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Purpose: BRAF V600E mutations are rarely associated with objective responses to the BRAF inhibitor vemurafenib in patients with metastatic colorectal cancer (CRC). Blockade of BRAF V600E by vemurafenib causes feedback upregulation of EGFR, whose signaling activities can be impeded by cetuximab., Methods: One hundred six patients with BRAF V600E -mutated metastatic CRC previously treated with one or two regimens were randomly assigned to irinotecan and cetuximab with or without vemurafenib (960 mg PO twice daily)., Results: Progression-free survival, the primary end point, was improved with the addition of vemurafenib (hazard ratio, 0.50, P = .001). The response rate was 17% versus 4% ( P = .05), with a disease control rate of 65% versus 21% ( P < .001). A decline in circulating tumor DNA BRAF V600E variant allele frequency was seen in 87% versus 0% of patients ( P < .001), with a low incidence of acquired RAS alterations at the time of progression. RNA profiling suggested that treatment benefit did not depend on previously established BRAF subgroups or the consensus molecular subtype., Conclusion: Simultaneous inhibition of EGFR and BRAF combined with irinotecan is effective in BRAF V600E -mutated CRC.

Purpose: Plasma genotyping may identify mutations in potentially "actionable" cancer genes, such as BRCA1/2 , but their clinical significance is not well-defined. We evaluated the characteristics of somatically acquired BRCA1/2 mutations in patients with metastatic breast cancer (MBC)., Experimental Design: Patients with MBC undergoing routine cell-free DNA (cfDNA) next-generation sequencing (73-gene panel) before starting a new therapy were included. Somatic BRCA1/2 mutations were classified as known germline pathogenic mutations or novel variants, and linked to clinicopathologic characteristics. The effect of the PARP inhibitor, olaparib, was assessed in vitro , using cultured circulating tumor cells (CTCs) from a patient with a somatically acquired BRCA1 mutation and a second patient with an acquired BRCA2 mutation., Results: Among 215 patients with MBC, 29 (13.5%) had somatic cfDNA BRCA1/2 mutations [nine (4%) known germline pathogenic and rest (9%) novel variants]. Known germline pathogenic BRCA1/2 mutations were common in younger patients ( P = 0.008), those with triple-negative disease ( P = 0.022), and they were more likely to be protein-truncating alterations and be associated with TP53 mutations. Functional analysis of a CTC culture harboring a somatic BRCA1 mutation demonstrated high sensitivity to PARP inhibition, while another CTC culture harboring a somatic BRCA2 mutation showed no differential sensitivity. Across the entire cohort, APOBEC mutational signatures (COSMIC Signatures 2 and 13) and the "BRCA" mutational signature (COSMIC Signature 3) were present in BRCA1/2- mutant and wild-type cases, demonstrating the high mutational burden associated with advanced MBC., Conclusions: Somatic BRCA1/2 mutations are readily detectable in MBC by cfDNA analysis, and may be present as both known germline pathogenic and novel variants., (©2020 American Association for Cancer Research.)

Purpose: Recent advances in molecular diagnostic technologies have allowed for the evaluation of solid tumor malignancies via noninvasive blood sampling, including circulating tumor DNA (ctDNA) profiling. We sought to characterize the ctDNA genomic alteration landscape in patients with biliary tract cancers (BTCs)., Patients and Methods: From January 2015 to February 2018, 124 patients with BTC at the Mayo Clinic Comprehensive Cancer Center underwent ctDNA testing using a clinically available assay. The majority of samples (n = 122) were tested using the 73-gene panel that includes somatic genomic targets, including complete or critical exon coverage in 30 and 40 genes, respectively, and in some, amplifications, fusions, and indels., Results: A total of 138 samples were included, with approximately 70% of patients having intrahepatic BTC. All patients had locally advanced or metastatic BTC. Samples with one or more alterations, when variants of unknown significance were excluded, numbered 105 (76%). Each sample contained, on average, three alterations with a median allelic fraction of 0.52%. The overall landscape of alterations is summarized in Figures 1 and 2. After excluding variants of unknown significance, therapeutically relevant alterations were observed in 76 patients (55%), including BRAF mutations, ERBB2 amplifications, FGFR2 fusions, FGFR2 mutations, and IDH1 mutations seen in 21% of patients. A different spectrum of alterations was observed in patients with early-onset BTC (younger than age 50 years) compared with older patients (older than age 50 years)., Conclusion: Data on ctDNA in BTC is currently limited. Our study, the largest cohort reported to date to our knowledge, demonstrates the feasibility of ctDNA testing in this disease. We provide a foundation upon which the field can continue to grow.

