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ORAL 17 - EGFR Mutant Lung Cancer (ID 116)
- Event: WCLC 2015
- Type: Oral Session
- Track: Treatment of Advanced Diseases - NSCLC
- Presentations: 1
- Moderators:P. Meldgaard, E. Felip
- Coordinates: 9/08/2015, 10:45 - 12:15, Four Seasons Ballroom F3+F4
ORAL17.03 - Biomarkers for Efficacy in JO25567 Study Evaluating Erlotinib plus Bevacizumab versus Erlotinib in Advanced NSCLC with EGFR Mutation (ID 306)
10:45 - 12:15 | Author(s): K. Tajima
Bevacizumab (B), an anti-vascular endothelial growth factor (VEGF) monoclonal antibody has been proven to provide additional efficacy benefit in combination with platinum-based chemotherapy for 1[st] line therapy of non-squamous non-small cell lung cancer (NSCLC). In JO25567 study, we observed that bevacizumab in combination with epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, erlotinib (E) also provided additional 6.3 months median progression free survival (PFS) in advanced EGFR mutation-positive non-squamous NSCLC. To try to understand this additional effect of bevacizumab, we investigated the predictive biomarkers related to angiogenesis comprehensively in JO25567 study. Clnical trials registry number: JapicCTI-111390
We evaluated the biomarkers in blood and tissue samples. All samples were collected before E+B or E treatment in JO25567 study. Angiogenesis related ligands and soluble receptors in serum were analyzed by multiplex, bead-based suspension array. Single nucleotide polymorphisms (SNPs) or variable number of tandem repeats (VNTR) of angiogenesis related genes were analyzed by direct sequencing or electrophoresis after PCR for blood sample. VEGF-A concentration in plasma were analyzed by Immunological Multi-Parametric Chip Technique (IMPACT) assay. Messenger RNA of genes related to angiogenesis in tumor tissue were quantitated by multiplex TOF-mass spectrometry (MassARRAY). Immunohistochemistry of neuropilin and exploratory proteomics analysis were planned for surgically resected tumor tissues. PFS were used as an efficacy variable of prediction. Multivariate Fractional Polynomial (MFP) and Subpopulation Treatment Effect Pattern Plot (STEPP) were used for biomarker screening.
One hundred fifty-two patients were treated with E+B or E in JO25567 study. We analyzed 26 ligands or soluble receptors in 134 serum samples. Follistatin and leptin were identified as potential biomarkers by MFP. The interaction p-value with adjustment of covariates for biomarker and efficacy was 0.0168 for follistatin and 0.0049 for leptin. STEPP suggested that high follistatin related to limited bevacizumab efficacy and low leptin related to higher bevacizumab efficacy. SNPs could be analyzed in 135 blood samples. In 12 SNPs and 1 VNTR of 8 genes, no gene related to bevacizumab efficacy. Plasma samples were collected from 105 patients. Median VEGF-A concentration of E+B group and E group were 18.0 pg/mL and 18.8 pg/mL respectively and was one sixth or more lower than previously reported breast and gastric cancers. Hazard ratio of E+B comparing with E for was 0.23 (95% CI: 0.09-0.60) for low plasma VEGF and was 0.56 (95% CI: 0.26-1.25) for high plasma VEGF. This trend was not consistent with previously reported studies. We analyzed mRNA expression from 24 surgical resected tumors and no predictive value was observed. Because of limited number of surgically resected tumors obtained, we couldn’t proceed exploratory proteomics analysis nor evaluate predictive value of neuropilin expression.
In this comprehensive predictive biomarker analysis, follistatin and leptin in blood were identified as potential biomarker candidates for E+B therapy.