Detection Of EGFR T790M Mutation Research Articles

85PD - Ultrasensitive detection of EGFR T790M mutation by droplet digital PCR (ddPCR) in TKI naïve non-small cell lung cancer (NSCLC) harboring EGFR mutation: Results of the nationwide program Biomarkers France of the French Cooperative Thoracic Intergroup (IFCT)

85PD - Ultrasensitive detection of EGFR T790M mutation by droplet digital PCR (ddPCR) in TKI naïve non-small cell lung cancer (NSCLC) harboring EGFR mutation: Results of the nationwide program Biomarkers France of the French Cooperative Thoracic Intergroup (IFCT)

Abstract 760: Detection of EGFR T790M mutation by ddPCR in untreated NSCLC patients: Correlation with clinical outcome

Abstract Background: Activating EGFR mutations are associated with response to first generation tyrosine kinase inhibitors (TKI) that significantly increased PFS and OS in NSCLC patients. However, almost invariably, patients relapse while in treatment with TKI, mostly for the presence of EGFR T790M mutation. New second and third generation EGFR inhibitors active against T790M are now under development with very promising results. To date it is not known if the presence of T790M (and its amount) at diagnosis influences clinical outcome of patients with activating EGFR mutation. Methods: We analysed 50 cases with NSCLC. 48 patients harbour TKI sensitizing mutation in either exon 19 (N=24) or 21 (N=19). 2 EGFR wt patients (blinded to the investigator) were analysed in parallel. These patients were screened by ddPCR for the presence of T790M mutation using Biorad QX200 Droplet Digital PCR System. We used rough DNA extract from FFPE sections after deparaffinization and proteinase K digestion, as available in pathology unit for daily diagnosis. Results: 12 samples failed to amplify, maybe due to the poor quality of DNA. 13 samples produced results, but were excluded for the analysis because of too low number of calls retrieved. T790M mutation was detected in a significant proportion of remaining cases. Among the latter, 4 patients were sampled after TKI treatment and here the percentage of T790M were higher compared to those patients not treated [0.65% - 28% vs 0.019% - 1.65%, respectively]. One out four of these patients was not detected by routinely method of sequencing (Sanger or RT-PCR). T790M positive samples harboured mutations affecting exon 19 or 21 in equal manner. Conclusions: ddPCR has proven to be a sensitive method to detect T790M mutation, although the quality of DNA could affect the results. The system has been challenged for specificity an sensitivity and the results proved to be clinically relevant. The correlation between the T790M positivity and clinical outcome will be available and we plan to define a ddPCR threshold value which can help in selecting those patients who are likely to have early recurrence under first generation TKI and that could therefore be directly shifted to second or third generation inhibitors. Citation Format: Monica Ganzinelli, Eliana Rulli, Elena Tamborini, Adele Busico, Giuseppe Lo Russo, Giulia Corrao, Milena Vitali, Marina Chiara Garassino, Massimo Broggini, Mirko Marabese. Detection of EGFR T790M mutation by ddPCR in untreated NSCLC patients: Correlation with clinical outcome [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 760. doi:10.1158/1538-7445.AM2017-760

P3.02b-010 Urine Detection of EGFR T790M Mutation in Non-Small-Cell Lung Cancer: An Outcomes and Total Cost of Care Analysis: Topic: EGFR Biomarkers

