IMBDX

Our Solution

Early detection of cancer.

Presentations

게시물 목록
NO YEAR SUBJECT JOURNAL NAME LINK
6 2024

Multi-feature cell free DNA analysis and ensemble machine learning for early detection of cancer

Background Early cancer detection is crucial for reducing mortality rates, but current screening methods vary widely in age, intervals, and invasiveness. Unfortunately, over 50% of cancer deaths occur in types without recommended screening tests. Non-invasive multi-cancer early detection (MCED) technology could provide a solution.   Methods We enrolled both healthy individuals (398) and patients diagnosed with stage I-IV colon (107), liver (113), lung (213), prostate cancer (92), gastric (100), pancreatic (113), breast (74), and ovarian (87) cancers for the development of the Multi-Cancer Early Detection (MCED) test. Whole-genome methylation sequencing was performed on tumor and normal tissues at 15X coverage for marker selection, while cell-free DNA was sequenced at 30X coverage to construct the machine learning model. We calculated three genome-wide features: methylation, copy number variation, and fragment-based patterns. For the training set, which comprised 60% of the samples, support vector machine (SVM) algorithms were applied to these features, and ensemble logistic regression was employed to identify cancer signals and tissue-of-origin (TOO) based on scores fr|om the single-feature models. To determine the minimum yield that maintains equivalent performance, we downsampled a 50% fraction of reads fr|om each cfDNA sequencing dataset.   Results The overall sensitivity of the cancer detection model was 85.7% at the specificity of 95.6%, and TOO accuracy was 81.1%. The sensitivity performance for cancers without recommended screening tests previously, such as pancreatic (83.9%) and ovarian (79.7%) cancer, has also been maintained at a high sensitivity level. In-silico analysis confirmed that reducing coverage to 15X, half of the original, maintains high performance in sensitivity and specificity, significantly lowering data processing requirements. Conclusions Proposed MCED method for eight types of cancer, including pancreatic, and ovarian cancer, which were previously difficult to diagnose early, performs with high sensitivity. The reduced coverage of 15X can lower sequencing costs and increase patient accessibility.  

Multi-feature cell free DNA analysis and ensemble machine learning for early detection of cancer

ESMO

LINK _VIEW
5 2024

ctDNA as a biomarker in phase II study of tepotinib in advanced solid cancers with MET exon 14 skipping mutation or amplification (KCSG AL19-17).

Abstract Background Tepotinib consistently demonstrated antitumor activity in patients with MET exon 14 skipping mutation (METex14) and promising activity in various cancers with MET amplification, according to previous reports. We assessed plasma ctDNA as a potential biomarker in MET-dysregulated advanced cancer patients with tepotinib treatment.    Methods KM-08 (KCSG AL19-17, NCT04647838) was a phase 2, multicenter study with tepotinib treatment for patients with advanced or metastatic solid cancers harboring either METex14 or MET amplification detected in tissue-based next-generation sequencing (NGS). For exploratory analyses, we analyzed the genetic profile using liquid-based NGS testing with AlphaLiquid-100 panel (IMBdx Inc. Seoul, KR) at baseline (T0), after six weeks during treatment (T1), and at the time of disease progression (T2).    Results Baseline ctDNA NGS data was available in 28 (80%) out of 35 patients enrolled in the trial. Among them, METex14 or MET amplification was detected in 18 patients, with a sensitivity of 64.3%. The most commonly co-mutated gene was TP53, followed by PIK3CA, ATM, MYCN, and KRAS. The objective response rate (ORR) in plasma MET positive (PM+) patients was higher (81.2%) than the ORR in plasma MET negative (PM−) patients’ group (30.0%). In contrast, PM− group had a longer progression-free survival (PFS) and overall survival (OS) than PM+ group. PFS was 11.0 months (95% CI 8.1, 13.9) vs 6.0 months (95% CI 3.6, 8.3) and OS was NR vs 14.0 months (95% CI 4.7, 23.3), respectively. The molecular responder (MR, MET alteration variant allele frequency [VAF] T1/T0 <50%) was 80.0% (12/15 patients), and the molecular non-responder (MNR, METVAF T1/T0≥50%) was 20.0% (3/15 patients). ORR was higher in the MR group (91.7%) than in the MNR group (33.3%). PFS and OS were longer in the MR group than in the MNR group, 6.0 months (95% CI 0.0, 14.5) vs 3.0 months (95% CI 1.4, 4.6) with P= 0.114 and NR vs 4.0 months (95% CI 2.4, 5.6) with P= 0.067, respectively. Out of the 20 patients with samples available at T2, one had an on-target mutation on MET (D1228N, and Y1230H) while two had off-target emerging oncogenic alterations in KRAS, BRAF, and ERBB2 genes.    Conclusions In the liquid biomarker analysis in the MET-dysregulated cancer patients who were treated with tepotinib, the presence of ctDNA METalteration at baseline was associated with a higher response rate but shorter PFS and OS. The molecular response was well correlated with the radiological response and associated with better outcomes. (Funded by Merck KGaA, Darmstadt, Germany, ClinicalTrials.gov number, NCT04647838.)

