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  • 1
    In: Blood, American Society of Hematology, Vol. 120, No. 21 ( 2012-11-16), p. 2549-2549
    Abstract: Abstract 2549 Background: BCR-ABL1 mutation testing is recommended for CML and Ph+ ALL patients who fail first line tyrosine kinase inhibitor (TKI) therapy or who have a suboptimal response to therapy. BCR-ABL1 mutations in the kinase domain (KD) of ABL1 account for at least 40–50% of all TKI resistant cases. Rare mutations such as E123Q and T212R in the regulatory domain of ABL upstream of the kinase domain have also been reported to lead to resistance to imatinib. The current gold standard for BCR-ABL1 mutation detection is Sanger sequencing, which has an analytical sensitivity of ∼10–30%. Based on recent findings that mass spectrometry can identify low level BCR-ABL1 mutations that confer clinical resistance in patients sooner than Sanger sequencing, it is likely useful to have a significantly more sensitive BCR-ABL1 test than Sanger sequencing. Although commercial NGS cancer panels have included ABL1 in the region of interest, ABL1 resistance mutations should be sequenced from BCR-ABL1 fusion transcripts instead of being sequenced from genomic DNA as in the commercial panels. Here we developed a fusion transcript based BCR-ABL1 mutation assay on the scalable and cost-effective Ion Torrent platform that has 1–5% sensitivity and comprehensive coverage of the kinase domain, regulatory domain, and the SH2/SH3 domains. The assay was designed to detect both the major and minor BCR-ABL1 fusion gene products and can also detect the micro BCR-ABL1 fusion product accounting for over 99% of all CML and Ph+ ALL patients. Methods: RT and long range PCR was performed to amplify BCR-ABL1 e1, e13, and e14 fusion transcripts and the PCR products were enzymatically fragmented and ligated with Ion Torrent sequencing adaptors. Size-selected libraries were quantified, pooled, amplified with OneTouch system and sequenced with Ion Torrent PGM. Sequencing data was analyzed with Torrent Suite 2.2 and the associated variant caller with variant frequency cutoff adjusted to 1%. Results: Initial work with cell lines harboring the T315I mutation in both e1 and e14 BCR-ABL1 transcript types diluted into wild type cell line demonstrated that Ion Torrent NGS can detect T315I at least down to 1%. In a set of 17 blinded clinical samples, Ion Torrent NGS not only identified all the mutations found by Sanger sequencing but additionally identified rare imatinib resistant mutations such as K357E (MMD-3) present at 7.6%; this mutation was previously reported in patient CD34+CD38-stem cells (Table 1). This patient also expressed the E255K resistance mutation; in patients, the presence of multiple resistance mutations has been shown to be an important predictor of poor response. Understanding whether compound mutations are present in cis or in trans may be important in understanding therapy resistance. For patient MMD-9, although both the predominant mutation G250E (79%) and subclone E255V(12.6%) were identified by both Sanger sequencing and NGS, only Ion Torrent was able to show that the two mutations were on different reads, indicating that the mutations are on different alleles. The BCR-ABL1 Ion Torrent based assay reads DNA fragments between 150–200bps in size and can identify cis and trans mutations from individual fragments with this read length, which is not possible by Sanger sequencing. In MMD-9, another low frequency subclone F359C (3%) was detected by only NGS and may have important implications due to its reported sensitivity to dasatinib and not imatinib or nilotinib. Similarly, in MMD-10 the E255V predominant mutation was identified by both NGS and Sanger sequencing, while the F317L mutation with a low frequency of 1.70% was solely detected by NGS. In this patient, a combination of dasatinib and nilotinib treatment may be required to eliminate the dasatinib sensitive E255V dominant clone and F317L nilotinib sensitive subclone. Ion Torrent NGS was also capable of identifying and calling the 35 base pair 475 insertion from 4 samples (MMD-2 and 8–10), only two of which were detected by Sanger sequencing. In our ongoing study, the low-level mutations not detected in Sanger sequencing will be confirmed with analyses on the MiSeq platform and mutation enrichment methods. Additional patient samples representing 30 CML patients will be analyzed and presented. Disclosures: Wong: MolecularMD: Equity Ownership.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2012