Third-generation tyrosine kinase inhibitors (3rd-TKIs) have proven effective in patients with EGFR T790M who progress on prior EGFR TKI therapy. Median progression-free survival (PFS) on a 3rd-TKI was 9-10 months for T790M+ patients compared to 2-4 months for T790M- patients. PFS is similar regardless of the specimen used to assess T790M (tissue, plasma, or urine). Using simulation analytics, the primary study aim was to assess the cost effectiveness of a urine-testing strategy (UTS) versus a tissue-testing strategy (TTS) for T790M detection in patients with EGFR-positive lung adenocarcinoma and progression on prior TKI therapy. Analytics followed International Society for Pharmacoeconomics and Outcomes Research (ISPOR) and Society for Medical Decision Making (SMDM) guidelines for Good Modeling Practices and Consolidated Health Economic Evaluation Reporting Standards (CHEERS) for reporting findings. Outcomes and economic implications were assessed from the perspective of a third-party US payer, stratified by government versus commercial fee rates. Endpoints were PFS, overall survival (OS), direct medical resources used (biopsies, chemotherapy, post-progression) and related costs. Data sources were published reports of randomized drug trials and current data, which includes accuracy results of tissue versus urine testing (Trovagene, San Diego, CA), Medicare fee schedules, and available adjustments for fees in commercial markets. A state-transition analysis and Markov model tracked patients from stable disease, progression, and to death. Full univariate and multivariate sensitivity analyses were performed to assess the robustness of findings and factors that most influenced outcomes and costs. Median PFS after treatment with 3rd-TKI was 3.4 months if tumor testing is T790M- versus 9.7 months if T790M+. Because urine testing can be used in patients for whom biopsy cannot be performed or when tissue testing reveals indeterminate results, PFS and OS were slightly increased using the UTS. UTS resulted in avoidance of a biopsy procedure, potential complications, and tissue-based molecular testing in approximately 48% of patients, leading to a 2- to 10-fold total cost savings relative to the unit cost for a urine test. Within the robust variations in input parameters, the cost of a biopsy procedure/complications and tissue-based molecular testing were the most influential factors. UTS is a dominant scenario to TTS by saving costs and improving patient experience (e.g., PFS/OS, and reduction in biopsy related complications). This result is based on LEVEL I evidence from a large, randomized trial that showed PFS is similar among patients regardless of urine versus tissue testing for T790M mutation status.

5LBA - Plasma EGFR T790M mutation detection in NSCLC patients using a combined exosomal RNA and circulating tumor DNA qPCR assay

5LBA - Plasma EGFR T790M mutation detection in NSCLC patients using a combined exosomal RNA and circulating tumor DNA qPCR assay

Development of an efficient scoring system for detection of EGFR-T790M mutation in non-small cell lung cancer patients treated with EGFR-tyrosine kinase inhibitors.

e20599Background: Secondary T790M mutation of epidermal growth factor receptor (EGFR) accounts for approximately half of all cases of acquired resistance to EGFR-tyrosine kinase inhibitors (TKIs) i...

134O_PR: Plasma ctDNA analysis for detection of EGFR T790M mutation in patients (pts) with EGFR mutation-positive advanced non-small cell lung cancer (aNSCLC)

134O_PR: Plasma ctDNA analysis for detection of EGFR T790M mutation in patients (pts) with EGFR mutation-positive advanced non-small cell lung cancer (aNSCLC)

Abstract A31: Assessment of EGFR mutations in matched urine, plasma and tumor tissue in NSCLC patients treated with rociletinib (CO-1686)

