Circulating cytokines and angiogenic factors (CAFs) in patients with advanced non-clear cell renal cell carcinoma treated with sunitinib: Results from a phase II clinical trial.

Abstract

483 Background: Development of hypertension (HTN) during VEGF-directed therapies is associated with improved overall survival (OS) in patients (pts) with clear-cell renal cell carcinoma. There is paucity of data about the molecular determinants of response and survival outcomes in non-clear cell renal cell carcinoma (nccRCC) pts treated with targeted therapies. We investigated CAFs and correlated them and HTN with outcomes of nccRCC pts treated with sunitinib in a phase II trial. Methods: Using a bead-based multiplex assay (Luminex), levels of 30 CAFs (including mediators of inflammation, angiogenesis, immunity, and metastasis) were measured prior to start of sunitinib therapy (baseline) and at 4 weeks after completion of cycle 1. Sunitinib benefit was defined as having partial response (PR) or stable disease (SD) by RECIST lasting ≥4 months. Cox proportional hazards regression models were used to assess the association between CAFs, HTN, and survival outcomes. The Kaplan-Meier method was used to estimate progression-free survival (PFS) and OS. Results: Fifty-seven pts [papillary (27), chromophobe (5), unclassified (8), collecting duct/medullary carcinoma (6), sarcomatoid (7), others (4)] were evaluable. Median follow up was 59.1 months (range, 30.6-82.6); 43 pts (75%) have died and 14 (25%) were alive at last follow up. Sunitinib benefit was seen in 21 pts (8 papillary, 4 chromophobe, 3 unclassified, 3 others, 2 collecting duct/medullary carcinoma, 1 sarcomatoid); 2 pts were not evaluable for response. Median PFS was 2.9 months (95% CI, 1.4-5.5) and median OS 16.8 months (95% CI, 10.7-27.4). 29 pts developed HTN during the first cycle, but there was no significant association between HTN and OS, PFS or sunitinib benefit. Elevated baseline levels of GRO, TGFα, sTNF-RI, sVEGF-R2 and IL-8 were correlated with higher risk of death. Conclusions: In this phase II trial in pts with advanced nccRCC, we found no significant association between HTN and PFS, OS, or sunitinib benefit. Candidate CAFs were identified that could be incorporated into prognostic and predictive models for validation in future studies in nccRCC.