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  • 2
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 73, No. 8_Supplement ( 2013-04-15), p. 3509-3509
    Abstract: Introduction: LKB1 (liver kinase B1)/STK11 (serine-threonine kinase 11) is a tumor suppressor that encodes a serine/threonine kinase which negatively regulates the mTOR (mammalian target of rapamycin) signaling pathway. Somatic mutations in LKB1 occur most notably in lung adenocarcinoma, cervical cancers and melanoma. Inactivation of LKB1 is caused by point mutations, homozygous deletions or promoter methylation. LKB1 mutation status is a predictive marker for responsiveness to both MEK and PI3K inhibitors. We have developed next-generation sequencing (NGS), Sanger sequencing and immunohistochemistry (IHC) assays to assess LKB1 mutation and protein expression status in a set of FFPE patient specimens. Methods: For NGS, we used the Ion Torrent platform to sequence a 4.4kb region of interest (ROI) around LKB1. A combination of TorrentSuite and in-house tools were used for alignment, variant calling and prioritization of variants. Sanger sequencing was used to validate the presence and absence of variants with a frequency of at least 10% that were identified by NGS. An IHC assay was developed using a commercially available antibody. These assays were validated using a combination of cell lines, a genetically engineered mouse model and FFPE tissue for specificity, sensitivity, reproducibility and concordance. Results: 35 patient FFPE tissues from a variety of tumors including cervix, endometrium, pancreas, skin and lung were evaluated for LKB1 mutation status using NGS and IHC methods. About 96% of the coding region of LKB1 had sufficient sequencing coverage (read depth & gt;500x) to reliably call low frequency somatic variants. Analytical validation using cell line dilutions demonstrated that our NGS assay is able to detect single base changes with frequencies as low as 2-5%, and small indels with frequencies as low as 5-10%. We identified 9 coding and splice site variants in our preliminary analysis of 18/35 of the FFPE specimens. We compared the variants in 7 of these FFPE samples to the variants identified in these samples by Sanger sequencing, and found 100% concordance between the variant calls, for NGS variants with frequencies greater than 20%. Sanger sequencing in the remaining FFPE samples is ongoing, and lower frequency NGS variants will be confirmed by other methods. We compared the validated NGS variants with the IHC results to examine the correlation of sequencing results with protein expression analysis. In our preliminary analysis of the first 18 FFPE samples, all of the samples with an IHC score of zero or one (IHC negative) had either a nonsense (n=1) or missense (n=4) variant in STK11. Conclusions: Our data suggest that accurate assessment of LKB1 status may require complementary methods including NGS and IHC methods. Citation Format: Kimberly Pelak, Jennifer Wright, Zhenyu Yan, Agus Darwanto, Weihua Liu, Peng Fang, Jin Li, Sabita Sankar, Chad Galderisi. Complementary analysis of LKB1/STK11 mutation and protein expression status using next-generation sequencing, Sanger sequencing and immunohistochemistry. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3509. doi:10.1158/1538-7445.AM2013-3509
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
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    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2013
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  • 3