Purpose: Gene fusions are established oncogenic drivers and emerging therapeutic targets in advanced colorectal cancer. This study aimed to detail the frequencies and clinicopathological features of gene fusions in colorectal cancer using a circulating tumor DNA assay., Methods: Circulating tumor DNA samples in patients with advanced colorectal cancer were analyzed at 4,581 unique time points using a validated plasma-based multigene assay that includes assessment of fusions in FGFR2 , FGFR3 , RET , ALK , NTRK1 , and ROS1. Associations between fusions and clinicopathological features were measured using Fisher's exact test. Relative frequencies of genomic alterations were compared between fusion-present and fusion-absent cases using an unpaired t test., Results: Forty-four unique fusions were identified in 40 (1.1%) of the 3,808 patients with circulating tumor DNA detected: RET (n = 6; 36% of all fusions detected), FGFR3 (n = 2; 27%), ALK (n = 10, 23%), NTRK1 (n = 3; 7%), ROS1 (n = 2; 5%), and FGFR2 (n = 1; 2%). Relative to nonfusion variants detected, fusions were more likely to be subclonal (odds ratio, 8.2; 95% CI, 2.94 to 23.00; P < .001). Mutations associated with a previously reported anti-epidermal growth factor receptor (anti-EGFR) therapy resistance signature (subclonal RAS and EGFR mutations) were found with fusions in FGFR3 (10 of 12 patients), RET (nine of 16 patients), and ALK (seven of 10 patients). For the 27 patients with available clinical histories, 21 (78%) had EGFR monoclonal antibody treatment before fusion detection., Conclusion: Diverse and potentially actionable fusions can be detected using a circulating tumor DNA assay in patients with advanced colorectal cancer. Distribution of coexisting subclonal mutations in EGFR , KRAS , and NRAS in a subset of the patients with fusion-present colorectal cancer suggests that these fusions may arise as a novel mechanism of resistance to anti-EGFR therapies in patients with metastatic colorectal cancer., Competing Interests: The following represents disclosure information provided by authors of this manuscript. All relationships are considered compensated unless otherwise noted. Relationships are self-held unless noted. I = Immediate Family Member, Inst = My Institution. Relationships may not relate to the subject matter of this manuscript. For more information about ASCO's conflict of interest policy, please refer to www.asco.org/rwc or ascopubs.org/po/author-center. Open Payments is a public database containing information reported by companies about payments made to US-licensed physicians (Open Payments). Katherine CliftonEmployment: WellCare (I) Stock and Other Ownership Interests: WellCare (I)Thereasa A. RichEmployment: Guardant Health Stock and Other Ownership Interests: Guardant Health, Myriad GeneticsVictoria M. RaymondEmployment: TrovaGene, Guardant Health Stock and Other Ownership Interests: TrovaGene, Guardant HealthArvind DasariConsulting or Advisory Role: Ipsen, AbbVie/Stemcentrx, Novartis, Voluntis, Lexicon Research Funding: Novartis, eFFECTOR Therapeutics, Eisai, Hutchison MediPharma, Merck, Guardant HealthJonathan M. LoreeConsulting or Advisory Role: Taiho Pharma Canada, Ipsen, Novartis, Bayer, AmgenTodd M. BauerEmployment: Tennessee Oncology Consulting or Advisory Role: Ignyta (Inst), Guardant Health, Loxo, Pfizer, Moderna Therapeutics (Inst), Pfizer (Inst), Exelixis Speakers' Bureau: Bayer Research Funding: Daiichi Sankyo (Inst), MedPacto (Inst), Incyte (Inst), Mirati Therapeutics (Inst), MedImmune (Inst), AbbVie (Inst), AstraZeneca (Inst), Leap Therapeutics (Inst), MabVax Therapeutics (Inst), Stemline Therapeutics (Inst), Merck (Inst), Eli Lilly (Inst), GlaxoSmithKline (Inst), Novartis (Inst), Pfizer (Inst), Genentech (Inst), Deciphera Pharmaceuticals (Inst), Merrimack (Inst), Immunogen (Inst), Millennium (Inst), Ignyta (Inst), Calithera Biosciences (Inst), Kolltan Pharmaceutical (Inst), Principia Biopharma (Inst), Peleton (Inst), Immunocore (Inst), Roche (Inst), Aileron Therapeutics (Inst), Bristol-Myers Squibb (Inst), Amgen (Inst), Moderna Therapeutics (Inst), Sanofi (Inst), Boehringer Ingelheim (Inst), Astellas Pharma (Inst), Five Prime Therapeutics (Inst), Jacobio Pharmaceuticals (Inst), Top Alliance BioSciences (Inst), Loxo (Inst), Janssen (Inst), Clovis Oncology (Inst), Takeda (Inst), Karyopharm Therapeutics (Inst), Onyx (Inst), Phosplatin Therapeutics (Inst), Foundation Medicine (Inst), ARMO BioSciences (Inst) Travel, Accommodations, Expenses: Astellas Pharma, AstraZeneca, Celgene, Clovis Oncology, EMD Serono, Genentech, Eli Lilly, Merck, Novartis, Pharmacyclics, SysmexYoung Kwang ChaeConsulting or Advisory Role: Foundation Medicine, Boehringer Ingelheim, Biodesix, Counsyl, AstraZeneca, Guardant Health, Takeda, Genentech, ImmuneOncia, Hanmi Speakers' Bureau: Genentech, Merck, AstraZeneca, Eli Lilly Research Funding: AbbVie, Bristol-Myers Squibb, Lexent Bio, Freenome, Biodesix Travel, Accommodations, Expenses: HanmiAxel GrotheyHonoraria: Elsevier, Aptitude Health, Imedex Consulting or Advisory Role: Genentech (Inst), Bayer (Inst), Bristol-Myers Squibb (Inst), Eli Lilly (Inst), Boston Biomedical (Inst), Amgen (Inst), Array BioPharma (Inst), Guardant Health (Inst), Daiichi Sankyo (Inst) Research Funding, Genentech (Inst), Bayer (Inst), Pfizer (Inst), Eisai (Inst), Eli Lilly (Inst), Boston Biomedical (Inst), Daiichi Sankyo (Inst), Array BioPharma (Inst) Travel, Accommodations, Expenses: Genentech, Bayer, Bristol-Myers Squibb, Boston Biomedical, Amgen, Boehringer Ingelheim, Merck Sharp & DohmeAndrew HendifarConsulting or Advisory Role: Novartis, Ipsen, Perthera, Celgene, AbbVie Research Funding: Ipsen Travel, Accommodations, Expenses: HalozymeDavid HenryHonoraria: Amgen, AMAG Pharmaceuticals Consulting or Advisory Role: AMAG Pharmaceuticals, Amgen Research Funding: Amgen Travel, Accommodations, Expenses: Amgen, AMAG PharmaceuticalsDaruka MahadevanHonoraria: Guardant Health, Caris Life Sciences Speakers' Bureau: Guardant Health, Caris Life Sciences Travel, Accommodations, Expenses: Guardant Health, Caris Life SciencesMohammad NezamiEmployment: Orange Coast Medical Center of Hope Stock and Other Ownership Interests: Sahel OncologyBenjamin TanConsulting or Advisory Role: Genentech Research Funding: Genentech, Eli Lilly, Pfizer, Bayer, Eisai, Exelixis, Merck Serono, Tyrogenex, SillaJen, Boehringer IngelheimZev A. WainbergConsulting or Advisory Role: Array BioPharma, Five Prime Therapeutics, Novartis, Eli Lilly, Merck, Merck KGaA, Bristol-Myers Squibb, Genentech, Bayer Research Funding: Novartis (Inst), Plexxikon (Inst), Pfizer (Inst), Merck (Inst), Five Prime Therapeutics (Inst) Travel, Accommodations, Expenses: GenentechRichard LanmanEmployment: Guardant Health, Veracyte Leadership: Guardant Health, Biolase Stock and Other Ownership Interests: Guardant Health, Biolase, Forward Medical Research Funding: Guardant HealthScott KopetzStock and Other Ownership Interests: MolecularMatch, Navire Consulting or Advisory Role: Roche, Genentech, EMD Serono, Merck, Karyopharm Therapeutics, Amal Therapeutics, Navire Pharma, Symphogen, Holy Stone, Biocartis, Amgen, Novartis, Eli Lilly, Boehringer Ingelheim, Boston Biomedical, AstraZeneca/MedImmune, Bayer Health, Pierre Fabre, EMD Serono Research Funding: Amgen (Inst), Sanofi (Inst), Biocartis (Inst), Guardant Health (Inst), Array BioPharma (Inst), Genentech (Inst), EMD Serono (Inst), MedImmune (Inst), Novartis (Inst), Eli Lilly (Inst)Van MorrisConsulting or Advisory Role: Clinical Genomics, Array Biopharma Research Funding: Bristol-Myers Squibb (Inst), Array BioPharma (Inst), EMD Serono (Inst) Travel, Accommodations, Expenses: Array BioPharma No other potential conflicts of interest were reported., (© 2019 by American Society of Clinical Oncology.)

