Randomized phase II study of sunitinib + CXCR4 inhibitor LY2510924 versus sunitinib alone in first-line treatment of patients with metastatic renal cell carcinoma.

4547 Background: Sunitinib is a standard first-line treatment for patients (pts) with metastatic renal cell carcinoma (RCC). CXCR4 and its only known ligand, SDF-1, are both overexpressed in tumor and vascular cells of clear cell RCC. LY2510924 is a selective peptide antagonist of CXCR4. We compared the results of open-label treatment with LY2510924 + sunitinib vs sunitinib alone. Methods: Previously untreated metastatic clear cell RCC pts were randomized (2:1) to receive standard-dose sunitinib (50 mg qd for 4 weeks [wk], then 2 wk off) + LY2510924 (20 mg sc, qd) (Arm A) or sunitinib alone (Arm B). Pts were evaluated (per RECIST v.1.1) every 8 wk. The primary analysis was done when all pts completed 72 wk of treatment, discontinued, progressed, or died and compared progression-free survival (PFS) between arms using a Bayesian time to event analysis incorporating prior information about sunitinib along with the trial data. PFS was also analyzed using the hazard ratio (HR) with only trial data. The Bayesia...