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49
result(s) for
"Oxnard, Geoffrey R."
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The cellular origins of drug resistance in cancer
2016
Two new studies show that mechanisms of acquired resistance to targeted therapy in lung cancer do not necessarily pre-exist in resistant subclones. Instead, some cancers may harbor the potential to acquire a variety of drug-resistance mechanisms after response to targeted therapy.
Journal Article
Circulating tumor DNA in advanced solid tumors: Clinical relevance and future directions
by
Parsons, Heather A
,
Cheng, Michael L
,
Hanna, Glenn J
in
Clinical decision making
,
Decision making
,
Deoxyribonucleic acid
2021
The application of genomic profiling assays using plasma circulating tumor DNA (ctDNA) is rapidly evolving in the management of patients with advanced solid tumors. Diverse plasma ctDNA technologies in both commercial and academic laboratories are in routine or emerging use. The increasing integration of such testing to inform treatment decision making by oncology clinicians has complexities and challenges but holds significant potential to substantially improve patient outcomes. In this review, the authors discuss the current role of plasma ctDNA assays in oncology care and provide an overview of ongoing research that may inform real‐world clinical applications in the near future.
Journal Article
Defining a Radiomic Response Phenotype: A Pilot Study using targeted therapy in NSCLC
by
Aerts, Hugo J. W. L.
,
Rizvi, Naiyer
,
Zhao, Binsheng
in
692/4028/67/1059/602
,
692/4028/67/2321
,
Algorithms
2016
Medical imaging plays a fundamental role in oncology and drug development, by providing a non-invasive method to visualize tumor phenotype. Radiomics can quantify this phenotype comprehensively by applying image-characterization algorithms, and may provide important information beyond tumor size or burden. In this study, we investigated if radiomics can identify a gefitinib response-phenotype, studying high-resolution computed-tomography (CT) imaging of forty-seven patients with early-stage non-small cell lung cancer before and after three weeks of therapy. On the baseline-scan, radiomic-feature Laws-Energy was significantly predictive for EGFR-mutation status (AUC = 0.67,
p
= 0.03), while volume (AUC = 0.59,
p
= 0.27) and diameter (AUC = 0.56,
p
= 0.46) were not. Although no features were predictive on the post-treatment scan (
p
> 0.08), the change in features between the two scans was strongly predictive (significant feature AUC-range = 0.74–0.91). A technical validation revealed that the associated features were also highly stable for test-retest (mean ± std: ICC = 0.96 ± 0.06). This pilot study shows that radiomic data before treatment is able to predict mutation status and associated gefitinib response non-invasively, demonstrating the potential of radiomics-based phenotyping to improve the stratification and response assessment between tyrosine kinase inhibitors (TKIs) sensitive and resistant patient populations.
Journal Article
Acquired EGFR C797S mutation mediates resistance to AZD9291 in non–small cell lung cancer harboring EGFR T790M
2015
A mutation conferring resistance to novel irreversible EGFR inhibitors is identified in cell-free plasma DNA from lung cancer patients.
Here we studied cell-free plasma DNA (cfDNA) collected from subjects with advanced lung cancer whose tumors had developed resistance to the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI) AZD9291. We first performed next-generation sequencing of cfDNA from seven subjects and detected an acquired
EGFR
C797S mutation in one; expression of this mutant
EGFR
construct in a cell line rendered it resistant to AZD9291. We then performed droplet digital PCR on serial cfDNA specimens collected from 15 AZD9291-treated subjects. All were positive for the T790M mutation before treatment, but upon developing AZD9291 resistance three molecular subtypes emerged: six cases acquired the C797S mutation, five cases maintained the T790M mutation but did not acquire the C797S mutation and four cases lost the T790M mutation despite the presence of the underlying
EGFR
activating mutation. Our findings provide insight into the diversity of mechanisms through which tumors acquire resistance to AZD9291 and highlight the need for therapies that are able to overcome resistance mediated by the
EGFR
C797S mutation.
Journal Article
Strategies for the successful implementation of plasma-based NSCLC genotyping in clinical practice
by
Gray, Jhanelle E
,
Aggarwal Charu
,
Rolfo, Christian D
in
Biopsy
,
Clinical decision making
,
Clinical medicine
2021
Upfront tumour genotyping is now considered an essential step in guiding treatment decision-making in the management of patients with advanced-stage non-small-cell lung cancer (NSCLC) in light of the ever-expanding toolbox of targeted therapies and immune-checkpoint inhibitors. However, genotyping of tumour biopsy samples is not feasible for all patients and, therefore, genomic analysis of circulating tumour DNA (ctDNA) has emerged as a compelling non-invasive option. Current guidelines universally recommend genotyping and support the use of ctDNA testing in certain settings, although they often omit the detail necessary for integrating these tests into clinical care on an individual basis. In this Perspective, we describe the rationale, promise and challenges associated with ctDNA-based NSCLC genotyping and suggest a framework for the implementation of these assays into routine clinical practice. We also offer considerations for the interpretation of ctDNA genotyping results, which, particularly when using next-generation sequencing panels, can be nuanced. Through the addition of this new approach to clinical practice, we propose that oncologists might finally be able to utilize effective genotyping in nearly all patients with advanced-stage NSCLC.Genotyping is recommended for all patients with metastatic non-squamous non-small-cell lung cancers (NSCLC), both to enable patients to receive targeted therapies and to avoid therapies they are unlikely to benefit from. However, obtaining tumour biopsy material for genotyping is often challenging and is unfeasible in some patients, indicating the need to incorporate liquid biopsy approaches. In this Perspective, the authors provide guidance on how analysis of ctDNA from liquid biopsy samples in patients with metastatic NSCLC prior to first-line therapy has the potential to extend the benefits of genotyping to virtually all patients.