    In: Blood, American Society of Hematology, Vol. 132, No. Supplement 1 ( 2018-11-29), p. 1558-1558
    Abstract: In Ph+ ALL, the absence of detectable disease has shown prognostic value for a reduced risk of relapse and improved survival. However, as the level of undetectable disease is determined by the lower limit of detection of the test in use, standardization of such an endpoint for a drug regulatory submission is critical. To date, no tyrosine kinase inhibitor (TKI) has received approval for the newly diagnosed Ph+ ALL adult patient population in the US. Takeda (Millennium Pharmaceuticals, Inc.) is conducting a phase 3, randomized, open-label, multicenter efficacy study comparing ponatinib versus imatinib, administered in combination with reduced-intensity chemotherapy, in participants with newly diagnosed Ph+ ALL (NCT03589326). The primary endpoint for this study is minimal residual disease (MRD)-negative complete remission (CR), where MRD-negativity is defined as a BCR-ABL:ABL raw ratio of ≤0.01% (MR4.0) in bone marrow aspirate samples at the end of induction. Patients who achieve post-induction ponatinib or imatinib maintained MRD-negative CR will potentially delay or avoid stem cell transplantation. Previously, for the purposes of initiating and monitoring treatment free remission or discontinuation of TKI therapy in chronic phase CML patients, we developed and validated the MRDx® BCR-ABL Test which is an FDA authorized test for the quantitative detection of BCR-ABL e13a2 or e14a2 transcripts. This test will be used in this study and reports BCR-ABL:ABL levels on the International Scale (IS) with traceability to the World Health Organization (WHO) first International Genetic Reference Panel and with a limit of detection below 0.0032% (i.e., MR4.5). Similarily, for assessment of the e1a2 (p190) BCR-ABL:ABL transcripts, we developed and validated a one-step reverse transcription, quantitative polymerase chain reaction (RT-qPCR) test in order to accurately and precisely assess all clinical decision points and disease levels for this study. Because of the lack of available reference material for e1a2, a droplet digital PCR (ddPCR) based test was co-developed to quantify e1a2 BCR-ABL copy numbers in bone marrow aspirates, as well as in peripheral blood samples (to allow assessment of concordance). e1a2 in vitro transcribed RNA calibrators assign copy numbers to determine the e1a2 BCR-ABL:ABL raw % ratios of unknown samples. The e1a2 RT-qPCR test exceeded an analytical sensitivity of MR4.5 (0.0032% raw ratio of BCR-ABL:ABL) with a dynamic linear range from MR4.5 to MR1.0. The test also includes cell line derived RNA assay controls formulated to 10%, 0.1% and 0.01% BCR-ABL:ABL, necessary for decision points in the clinical trial. Validation studies included limit of blank, limit of detection (LOD), limit of quantification, assay range, analytical specificity, repeatability, reproducibility (multi-day, multi-operator, and multi-instrument), and accuracy by comparison to a reference method (ddPCR). The validation of the e1a2 RT-qPCR test with bone marrow aspirate samples was conducted with 1 µg RNA inputs per well and LOD was also verified with 0.5 µg RNA input per well. In conclusion, the validated e1a2 RT-qPCR test allows for accurate standardization of BCR-ABL:ABL measurement across multiple centers in an international Phase 3 study. The e1a2 RT-qPCR test data will be used to assess the primary endpoint in the first registrational trial to be conducted in newly diagnosed Ph+ ALL adult patients. Disclosures Drafahl: MolecularMD, Corp: Employment. Smith:MolecularMD, Corp: Employment. Graham:MolecularMD, Corp: Employment. Glynn:MolecularMD, Corp: Employment. Spittle:MolecularMD, Corp: Employment. Verrow:Takeda (Millennium Pharmaceuticals, Inc.): Employment. Rivera:Takeda (Millennium Pharmaceuticals, Inc.): Consultancy. Srivastava:Takeda (Millennium Pharmaceuticals, Inc.): Employment. Hawkins:MolecularMD, Corp: Employment. Galderisi:MolecularMD, Corp: Employment, Equity Ownership.
