Phase III randomized trial of cetuximab (CET) plus either brivanib alaninate (BRIV) or placebo in patients (pts) with metastatic (MET) chemotherapy refractory K-RAS wild-type (WT) colorectal carcinoma (CRC): The NCIC Clinical Trials Group and AGITG CO.20 trial.

Abstract

386 Background: The anti-EGFR monoclonal antibody CET has improved survival in pts with MET, chemotherapy refractory, K-RAS wild type (WT) CRC. The addition of BRIV, a tyrosine kinase inhibitor targeting vascular endothelial and fibroblast growth factor receptors (VEGFR/FGFR), to CET has shown encouraging activity in an early phase clinical trial. Methods: Pts with MET CRC previously treated with combination chemotherapy were randomized 1:1 to receive CET 400 mg/m2 IV loading dose followed by weekly maintenance of 250 mg/m2 plus either BRIV 800 mg PO daily (Arm A) or placebo (Arm B). Pts may have had 1 prior anti-VEGF, but no prior anti-EGFR therapy. The trial was amended shortly after opening to enrol K-RAS WT pts. Primary endpoint was overall survival (OS). Results: From 02/2008 to 02/2011, 750 pts were randomized (376 in Arm A and 374 in Arm B). Demographics: median age=64 (range 27-88); male=64%; ECOG 0:1:2 (%)=32:58:10; >3 prior chemotherapy regimens=92%; prior anti-VEGF therapy=41%; K-RAS WT=97%. Median OS in the intent-to-treat population was 8.8 months in Arm A and 8.1 months in Arm B, hazard ratio (HR)=0.88; 95% CI=0.74 to 1.03; p=0.12. Median progression-free survival (PFS) was 5.0 months in Arm A and 3.4 months in Arm B, HR=0.72; 95% CI=0.62 to 0.84; p<0.0001. Both partial responses (13.6% vs 7.2%, p=0.004) and stable disease (50% vs 44%) were higher in Arm A. Incidence of any ≥grade 3 adverse event (AE) was 78% in Arm A and 53% in Arm B. Most frequent ≥grade 3 AEs were fatigue (25%), hypertension (11%) and rash (10%) in Arm A, vs fatigue (11%), rash (5%) and dyspnea (5%) in Arm B. Time to deterioration of physical function was shorter and global quality of life scores were lower in Arm A vs Arm B. Pts received ≥90% dose intensity of CET=57% in Arm A vs 83% in Arm B; of BRIV/placebo=48% in Arm A vs 87% in Arm B. Conclusions: Despite positive effects on PFS and objective response, the combination of CET+BRIV did not significantly improve OS in pts with MET, chemotherapy refractory, K-RAS WT CRC. AEs were consistent with those reported for each drug given as monotherapy.