ctDNA as a biomarker in phase II study of tepotinib in advanced solid cancers with MET exon 14 skipping mutation or amplification (KCSG AL19-17).

ASCO

LINK _VIEW
4 2024

Pairwise analysis of plasma cell-free DNA before and after paclitaxel plus ramucirumab treatment in patients with metastatic gastric cancer

Abstract Background Plasma cell-free DNA (cfDNA) analysis has emerged as an appealing alternative to detect somatic mutations. This study compared cfDNA at baseline (baseline-cfDNA) and progressive disease (PD-cfDNA) and tumor tissue DNA (ttDNA) in patients with metastatic gastric cancer who underwent palliative second-line paclitaxel+ramucirumab treatment.   Methods We conducted targeted sequencing of 106 cancer-related genes using germline DNA, baseline-cfDNA, and PD-cfDNA samples. The results were then compared with conventional cancer panel results using ttDNA.   Results Of 76 consecutively enrolled patients who received paclitaxel+ramucirumab treatment, 46 patients (27 males; median age 57.5 [range, 32-73] years) with access to all three samples were analyzed along with their ttDNA data. A total of 138, 145, and 80 mutations were detected in baseline-cfDNA, PD-cfDNA, and ttDNA respectively. Combined analysis of baseline-cfDNA and ttDNA revealed that TP53 (56.5%) was the most frequently mutated gene, followed by CDH1 (26.1%), KRAS (21.7%), and APC (13.5%). For the top four genes, the sensitivity and positive predictive value of baseline-cfDNA compared with ttDNA were 71.8% and 51.9%, respectively. Compared with ttDNA alone, 32 patients (70.0%) benefited fr|om baseline-cfDNA in detecting novel mutations. When combined with baseline-cfDNA and PD-cfDNA, novel mutations were discovered in 34 patients (73.9%). Of note, PD-cfDNA analysis detected 9 novel pathogenic mutations in TP53, APC, PIK3CA, CDH1, RNF43, CTNNB1, and BRCA2 genes in 8 patients (17.4%) after treatment. In baseline-cfDNA, patients with a circulating ttDNA fraction concentration at 110-160 bp of >4.3777 ng/µL had significantly shorter progression-free survival (PFS) (median 3.5 vs. 5.3 months, P=0.016). In addition, maximal variant allele frequency (VAF) values of >0.1045 (median 3.4 vs. 5.2 months, P=0.022) and the sum of VAF values of >0.2071 (median 3.4 vs. 5.2 months, P=0.028) were significantly associated with shorter PFS. In patients with TP53 mutations, those with TP53 VAF values of >0.1014 significantly had worse PFS (median 4.6 vs. 6.4 months, P=0.022).   Conclusions Although cfDNA could not entirely take over the role of ttDNA, cfDNA analysis identified additional somatic mutations that were otherwise missed by ttDNA alone. Moreover, PD-cfDNA analysis detected novel pathogenic mutations that developed during treatment, implicating the clonal evolution of cancer. In addition, baseline cfDNA predicted PFS of patients receiving paclitaxel+ramucirumab therapy.