    Type of Medium: Online Resource
    ISSN: 0006-4971 , 1528-0020
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    Language: English
    Publisher: American Society of Hematology
    Publication Date: 2018
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  • 4
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 75, No. 15_Supplement ( 2015-08-01), p. 4261-4261
    Abstract: Introduction: The Oncomine® Cancer Panel (OCP) is designed to simultaneously detect and report hotspot mutations, Copy Number Variants (CNVs) and gene fusions in 143 genes with minimal DNA/RNA sample input. The OCP utilizes the AmpliSeq™ library preparation chemistry for the Ion Torrent™ Next Generation Sequencing (NGS) platform, in combination with data annotations by the Oncomine® Knowledgebase. Here we report analytical validation of OCP. Methods: DNA and RNA, extracted from the FFPE processed GM12878, was used as the negative control to evaluate the specificity of OCP. A RNA sample containing multiple oncogenic gene fusions, and a DNA sample containing multiple hotspot SNV and indels were used as the positive control. Fresh DNA from cancer cell lines (HCC1143 or NCI-H2122) along with DNA from matched normal cell lines, HorizonDx NGS standards TruQ-1, TruQ-2, several engineered FFPE samples with gene fusions or copy number changes, and 26 clinical FFPE samples of a variety of solid tumor types (lung, breast, colon, ovary, stomach, uterus and larynx) were used to evaluate the OCP performance. The analysis of the sequencing data was primarily performed with the OCP pipeline integrated with Oncomine® Knowledgebase from Life Technologies, supplemented by the MolecularMD proprietary pipeline. Only the genetic alterations with clinical utility were selected as the final output from the data pipeline. Of these detected by OCP, the SBS and indels were confirmed by the Illumina TruSeq, Ion Torrent AmpliSeq commercial cancer panels, or by Sanger sequencing. Any CNVs detected were confirmed by FISH, if possible, and detected fusions were confirmed by RT-PCR or FISH. Results: No clinically relevant genetic alterations were detected from the negative control FFPE-GM12878, indicating the high specificity of the OCP. High specificity was achieved, in part, using stringent filters, which removed error prone regions from analysis. The LOD for SBS and short indel detection was 5%, as assessed by TruQ-1 and TruQ-2, each containing 15 variants. While the exact LOD for gene fusion detection is currently under evaluation, the 100%, 50% and 20% fusion were detected in the RNA samples from serially diluted EML4-ALK or SL34A2-ROS1 fusion into the FFPE-GM12878 RNA. Four known gene amplifications (MYC, CCND1, MDM2, AKT1) with CNV from 5.4X to 14.5X in HCC1143, and a 15.7X MYC amplification in NCI-H2122 were detected. In addition, an EML4-ALK.E13A20 fusion was detected in a lung cancer FFPE sample, and confirmed by FISH. The analytical sensitivity and the specificity of the OCP are currently assessed with 26 clinical samples and three engineered FFPE samples. Conclusions: These results demonstrate the high sensitivity and specificity of OCP. With as little as 10 ng RNA and 20 ng DNA, OCP provides comprehensive screening of patient FFPE tumor specimens for the detection of a broad spectrum of clinically relevant genetic alterations. Citation Format: Peng Fang, Zhenyu Yan, Weihua Liu, Jennifer Biroschak, Paul Labrousse, Jennifer Wright, Cindy Spittle, Chad Galderisi, Li Jin. Oncomine® Cancer Panel: simultaneous detection of clinically relevant hotspot mutations, CNVs, and gene fusions in solid tumors. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4261. doi:10.1158/1538-7445.AM2015-4261
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
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    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2015
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  • 5
    In: Clinical Cancer Research, American Association for Cancer Research (AACR), Vol. 13, No. 20 ( 2007-10-15), p. 6136-6143
    Abstract: Purpose: Imatinib induces a complete cytogenetic response (CCR) in most chronic myeloid leukemia patients in chronic phase. Although CCR is usually durable, a minority of patients relapse. Biomarkers capable of predicting those CCR patients with a higher risk of relapse would improve therapeutic management. Experimental Design: To assess whether changes in BCR-ABL RNA levels are a prognostic biomarker predictive of relapse, we regularly monitored transcript levels [every 3 months (median)] in 90 patients with CCR during 49 months (median) of imatinib therapy. Results: Throughout follow-up, the 20 patients with eventual relapse had higher transcript levels than the durable responders. Major molecular response (MMR; & gt;3-log reduction of BCR-ABL RNA) was attained by 76 patients (12 with subsequent relapse) and was a significant predictor of prolonged relapse-free survival (P = 0.0008). A minimal 0.5-log increase in transcripts (before relapse; experienced by 42 patients, 16 with subsequent relapse) conveyed a significantly shorter relapse-free survival (P = 0.0017). Loss of MMR (transcript increase to & lt;2.5-log reduction, before relapse; experienced by 33 patients, 11 with subsequent relapse) was also predictive of shortened relapse-free survival (P = 0.0003). A complete molecular response (undetectable transcripts by nested PCR) was attained by 28 MMR patients (one with subsequent relapse) and conveyed a significantly prolonged relapse-free survival (P = 0.0052). Conclusions: In chronic myeloid leukemia patients with an imatinib-induced CCR, a minimal half-log increase in BCR-ABL RNA (including loss of MMR) is a significant risk factor for future relapse. The achievement of a complete molecular response imparts longer progression-free survival than the achievement of an MMR.
