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I. Okamoto
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MINI 10 - ALK and EGFR (ID 105)
- Event: WCLC 2015
- Type: Mini Oral
- Track: Biology, Pathology, and Molecular Testing
- Presentations: 1
- Moderators:T. Yap, T. Li
- Coordinates: 9/07/2015, 16:45 - 18:15, Mile High Ballroom 1a-1f
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MINI10.10 - A Multicenter Prospective Biomarker Study in Afatinib-Treated Patients with EGFR-Mutation Positive Non-Small Cell Lung Cancer (ID 472)
17:40 - 17:45 | Author(s): I. Okamoto
- Abstract
- Presentation
Background:
Afatinib is an oral, irreversible ErbB family blocker and one of the key drugs for patients with EGFR mutation positive advanced non-small cell lung cancer (NSCLC). Although treatment with afatinib has a clinical benefit for these patients, such individuals inevitably develop drug resistance as with other TKIs. This is a multicenter prospective biomarker study to inform the usefulness of noninvasive liquid biopsy in the treatment of EGFR-tyrosine kinase inhibitors (EGFR-TKIs) and explore the molecular mechanism of acquired-resistance against afatinib.
Methods:
Eligible patients were EGFR-TKIs naïve and had histologically and cytologically confirmed stage IIIB/IV adenocarcinoma of the lung with activating EGFR mutations. Patients remained on afatinib treatment until disease progression or unacceptable toxicity. Tumor samples were collected upon before afatinib treatment and after disease progression. Plasma samples were collected upon before and during afatinib treatment (4 and 24 weeks after initiation) and after disease progression. DNA derived both from tumors and plasma was analyzed using Scorpion-ARMS (ARMS), digital PCR (dPCR) and next generation sequencing (NGS). We used a nanofluidic dPCR system (BioMark HD System; Fluidigm) with a digital chip to detect activating or resistance mutations of EGFR in a quantitative and highly sensitive manner. NGS on an Ion Torrent PGM device (Thermo Fisher Scientific) was applied to detect target molecules which contribute to the survival and growth of lung cancer cells. We compared the sensitivity of these methods in detection of EGFR activating mutations in plasma DNA.
Results:
A total of 35 EGFR mutation positive NSCLC patients were enrolled. Twenty one patients harbored a deletion in exon 19 and fourteen patients had an L858R missense mutation in exon 21. Twenty seven (77.1%) patients had an objective response. In plasma DNA obtained before afatinib treatment, dPCR and NGS detected EGFR activating mutations more sensitively compared with ARMS (83.9% v 58.1%; p <0.005, 74.2% v 58.1%; p =0.059, respectively). Concordance of EGFR activating mutations detected by dPCR and NGS was 26/31 (84%) (kappa value: 0.52). All of the mutation type detected by NGS on plasma DNA completely corresponded to that found in matching tumor tissue by NGS. As of March 2015, serial plasma DNA was analyzed in 9 patients. The copy number of activating mutation was markedly decreased in 5 of 9 patients.
Conclusion:
EGFR activating mutations in plasma DNA were frequently detected by dPCR or NGS. We will present the detailed data for monitoring mutation load in plasma DNA during the afatinib treatment.
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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
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ORAL17.03 - Biomarkers for Efficacy in JO25567 Study Evaluating Erlotinib plus Bevacizumab versus Erlotinib in Advanced NSCLC with EGFR Mutation (ID 306)
11:07 - 11:18 | Author(s): I. Okamoto
- Abstract
- Presentation
Background:
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
Methods:
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.
Results:
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.
Conclusion:
In this comprehensive predictive biomarker analysis, follistatin and leptin in blood were identified as potential biomarker candidates for E+B therapy.
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