Pairwise analysis of plasma cell-free DNA before and after paclitaxel plus ramucirumab treatment in patients with metastatic gastric cancer

AACR

LINK _VIEW
3 2024

Assessing the clinical value of ctDNA sequencing for initial tumor profiling in metastatic colorectal cancer patients with sufficient tumor tissue

Abstract Introduction Tumor profiling including RAS, BRAF, HER2, and MSI/MMR status, is required to determine the treatment for patients with metastatic colorectal cancer (mCRC) at the time of diagnosis. While comprehensive tumor profiling using tissue-based next-generation sequencing (NGS) is increasingly adopted for initial profiling in mCRC, the role of circulating tumor DNA (ctDNA) NGS as initial testing in patients with sufficient tumor tissue is not clearly understood. We assessed the clinical value of ctDNA sequencing compared to tumor NGS in patients with newly diagnosed mCRC who have sufficient tumor specimens.   Methods We prospectively enrolled consecutive patients with newly diagnosed mCRC at the National Cancer Center Korea. As per the institutional protocol for mCRC, initial tumor profiling was performed on primary tumor tissue using an in-house NGS panel (NCC PCP ver.3), which included 525 genes. For ctDNA sequencing, patients were evaluated using the AlphaLiquid®100 comprehensive cancer panel (IMBdx, Inc.), which included 118 genes, before the initiation of chemotherapy. Additionally, immunohistochemical (IHC) testing for HER2 and polymerase chain reaction (PCR)/IHC testing for MSI and/or MMR were performed to assess the accuracy of HER2 and MSI/MMR status.   Results A total of 188 patients were enrolled. In 139 eligible patients, 275 potentially actionable mutations were found in 12 selected CRC-related genes (APC, TP53, KRAS, NRAS, BRAF, FBXW7, PIK3CA, ERBB2, SMAD4, NF1, EGFR, MET). Of these, 32% were found both in ctDNA and tissue; 54% were found in ctDNA only; 12% in tissue only, and 2% were discordant. For RAS/BRAF mutations, which are required for anti-EGFR treatment decisions, the concordance rate between ctDNA and tissue NGS was 83.1%, and the concordance was higher in patients with higher ctDNA concentrations. For 9 patients with potentially actionable copy number variations (CNV) in EGFR, HER2, MET, and FGFR1, 3 cases were found by both assays; 4 were found by ctDNA only, and 2 were found by tissue only. ctDNA NGS correctly predicted MSI/MMR status in 2 out of 4 patients with MSI-H/dMMR; in the 2 other patients, the MSI and MMR statuses were different, suggesting potential false positivity. In addition, the fold changes in ctDNA dynamics during treatment significantly correlated with changes in tumor size and CEA levels, as well as with droplet digital PCR copy number fold changes. In a patient with MET amplification, ctDNA NGS identified MET Y1230H as a potential acquired resistance mutation after crizotinib treatment, which responded to cabozantinib but not to capmatinib.   Conclusions Initial tumor profiling using ctDNA NGS yielded outcomes comparable to those of tumor tissue NGS in guiding treatment for patients with newly diagnosed mCRC, thereby suggesting its utility as an initial profiling method in mCRC.