    Type of Medium: Online Resource
    ISSN: 1078-0432 , 1557-3265
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    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2007
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  • 6
    Online Resource
    Online Resource
    American Association for Cancer Research (AACR) ; 2015
    In:  Cancer Research Vol. 75, No. 15_Supplement ( 2015-08-01), p. 4925-4925
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 75, No. 15_Supplement ( 2015-08-01), p. 4925-4925
    Abstract: Introduction: Plasma cell-free circulating tumor DNA (ctDNA) has the potential to serve as a noninvasive surrogate to determine tumor genotype and monitor treatment response. Here we report the analytical validation of the Ion AmpliSeq v2 Cancer Panel (ACP) in plasma ctDNA samples. Methods: Mutations were assessed using the ACP, designed to survey 2800 mutations in 50 cancer-related genes. TruQ reference standards were used to determine LOD. Healthy donor and cancer patient plasma samples were used for other studies. Eight libraries were barcoded and sequenced with PGM sequencing 200 kit v2 on a 318 v2 chip. The sequencing data were analyzed with a combination of Torrent Suite 3.4.2, VarScan, our proprietary analysis pipeline and IGV. The background noise level of hotspot nt positions was calculated from multiple runs of known wild type DNA. In order to increase the sensitivity of the assay to detect low-level mutation, a custom program was developed to detect variants clearly different from background noise (95% confidence) and not reported by the two variant callers. PCR methods were used for concordance testing. Results: The performance characteristics of the AmpliSeq v2 Cancer Panel were demonstrated in 1) Minimum DNA input and LOD: With 10 ng DNA input, 43/43 and 42/43 expected mutations were detected at 2.5% or 1%, respectively. With 1 ng DNA input, 42/43 and 40/43 expected mutations were detected at 2.5% and 1%, respectively. 2) Coverage: The mean library coverage for 40 plasma libraries was 2912x with only 5 non-critical regions below 250x coverage. 3) Baseline error rate: 95% of 2290 hot-spots for SBS showed & lt;0.5% background error frequency assessed in 10 healthy control ctDNA samples. The mean background error frequency plus two folds of SD falls below 0.5% for 91% of SBS hot-spots. 4)Precision: All mutations expected for TruQ6 were detected in 4 independent runs at observed allele frequencies with 0.6% mean SD and 0.1% mean deviation from the true value. A 2% TP53 mutation R174W was reproducibly detected in a lung cancer plasma sample in 2 independent runs. 5) Concordance study: Consistent results were observed for 3 positive (Allele Freq 40%, 3% and 0.2%, respectively) and 3 negative melanoma plasma samples previously genotyped by AS-PCR for Braf V600E/K mutations. Additional cancer patient ctDNA samples are being assessed for concordance in the detection of other mutations. Conclusions: The ACP offers a useful tool for comprehensive somatic mutation profiling in ctDNA. The limit of detection is 1-2% mutation frequency for most mutations with slight variation across different nucleotide positions. The low concentration of ctDNA obtained from plasma samples can present a challenge. Less than 10 ng DNA input may result in allele drop out for low level mutations due to the inefficient amplification of multiplex PCR compared with PCR methods using a short length single amplicon. Higher DNA input to rescue allele drop-out is under evaluation. Citation Format: WeiHua Liu, Zhenyu Yan, Candice L. Horn, Fabio Nunes, Steven M. Bray, Philip J. Ebert, Peng Fang, Jennifer Biroschak, Cindy Spittle, Chad Galderisi, Jin Li. Liquid biopsy using the ion AmpliSeq v2 cancer panel. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4925. doi:10.1158/1538-7445.AM2015-4925
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
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    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2015
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  • 7