Abstract Background: The acquisition of suitable tumor tissue is a challenge for a significant fraction of late-stage NSCLC patients who require EGFR testing to inform choice of therapy. An alternative for these patients could be the assessment of EGFR mutations in circulating tumor DNA (ctDNA). In this study, we examined the detection of EGFR T790M mutation in ctDNA from urine, assessed urine sample requirements, and compared the results with contemporaneously matched tumor tissue and plasma in TIGER-X (NCT01526928), a Phase 1/2 clinical study of rociletinib in previously treated mutant EGFR patients with advanced NSCLC. Rociletinib is an oral, potent, small-molecule irreversible tyrosine kinase inhibitor that selectively targets mutant forms of EGFR, including T790M, L858R and Del(19), while sparing wild-type EGFR. Methods: 63 Stage IIIB/IV NSCLC patients enrolled in either Phase 1 or 2 components of TIGER-X and representing all therapeutic dose groups consented to optional urine collection. Maximum sample volumes were 100 mL for urine and 2 mL for plasma. To maximize assay sensitivity in urine, samples containing the recommended sample volume of ≥90 mL (≥ 90% of maximum in this study) were evaluated; all samples received were processed to assess this recommendation. Urinary and plasma ctDNA were tested for mutations by the same EGFR assays using a sensitive and quantitative short footprint assay method that employs a mutation enrichment step followed by next generation sequencing. Results: Urine volumes ranged from 8-100 mL with a median DNA yield of 313 ng (N = 63). The median DNA yield was 299 ng for urine specimens with volume <90 mL (N = 44) and 392 ng for specimens with the previously recommended volume of ≥90 mL (N = 19). 45/63 patients (71%) were positive for T790M by urine in comparison to 47/63 (75%) by central lab testing of tissue. Using tissue as the reference, the positive percent agreement (PPA) between urine and tumor T790M test results was 93% (13/14) using urine samples with volumes ≥90 mL and 73% (34/47) when the urine volume was <90 mL. The PPA between plasma and tissue T790M test results was 80% (42/51). Overall, there were 13 cases that were tumor T790M+/urine T790M-, and 7 cases that were urine T790M+/tumor T790M-. Six urine T790M+/tumor T790M- cases were also T790M+ in plasma. Two additional urine T790M+ cases could not be analyzed by the tumor test due to insufficient material. Serially matched urine and plasma assessments were performed on a subset of patients (N = 15). In most cases, the urine and plasma serial profiles mirrored one another. A rapid drop in urine and plasma mutant EGFR levels was seen in almost all patients who experienced clinical benefit from rociletinib. Conclusions: The analysis of ctDNA from urine identified a similar proportion of T790M+ patients as tissue-based testing with highest PPA amongst patients with urine volumes ≥90 mL. Discordant samples between urine and tissue that were not identified by the tumor test may be explained by tumor heterogeneity and/or inadequate biopsy. EGFR mutation detection from urine increases with urine volume and DNA yields and should be considered as a viable approach, particularly when tumor tissue is not available. Lastly, monitoring urine ctDNA T790M mutations longitudinally with baseline and post-therapy sampling could be clinically useful to determine benefit from therapy. Citation Format: Shirish Gadgeel, Chris Karlovich, Vlada Melnikova, Lecia V. Sequist, D. Ross Camidge, Heather Wakelee, Maurice Perol, Geoffrey R. Oxnard, Karena Kosco, Cecile Rose T. Vibat, Elaina Mann, Shannon Matheny, Lindsey Rolfe, Mitch Raponi, Mark G. Erlander, Karen Reckamp. Assessment of EGFR mutations in matched urine, plasma and tumor tissue in NSCLC patients treated with rociletinib (CO-1686). [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2015 Nov 5-9; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2015;14(12 Suppl 2):Abstract nr A31.

36O - Detection of EGFR T790M Mutation in Urinary Circulating Tumor Dna From Metastatic Non-Small Cell Lung Cancer Patients

36O - Detection of EGFR T790M Mutation in Urinary Circulating Tumor Dna From Metastatic Non-Small Cell Lung Cancer Patients

Abstract C196: EGFR mutation detection in ctDNA isolated from NSCLC patient plasma; a cross-platform comparison of leading technologies.