Assessing the clinical value of ctDNA sequencing for initial tumor profiling in metastatic colorectal cancer patients with sufficient tumor tissue

AACR

LINK _VIEW
2 2023

Personalized circulating tumor DNA assay precisely predicts the response of neoadjuvant chemotherapy in breast cancer patients

Abstract Introduction  Circulating tumor DNA (ctDNA), which is detected in the blood as cell free DNA fragment fr|om tumor cells, could indicates genomic landscape, tumor burden and treatment response during chemotherapy as a non-invasive method. Especially, personized ctDNA assay by next-generation sequencing(NGS) is able to detect a trace amount of ctDNA and precisely figure out the change of the amount of ctDNA during NAC and follow up period after curative surgery. Here, we performed serial ctDNA evaluations in EBC patients who diagnosed as TNBC or HER2-positive BC and received NAC followed by curative surgery. We aimed to predict NAC response and detect minimal residual disease (MRD) using personalized ctDNA assay.    Methods  CtDNA was detected by AlphaLiquid®Detect, a tumor-informed personalized MRD detection assay exploring most of the mutations in tumor. Whole exome sequencing (WES) of tumor tissue and peripheral blood mononuclear cells (PBMCs) was performed. Patient-specific somatic mutations were selected using a proprietary algorithm. In brief, clonal variants were prioritized using integrated information including variant allele frequency, population allele frequency databases, somatic variant databases, variant pathogenicity, and genomic context. Up to 100 variants were selected for patient monitoring. A hybridization capture panel consisting of a pool of 4 patients’ selected variants was synthesized. These bespoke panels (BSPs) were used for ctDNA detection. Patients with more than 2 tumor-derived mutations detected in plasma were considered as ctDNA positive. Inclusion criteria included patient who diagnosed as stage IIA-IIIC BC planned to NAC followed by curative surgery. Among BC subtypes, TNBC and HER2-positive BC were allowed. Collection of specimens and associated clinical data used in this study was approved by the Institutional Review Board of Samsung Medical Center (IRB File No.2021-02-033), and we received informed consents for this study.    Results  fr|om May 2021 to Sep 2022, 158 patients has been enrolled. Archival tissues were not available in 47 patients and tissue WES had failed in six patients. Therefore, 105 patients were enrolled and analyzed their ctDNA at diagnosis based on tissue WES data. Of 105 patients, Median age of BC patients was 49.3 years of age (range: 26.1, 67.8). Thirty-six patients (34.3%) were post-menopausal status and others (65.7%) were pre-menopausal status. In BC pathology at diagnosis, 56 (53.3%) were TNBC and other 49 (46.7%) were HER2-positive BC. Among HER2-positive BC, hormone receptor (HR)-positive were in 21 (20.0%). In clinical stage at diagnosis, stage II were 46 (43.8%) and stage III in 59 (56.2%). In 105 patients, median number of somatic mutations was 60 (interquartile range [IQR]: 38.5, 91). CtDNA detection rate at BC diagnosis was 90.5% and all of BC which not be detected ctDNA was HER2-positive BC with clinical stage II. Median amount of ctDNA at diagnosis was 20 (IQR: 6, 44). In the number of somatic mutations, there was no difference according to BC subtypes (P=0.121) and clinical stage (P=0.700) but the amounts of ctDNA at diagnosis was different. CtDNA was much more detected in TNBC compared to HER2-positive BC (Median: 34.5 vs. 15.9; P< 0.001) and clinical stage III compared to clinical stage II (Median 33.2 vs. 19.5; P=0.002). After NAC, ctDNA at curative surgery was tested in 70 patients. In 70 patients, pathologic complete response(pCR) was observed in 44 patients. CtDNA was detected in ten patients (14.3%) and eight did not achieve pCR and two with pCR (Specificity of assay: 95.5%, positive predictive value: 0.80, P=0.032).    Conclusions  Personalized ctDNA assay can precisely detected ctDNA at diagnosis and their detection rate was associated with BC subtypes and clinical stage. In addition, ctDNA at curative surgery also can predict NAC response in EBC patients. Long term ctDNA follow up of MRD would be warranted.

Personalized circulating tumor DNA assay precisely predicts the response of neoadjuvant chemotherapy in breast cancer patients

SABCS

LINK _VIEW