    In: Journal of Thoracic Oncology, Elsevier BV, Vol. 11, No. 2 ( 2016-02), p. S21-S22
    Type of Medium: Online Resource
    ISSN: 1556-0864
    Language: English
    Publisher: Elsevier BV
    Publication Date: 2016
    detail.hit.zdb_id: 2223437-8
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  • 8
    In: Head & Neck, Wiley, Vol. 31, No. 6 ( 2009-06), p. 829-832
    Type of Medium: Online Resource
    ISSN: 1043-3074 , 1097-0347
    URL: Issue
    Language: English
    Publisher: Wiley
    Publication Date: 2009
    detail.hit.zdb_id: 2001440-5
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  • 9
    Online Resource
    Online Resource
    American Association for Cancer Research (AACR) ; 2013
    In:  Cancer Research Vol. 73, No. 8_Supplement ( 2013-04-15), p. 3490-3490
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 73, No. 8_Supplement ( 2013-04-15), p. 3490-3490
    Abstract: Introduction: EGFR T790M mutation leads to treatment resistance in ∼50% of NSCLC patient undergoing TKI treatment. Early detection of the emergence of this resistance mutation allows for tailoring of the treatment regimen. Detection of EGFR T790M requires higher sensitivity techniques than those needed to detect EGFR activating mutations, and quantitative measurement of T790M may also provide value in monitoring disease progression. Here we demonstrate that our proprietary amplicon next-generation sequencing (NGS) on Ion Torrent PGM provides an attractive solution for T790M detection with the advantage of high sensitivity, specificity, and quantification capability. Methods: We developed a proprietary library prep method for amplicon sequencing on the Ion Torrent PGM. Ion Torrent barcode sequences were refined in our validation to minimize barcode cross contamination. This optimization of barcodes allows for accurate mutation quantification, especially critical for variants with a frequency below 1%. This also added the benefit of higher throughput and lower cost. We employ this non-enrichment method to quantitatively measure T790M. DNA from the NCI-H1975 cell line was serially diluted into wild-type NA19240 DNA to determine the limit of detection (LOD), sensitivity, specificity, accuracy and reproducibility of the method. We also used reference FFPE DNA from HorizonDx to validate the accuracy and robustness of the assay. We further validated the test by comparing the performance of our NGS method with ddPCR using the same sample set (serially diluted H1975 into wild-type DNA controls). Results: Our data demonstrated that the LOD for T790M is 0.2%. And the method could reproducibly identify variants at these frequencies. With an input of 10ng of the HorizonDx FFPE DNA, we measured T790M frequency at 6.7%, which is concordant with the 6.5% mutation frequency reported by HorizonDx. We cross-validated our NGS assay with ddPCR, and the mutation frequencies detected by both platforms are nearly identical, and have a regression coefficient of 0.9995, with comparable LOD of 0.2%. Furthermore, our NGS assay allows us to detect other variants located in this amplicon, e.g. SNP Q787Q, with LOD at 1%. The phasing status of compound mutations can also be determined by this assay. To further improve the sensitivity, an enrichment method was developed, and the enriched T790M was sequenced by PGM. This method can semi-quantitatively measure T790M frequency with LOD of 0.03%. Conclusion: Our EGFR T790M NGS assay provides a unique option to reliably quantify T790M down to 0.2% with low DNA input. This highly sensitive and specific detection capability may enable earlier detection of emerging therapeutic resistance, particularly if FFPE results reported here extend to a more accessible specimen type, i.e. plasma circulating DNA, amenable to periodic patient monitoring. Citation Format: Agus Darwanto, Peng Fang, Zhenyu Yan, Weihua Liu, Kim Pelak, Jessica Kristof, Sabita Sankar, Cynthia Spittle, Chad Galderisi, Jin Li. Highly sensitive detection of EGFR T790M on Ion Torrent PGM. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3490. doi:10.1158/1538-7445.AM2013-3490
