Biomarker (BM) evaluations in the phase III AVAglio study of bevacizumab (Bv) plus standard radiotherapy (RT) and temozolomide (T) for newly diagnosed glioblastoma (GBM).

Abstract

2023^ Background: Bv plus 1st-line standard of care (SoC; T+RT) achieved a PFS benefit in the AVAglio phase III, randomized, double-blind, placebo [P]-controlled trial in patients (pts) with newly diagnosed GBM. AVAglio includes BM evaluation to identify pts benefiting most from Bv. Analysis of plasma VEGF-A and VEGFR-2 was prioritized based on encouraging findings in Bv trials in several tumor types. Methods: AVAglio includes an optional, exploratory correlative BM analysis; participating pts provided informed consent for BMs. Baseline (BL) plasma samples were analyzed using the Roche IMPACT platform, based on multiplex ELISA technology. Pts were dichotomized according to BM levels using either Q1, median or Q3 cut-offs. Potential interactions between BL BM levels and PFS were tested using Cox regression analyses. Results: Of 921 patients enrolled, 571 (62%) were evaluable in the BM study. Baseline characteristics and PFS outcome were comparable in the ITT and BM-evaluable populations. Median BL VEGF-A and VEGFR-2 levels were 77.0 pg/mL and 12.6 ng/mL, respectively. No significant interaction for PFS was seen at α=0.025. Conclusions: The potential predictive (VEGF-A, VEGFR-2) and prognostic (VEGF-A) value seen in breast, pancreatic and gastric cancers was not apparent in BL BM samples from AVAglio using a median, Q1 or Q3 cut-off. Additional plasma and tumor BM analyses are ongoing. Clinical trial information: NCT00943826. [Table: see text]