430 Background: Third-line targeted therapy efficacy in metastatic renal cell carcinoma (mRCC) is not well characterized and many funding bodies do not provide reimbursement for it. Methods: The International mRCC Database Consortium (IMDC) consists of consecutive patient series from 25 cancer centers. It was queried for specific sequences of targeted therapy and third-line therapy. Kaplan Meier estimates were used for survival. Cox proportional hazards models were used to adjust hazard ratios for confounders. Patients that stopped second-line therapy were divided into two groups: those that went onto third-line therapy and those did not. Results: 4,050 patients were treated with first-line targeted therapy, of which 2,011 (49.6%) had second-line therapy and 879 (21.7%) had third-line targeted therapy. The most common third-line therapies were everolimus 25%, sorafenib 14%, sunitinib 13%, temsirolimus 11%, pazopanib 10%, and axitinib 6%. IMDC prognostic groups at third-line therapy initiation were 6% favorable risk, 67% intermediate risk, and 27% poor risk. Overall response rate for third-line therapy was 10.5% and 50.9% had stable disease in those patients that were evaluable. Median PFS was 5.1 months (95% CI, 4.5-5.7) and median OS from third-line therapy initiation was 12.0 months (95% CI, 10.7-12.9). Patients stopping second-line therapy that move on to third-line therapy vs. those that do not receive third line therapy have a median OS from stopping second-line therapy of 13.1 vs. 2.3 mons (p<0.0001). When adjusted for second-line IMDC prognostic criteria and KPS at second-line treatment cessation, patients who do receive third-line therapy have a HR of death of 0.41 (95% CI, 0.32-0.52; p<0.0001) compared to those that do not receive third-line therapy. This may be in part due to patient selection. To further limit bias, when excluding patients that live less than 3 months after second-line therapy cessation, the adjusted HR was similar. Conclusions: Third-line targeted therapy has demonstrated activity and is prevalent in use. Further studies are required to determine appropriate sequencing.
A prospective, open-label, interventional study protocol to evaluate treatment efficacy of nivolumab based on serum-soluble PD-L1 concentration for patients with metastatic and unresectable renal cell carcinoma