Abstract Emerging evidence suggests that circulating tumor DNA (ctDNA) provides an alternative diagnostic sample when surgical biopsies are inaccessible, and could enable disease diagnosis, frequent assessment of disease progression, and almost real-time monitoring of the emergence of resistance mutations. We hypothesized that novel highly sensitive technologies enable EGFR T790M mutation detection in ctDNA from patients that had previously been treated with and become resistant to EGFR-TKIs. We have used 3 technologies to assess T790M mutation detection rate. Samples comprised patients with sensitizing EGFR mutations and wild type EGFR patients who had been previously treated with EGFR TKI therapies. In approximately 50% of EGFR mutation positive cases, acquired resistance to EGFR-TKIs is mediated by an EGFR T790M mutation. Reference data for T790M mutations from tumor material was unavailable.We undertook a comprehensive cross-technology comparison of three technology platforms: ARMS based detection using the Roche cobas EGFR mutation detection kit; digital droplet PCR using the BioRad ddPCR instrument (by MolecularMD) and bead based digital PCR using the Inostics BEAMing technology for the detection of T790M mutations. In total, 135 frozen plasma samples, obtained from 2 clinical studies, were used to estimate T790M detection rates in ctDNA. Within the study group, 72 samples were taken from EGFR mutation positive patients, of which around 36 (expected range 28-44) would be expected to have T790M mutations, the remaining samples would be expected to be T790M negative. Each individual patient plasma sample was split and evaluated across multiple platforms. In addition, the suitability of 3 ctDNA preparation kits (cobas Circulating DNA Isolation kit, QIAamp Circulating Nucleic Acid kit and QIAamp DNA Mini kit) in terms of DNA yield was evaluated. The QIAamp Circulating Nucleic Acid kit and cobas Circulating DNA Isolation kit were equally effective in preparing ctDNA from plasma samples. Overall, concordance of EGFR T790M mutation status was high between all 3 methods. In addition, the false positive rate in the known EGFR mutation negative cases was low for all 3 methods. However, differences were seen in the rate of false negative results (assay sensitivity) between methods. DNA preparation kits specifically designed for use with ctDNA samples are preferable to other methods. Current technologies for the detection of T790M mutations in ctDNA, where patient tumor material is not available, still require further development to increase detection rates in these samples. Citation Information: Mol Cancer Ther 2013;12(11 Suppl):C196. Citation Format: Helen Brown, Roz Brant, Simon Dearden, Suzanne Jenkins, Kenneth Thress, Alain Horvais, Ruth March, J. Carl Barrett. EGFR mutation detection in ctDNA isolated from NSCLC patient plasma; a cross-platform comparison of leading technologies. [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference: Molecular Targets and Cancer Therapeutics; 2013 Oct 19-23; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2013;12(11 Suppl):Abstract nr C196.

Highly sensitive and noninvasive detection of epidermal growth factor receptor T790M mutation in non-small cell lung cancer

BackgroundEpidermal growth factor receptor (EGFR) T790M mutation is associated with EGFR tyrosine kinase inhibitors resistance in non-small cell lung cancer (NSCLC). However, the tissue availability and technical feasibility limits the genotyping of EGFR T790M mutation in the clinical setting. The current study is, therefore, designed to develop a blood-based approach to detect the EGFR T790M mutation in advanced NSCLC patients. MethodsThe detection of EGFR T790M mutation is based on the principle of mutant-enriched PCR. We assessed the basic performance efficiency of this method, and confirmed its clinical applicability. EGFR T790M mutation in the plasma samples obtained from 33 patients with gefitinib-resistant NSCLC was analyzed by the both mutant-enriched PCR and direct sequencing. ResultsThe sensitivity of this method for the detection of EGFR T790M mutation was as low as 0.1%. In the 33 subjects whose samples were analyzed, the mutant-enriched PCR indentified more EGFR T790M mutation than direct sequencing (36.4% vs. 6.1%, P=0.005), and the EGFR T790M mutation was more frequent in patients with EGFR activating mutations than those without EGFR activating mutations (62.5% vs. 11.8%, P=0.004). Patients with EGFR T790M mutation have a better prior efficacy of gefitinib compared to those without EGFR T790M mutation due to the occurrence of the EGFR activating mutations. ConclusionThe blood-based mutant-enriched PCR is an ideal noninvasive monitoring system for detecting EGFR T790M mutation for clinical application.