A correlative biomarker analysis of the combination of bevacizumab and carboplatin-based chemotherapy for advanced nonsquamous non-small-cell lung cancer: results of the phase II randomized ABIGAIL study (BO21015).

Introduction: Avastin Biomarkers In lunG And 3D Innovative anaLysis (ABIGAIL), which is a phase II, open-label, randomized study, investigated correlations between biomarkers and best overall response to bevacizumab plus platinum-doublet chemotherapy for patients with advanced/recurrent non-small-cell lung cancer.
Methods: Patients received bevacizumab (7.5 or 15 mg/kg, 3-weekly until disease progression/unacceptable toxicity) plus carboplatin/gemcitabine or carboplatin/paclitaxel (maximum six cycles). Plasma samples (baseline/throughout treatment) were analyzed for vascular endothelial growth factor (VEGF)-A (baseline only), VEGF receptors (VEGFR-1/VEGFR-2), basic fibroblast growth factor, E-selectin, intercellular adhesion molecule-1, and placental growth factor (baseline only). Tumor samples (primary specimen) were analyzed for VEGF-A, VEGFR-1/VEGFR-2, neuropilin (NRP), and CD31. Response was evaluated at baseline and every 6 weeks (Response Evaluation Criteria in Solid Tumors).
Results: Patients were randomized to receive chemotherapy plus 7.5 mg/kg (n =154) or 15 mg/kg (n =149) bevacizumab. For the primary analysis, none of the baseline plasma biomarkers correlated with best overall response. Exploratory analyses showed that low VEGF-A levels were associated with longer progression-free survival (7.4 versus 6.1 months; hazard ratio, 1.57; 95% confidence intervals, 1.17 to 2.09; p = 0.002) and overall survival (19.8 versus 11.1 months; hazard ratio, 1.57; 95% confidence interval, 1.15-2.13; p = 0.004) compared with these in high baseline plasma VEGF-A levels. No plasma biomarkers changed significantly over time. No significant correlations were observed between tumor biomarkers and clinical outcomes. No new safety signals were observed.
Conclusion: Baseline and/or dynamic changes in plasma basic fibroblast growth factor, E-selectin, intercellular adhesion molecule-1, placental growth factor, VEGFR-1 and VEGFR-2, and tumor biomarkers did not correlate statistically with treatment outcomes for bevacizumab plus chemotherapy. Only baseline plasma VEGF-A was significantly correlated with progression-free survival/overall survival.