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
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    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2013
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  • 10
    In: Cancer Research, American Association for Cancer Research (AACR), Vol. 73, No. 8_Supplement ( 2013-04-15), p. 3229-3229
    Abstract: Introduction: The TruSeq Amplicon Cancer Panel (TSACP), a highly multiplexed targeted resequencing assay for use on the Illumina MiSeq platform, is designed for detecting the hotspot mutations in 212 Regions of Interest (ROI) from 48 cancer related genes. Here we report our validation study on the reproducibility, sensitivity and the specificity of detecting single base substitutions and small indels by the TSACP. Methods: We used well characterized cancer cell lines harboring clinically relevant variants as positive controls and HapMap samples NA12878 and NA19240 as wild type control samples. DNA from 8 cancer cell lines was serially diluted into the control DNA NA12878 for validating the Limit of Detection (LOD) of the TSACP assay. A total of 41 FFPE patient specimens representing a variety of cancer types were analyzed in a blinded fashion to evaluate the analytical sensitivity and specificity. DNA quality was assessed using a qPCR assay. With no gold standard available as a reference method to detect mutations with comparable sensitivity, concordance testing was performed using the Ion AmpliSeq Cancer Panel. Variants detected by both panels were considered as true positives. Variants that were only covered by one of the two panels were confirmed by a third method, either Sanger sequencing for variants with frequencies above 10% or a custom Ion TargetSeq Assay for variants with frequencies below 10%. Data were analyzed using MiSeq Reporter software and our proprietary analysis pipeline. In addition to reporting hotspots mutations, we also report “Critical Variants” such as non-synonymous coding mutations and splicing site mutations that fall within the ROI. Results: 95% of our ROIs were sequenced at minimum of 0.2X normalized coverage. A cell line dilution study showed that the LOD of confirmed variants is 5%. DNA extracted from 4 of the 41 FFPE specimens failed the template QC by qPCR and failed in the subsequent sequencing run. A total of 124 unique critical variants, including single base substitution, single- or multi- base (up to 21bp) deletion, one- or two- base insertion, were identified in the cancer cell lines and 37 qualified FFPE samples. The intra-assay and inter-assay reproducibility was ≥96%. Using our proprietary analysis pipeline, the analytical sensitivity and specificity for the FFPE samples were both 99%. One false negative of TSACP was identified by the Ion AmpliSeq Cancer Panel and was further confirmed by Sanger sequencing. This allele drop-off occurred as a result of the capture probe falling on a SNP. Homopolymer indels in KIT and STK11 were accurately identified with the Illumina sequencing chemistry. Conclusions: These studies demonstrate that the TSACP assay is highly specific and sensitive and is suitable for screening patient FFPE tumor specimens for a spectrum of clinically relevant somatic mutations. Citation Format: Peng Fang, Zhenyu Yan, Weihua Liu, Agus Darwanto, Kim Pelak, Kim Anoe, Cynthia Spittle, Sabita Sankar, Chad Galderisi, Jin Li. Validation of Illumina TruSeq Amplicon Cancer Panel with concordance testing using Ion AmpliSeq Cancer Panel and other methods. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 3229. doi:10.1158/1538-7445.AM2013-3229
    Type of Medium: Online Resource
    ISSN: 0008-5472 , 1538-7445
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    Language: English
    Publisher: American Association for Cancer Research (AACR)
    Publication Date: 2013
    detail.hit.zdb_id: 2036785-5
    detail.hit.zdb_id: 1432-1
    detail.hit.zdb_id: 410466-3
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