Journal Article
Tissue and liquid biopsy profiling reveal convergent tumor evolution and therapy evasion in breast cancer
2022
Pathological and genomic profiling have transformed breast cancer care by matching patients to targeted treatments. However, tumors evolve and evade therapeutic interventions often through the acquisition of genomic mutations. Here we examine patients profiled with tissue (TBx) and liquid biopsy (LBx) as part of routine clinical care, to characterize the tumor evolutionary landscape and identify potential vulnerabilities in the relapsed setting. Real-world evidence demonstrates that LBx is utilized later in care and identifies associations with intervening therapy. While driver events are frequently shared, acquired LBx alterations are detected in a majority of patients, with the highest frequency in ER+ disease and in patients with longer biopsy intervals. Acquired mutations are often polyclonal and present at lower allelic fractions, suggesting multi-clonal convergent evolution. In addition to well-characterized resistance mutations (e.g.,
ESR1
,
NF1
,
RB1
,
ERBB2)
, we observe a diversity of rarer but potentially targetable mutations (e.g.,
PIK3CA, HRAS
/
NRAS
/
KRAS
,
FGFR1/2/3
,
BRAF
) and fusions (e.g.,
FGFR1/2
,
ERBB2
,
RET
), as well as
BRCA1/2
reversions through a variety of mechanisms, including splice alterations and structural deletions. This study provides insights on treatment and selection-driven tumor evolution and identifies potential combinatorial treatment options in advanced breast cancer.
Liquid biopsies could be valuable tools to monitor breast cancer progression and evolution. Here, the authors investigate genomic profiling of tissue and liquid biopsies in a large cohort of patients with breast cancer during the course of therapy to characterise tumour evolution and acquired mutations.
Journal Article
Comprehensive pan-cancer genomic landscape of KRAS altered cancers and real-world outcomes in solid tumors
by
Schutzman, Jennifer L.
,
Hegde, Priti S.
,
Schrock, Alexa B.
in
631/67/69
,
692/308/409
,
692/4017
2022
Recent clinical development of KRAS inhibitors has heightened interest in the genomic landscape of
KRAS
-altered cancers. We performed a pan-cancer analysis of
KRAS
-altered samples from 426,706 adult patients with solid or hematologic malignancies using comprehensive genomic profiling; additional analyses included 62,369 liquid biopsy and 7241 pediatric samples. 23% of adult pan-cancer samples had
KRAS
alterations; 88% were mutations, most commonly
G12D/G12V/G12C/G13D/G12R
, and prevalence was similar in liquid biopsies. Co-alteration landscapes were largely similar across
KRAS
mutations but distinct from
KRAS
wild-type, though differences were observed in some tumor types for tumor mutational burden, PD-L1 expression, microsatellite instability, and other mutational signatures. Prognosis of
KRAS-
mutant versus other genomic cohorts of lung, pancreatic, and colorectal cancer were assessed using a real-world clinicogenomic database. As specific KRAS inhibitors and combination therapeutic strategies are being developed, genomic profiling to understand co-alterations and other biomarkers that may modulate response to targeted or immunotherapies will be imperative.
Journal Article
Detection of EGFR mutations in non-small cell lung cancer by droplet digital PCR
by
Williamson, Drew F. K.
,
Sholl, Lynette M.
,
Rojas-Rudilla, Vanesa
in
Alleles
,
Assaying
,
Cancer
2022
Activating mutations in EGFR predict benefit from tyrosine kinase inhibitor therapy for patients with advanced non-small cell lung cancer. Directing patients to appropriate therapy depends on accurate and timely EGFR assessment in the molecular pathology laboratory. This article describes the analytical design, performance characteristics, and clinical implementation of an assay for the rapid detection of EGFR L858R and exon 19 deletion mutations. A droplet digital polymerase chain reaction (ddPCR) assay was implemented with probe hydrolysis-dependent signal detection. A mutation-specific probe was used to detect EGFR L858R. A loss of signal design was used to detect EGFR exon 19 deletion mutations. Analytical sensitivity was dependent on DNA input and was as low as 0.01% variant allele fraction for the EGFR L858R assay and 0.1% variant allele fraction for the EGFR exon 19 deletion assay. Correlation of 20 clinical specimens tested by ddPCR and next generation sequencing showed 100% concordance. ddPCR showed 53% clinical sensitivity in the detection of EGFR mutations in plasma cell-free DNA from patients with lung cancer. The median clinical turnaround time was 5 days for ddPCR compared to 13 days for next generation sequencing. The findings show that ddPCR is an accurate and rapid method for detecting EGFR mutations in patients with non-small cell lung cancer.
