEGFi) and then 2L with VEGFi or mTOR inhibitors (mTORi). IMDC prognostic categories were defined before each line of therapy (favorable, F; intermediate, I; poor, P). Data were analyzed for 1516 patients, of whom 89% had clear cell histology.
Intervention: All included patients received targeted therapy for mRCC.
Outcome Measurements and Statistical Analysis: Overall survival (OS), time to treatment failure, and response to 2L were analyzed using Cox or logistic regression.
Results and Limitations: At start of 2L, 60% of patients remained in the same prognostic category; 9.0% improved (3% I → F; 6% P → I); 31% deteriorated (15% F → I or P; 16% I → P). Patients with the same or better IMDC prognostic category had a longer time to treatment failure if they remained on VEGFi compared to those who switched to mTORi (adjusted hazard ratio [AHR] ranging from 0.33 to 0.78, adjusted p<0.05). Patients who deteriorated from F to I appeared more likely to benefit from switching to mTORi (median OS 16.5 mo, 95% confidence interval [CI] 12.0-19.0 for VEGFi; 20.2 mo, 95% CI 14.3-26.1 for mTORi; AHR 1.53, 95% CI 1.04-2.24; adjusted p=0.03).
Conclusions: Changes in IMDC prognostic category predict the subsequent clinical course for patients with mRCC and provide a rational basis for selection of subsequent therapy.
Patient Summary: The pattern of treatment failure might help to predict what the next treatment should be for patients with metastatic renal cell carcinoma.
(Copyright © 2016 European Association of Urology. Published by Elsevier B.V. All rights reserved.)