On-treatment progression-free survival analysis of aflibercept-FOLFIRI treatment within 28 days of progression in metastatic colorectal cancer: Updated efficacy results from the VELOUR study.
469 Background: The phase III VELOUR study demonstrated that adding the novel antiangiogenic agent aflibercept (known as ziv-aflibercept in the United States) to FOLFIRI in patients with metastatic colorectal cancer previously treated with oxaliplatin significantly improved overall survival, progression-free survival (PFS), and overall response rate versus placebo-FOLFIRI. We performed an additional analysis of PFS “on-treatment,” censoring events that occurred more than 28 days after last treatment dose. Methods: Patients were randomized to receive aflibercept 4 mg/kg or placebo every 2 weeks in combination with FOLFIRI. An independent review committee determined progression based on radiologic review. PFS was estimated using Kaplan-Meier analysis, with censoring of events after the last dose plus 28 days. Treatment groups were compared using a log-rank test stratified by ECOG performance status and prior bevacizumab therapy. Hazard ratio (HR) and confidence interval (CI) were estimated using a Cox proportional hazard model. Results: On-treatment PFS results are shown in the Table. Patients on aflibercept-FOLFIRI showed significantly increased on-treatment PFS compared with patients on placebo-FOLFIRI. More patients were censored in the aflibercept arm due to adverse events, thus decreasing the number of events. Conclusions: On-treatment PFS with aflibercept-FOLFIRI was significantly increased compared with placebo-FOLFIRI, which is consistent with the PFS benefit observed in the primary analysis. Clinical trial information: NCT00561470. [Table: see text]