Journal Article
Pan-tumor activity of olomorasib, a next-generation KRAS G12C inhibitor in KRAS G12C-mutant advanced solid tumors: a first-in-human study
by
Burns, Timothy F.
,
Willard, Melinda D.
,
Oxnard, Geoffrey R.
in
631/154/152
,
631/67/1059
,
692/4028/67/1059
2026
This multicenter, first-in-human Phase 1 study (NCT04956640) evaluated olomorasib (LY3537982), a next-generation KRAS G12C inhibitor designed to enhance target occupancy at low absolute exposures. In total, data from 195 patients are reported: Phase 1a dose escalation (
n
= 112) assessed olomorasib monotherapy at 50, 100, 150 or 200 mg BID across
KRAS
G12C-mutant advanced solid tumors; the primary objective was to determine the recommended Phase 2 dose (RP2D) based on dose-limiting toxicities (DLTs). No DLTs occurred, and 150 mg BID was selected as the RP2D. The primary objective for the Phase 1b dose expansion (
n
= 83) was to evaluate the safety and tolerability of olomorasib in specific
KRAS
G12C-mutant tumor types. Olomorasib was well tolerated, with predominantly grade 1–2 treatment-related adverse events (TRAEs) and infrequent grade 3 TRAEs; no grade 4/5 TRAEs occurred. Secondary objectives evaluated the antitumor activity of olomorasib. Among 168 efficacy-evaluable patients, the ORR and median PFS were both higher in non-CRC solid tumors compared to CRC, including in patients with NSCLC who previously received a KRAS G12C inhibitor. Intracranial responses were observed in patients with untreated, active brain metastases. This may support the potential of next-generation KRAS G12C inhibitors to overcome limitations of earlier agents and justify further investigation of combination therapy.
KRAS G12C inhibitors have improved outcomes but mainly in non-small cell lung cancer and colorectal cancer, despite it being a well-established oncogene in a range of cancer types. Here, the authors present a first-in-human phase I/II clinical trial investigating the next-generation KRAS G12C inhibitor, olomorasib, in KRAS G12C-mutant advanced solid tumors.
Journal Article
Real-World Clinical Performance of a DNA-Based Comprehensive Genomic Profiling Assay for Detecting Targetable Fusions in Nonsquamous NSCLC
by
Li, Gerald
,
Trabucco, Sally E
,
Tolba, Khaled
in
Aged
,
Cancer
,
Cancer Diagnostics and Molecular Pathology
2024
Abstract
Background
Genomic fusions are potent oncogenic drivers across cancer types and many are targetable. We demonstrate the clinical performance of DNA-based comprehensive genomic profiling (CGP) for detecting targetable fusions.
Materials and Methods
We analyzed targetable fusion genes in >450 000 tissue specimens profiled using DNA CGP (FoundationOne CDx, FoundationOne). Using a de-identified nationwide (US-based) non–small cell lung cancer (NSCLC) clinico-genomic database, we assessed outcomes in patients with nonsquamous NSCLC (NonSqNSCLC) who received matched therapy based on a fusion identified using DNA CGP. Lastly, we modeled the added value of RNA CGP for fusion detection in NonSqNSCLC.
Results
We observed a broad diversity of fusion partners detected with DNA CGP in conjunction with targetable fusion genes (ALK, BRAF, FGFR2, FGFR3, NTRK1/2/3, RET, and ROS1). In NonSqNSCLC with oncogenic ALK, NTRK, RET, and ROS1 fusions detected by DNA CGP, patients treated with a matched tyrosine kinase inhibitor had better real-world progression-free survival than those receiving alternative treatment regimens and benefit was observed regardless of the results of orthogonal fusion testing. An estimated 1.3% of patients with NonSqNSCLC were predicted to have an oncogenic driver fusion identified by RNA, but not DNA CGP, according to a model that accounts for multiple real-world factors.
Conclusion
A well-designed DNA CGP assay is capable of robust fusion detection and these fusion calls are reliable for informing clinical decision-making. While DNA CGP detects most driver fusions, the clinical impact of fusion detection is substantial for individual patients and exhaustive efforts, inclusive of additional RNA-based testing, should be considered when an oncogenic driver is not clearly identified.
Genomic fusions are potent oncogenic drivers across cancer types, and many are targetable. This study demonstrated the clinical performance of a well-designed DNA-based comprehensive genomic profiling assay for detecting targetable fusions.
Journal Article