Background: Colorectal cancer (CRC) has been shown to acquire RAS and EGFR ectodomain mutations as mechanisms of resistance to epidermal growth factor receptor (EGFR) inhibition (anti-EGFR). After anti-EGFR withdrawal, RAS and EGFR mutant clones lack a growth advantage relative to other clones and decay; however, the kinetics of decay remain unclear. We sought to determine the kinetics of acquired RAS/EGFR mutations after discontinuation of anti-EGFR therapy., Patients and Methods: We present the post-progression circulating tumor DNA (ctDNA) profiles of 135 patients with RAS/BRAF wild-type metastatic CRC treated with anti-EGFR who acquired RAS and/or EGFR mutations during therapy. Our validation cohort consisted of an external dataset of 73 patients with a ctDNA profile suggestive of prior anti-EGFR exposure and serial sampling. A separate retrospective cohort of 80 patients was used to evaluate overall response rate and progression free survival during re-challenge therapies., Results: Our analysis showed that RAS and EGFR relative mutant allele frequency decays exponentially (r2=0.93 for RAS; r2=0.94 for EGFR) with a cumulative half-life of 4.4 months. We validated our findings using an external dataset of 73 patients with a ctDNA profile suggestive of prior anti-EGFR exposure and serial sampling, confirming exponential decay with an estimated half-life of 4.3 months. A separate retrospective cohort of 80 patients showed that patients had a higher overall response rate during re-challenge therapies after increasing time intervals, as predicted by our model., Conclusion: These results provide scientific support for anti-EGFR re-challenge and guide the optimal timing of re-challenge initiation., (© The Author(s) 2018. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: Approximately 30% of tumor biopsies from patients with advanced-stage lung adenocarcinomas yield insufficient tissue for successful molecular subtyping. We have analyzed the clinical utility of next-generation sequencing (NGS) of cell-free circulating tumor DNA (ctDNA) in patients with inadequate tumor samples for tissue genotyping., Patients and Methods: We conducted the study in a multi-institutional prospective cohort of clinically unselected patients with advanced-stage lung adenocarcinomas with insufficient tissue for EGFR, ALK or ROS1 genotyping across 12 Spanish institutions (n = 93). ctDNA NGS was carried out by Guardant Health (Guardant360, Redwood City, CA), using a hybrid-capture-based 73-gene panel. Variants were deemed actionable if they were part of the OncoKB precision oncology knowledge database and classified in four levels of actionability based on their clinical or preclinical evidence for drug response., Results: Eighty-three out of 93 patients (89%) had detectable levels of ctDNA. Potentially actionable level 1-4 genomic alterations were detected in 53 cases (57%), of which 13 (14%) had level 1-2A alterations (Food and Drug Administration-approved and standard-care biomarkers according to lung cancer guidelines). Frequencies of each genomic alteration in ctDNA were consistent with those observed in unselected pulmonary adenocarcinomas. The majority of the patients (62%), particularly those with actionable alterations (87%), had more than one pathogenic variant in ctDNA. The median turnaround time to genomic results was 13 days. Twelve patients (13%) received genotype-matched therapies based on ctDNA results, deriving the expected clinical benefit. Patients with co-occurring pathogenic alterations had a significantly shorter median overall survival as compared with patients without co-occurring pathogenic alteration (multivariate hazard ratio = 5.35, P = 0.01)., Conclusion: Digital NGS of ctDNA in lung cancers with insufficient tumor samples for tissue sequencing detects actionable variants that frequently co-occur with other potentially clinically relevant genomic alterations, allowing timely initiation of genotype-matched therapies., (© The Author(s) 2018. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Background: To identify predictive markers for responders in lapatinib-treated patients and to demonstrate molecular changes during lapatinib treatment via cell-free genomics., Patients and Methods: We prospectively evaluated the efficacy of combining lapatinib with capecitabine and oxaliplatin as first line neoadjuvant therapy in patients with previously untreated, HER2-overexpressing advanced gastric cancer. A parallel biomarker study was conducted by simultaneously performing immunohistochemistry and next-generation sequencing (NGS) with tumor and blood samples., Results: Complete response was confirmed in 7/32 patients (21.8%), 2 of whom received radical surgery with pathologic-confirmed complete response. Fifteen partial responses (46.8%) were observed, resulting in a 68.6% overall response rate. NGS of the 16 tumor specimens demonstrated that the most common co-occurring copy number alteration was CCNE1 amplification, which was present in 40% of HER2+ tumors. The relationship between CCNE1 amplification and lack of response to HER2-targeted therapy trended toward statistical significance (66.7% of non-responders versus 22.2% of responders harbored CCNE1 amplification; P = 0.08). Patients with high level ERBB2 amplification by NGS were more likely to respond to therapy, compared with patients with low level ERBB2 amplification (P = 0.02). Analysis of cfDNA showed that detectable ERBB2 copy number amplification in plasma was predictive to the response (100%, response rate) and changes in plasma-detected genomic alterations were associated with lapatinib sensitivity and/or resistance. The follow-up cfDNA genomics at disease progression demonstrated that there are emergences of other genomic aberrations such as MYC, EGFR, FGFR2 and MET amplifications., Conclusions: The present study showed that HER2+ GC patients respond differently according to concomitant genomic aberrations beyond ERBB2, high ERBB2 amplification by NGS or cfDNA can be a positive predictor for patient selection, and tumor genomic alterations change significantly during targeted agent therapy.

Purpose: We describe herein a novel P447&#95;L455 deletion in the C2 domain of PIK3CA in a patient with an ER + breast cancer with an excellent response to the PI3Kα inhibitor alpelisib. Although PIK3CA deletions are relatively rare, a significant portion of deletions cluster within amino acids 446-460 of the C2 domain, suggesting these residues are critical for p110α function. Experimental Design: A computational structural model of PIK3CA delP447-L455 in complex with the p85 regulatory subunit and MCF10A cells expressing PIK3CA delP447-L455 and PIK3CA H450&#95;P458del were used to understand the phenotype of C2 domain deletions. Results: Computational modeling revealed specific favorable inter-residue contacts that would be lost as a result of the deletion, predicting a significant decrease in binding energy. Coimmunoprecipitation experiments showed reduced binding of the C2 deletion mutants with p85 compared with wild-type p110α. The MCF10A cells expressing PIK3CA C2 deletions exhibited growth factor-independent growth, an invasive phenotype, and higher phosphorylation of AKT, ERK, and S6 compared with parental MCF10A cells. All these changes were ablated by alpelisib treatment. Conclusions: C2 domain deletions in PIK3CA generate PI3K dependence and should be considered biomarkers of sensitivity to PI3K inhibitors. Clin Cancer Res; 24(6); 1426-35. ©2017 AACR ., (©2017 American Association for Cancer Research.)

Background: While deregulation of the cyclin D1-CDK4/6-retinoblastoma pathway is common in hormone receptor positive (HR+) breast cancer, Rb is usually intact in HR+ breast cancer, and targeted CDK 4/6 inhibitors that act upstream of Rb, are routinely being utilized in clinical practice. However, factors that can lead to clinical resistance to CDK 4/6 inhibitors are not known., Patients and Methods: We identified patients who had pre- and post-genotyping in tissue and peripheral blood samples after receiving CDK 4/6 inhibitors. Genotyping was carried out in tumor tissue or blood collected before start of CDK 4/6 inhibitor and after disease progression on CDK 4/6 inhibitor, covering more than 90% of the coding region in RB1., Results: We identified detectable acquired RB1 mutations in circulating tumor DNA (ctDNA) after exposure to CDK4/6 inhibitor (palbociclib, palbociclib, ribociclib) for 5, 8, and 13 months, respectively, in three patients. The RB1 mutations included substitution in donor splicing site of exon 8 of the RB1 gene in patient #1; substitution in donor splicing site of exon 22 of RB1 gene, exon 19 deletion, exon 3 insertion in patient #2; and RB1 exon 16 H483Y mutation in patient #3. None of these RB1 mutations were present in the pre-CDK 4/6 specimen highlighting these molecular alterations, which lead to functional loss of Rb1, likely emerged under selective pressure from the CDK4/6 inhibitor potentially confering therapeutic resistance., Conclusion: This is the first clinical report to describe the emergence of somatic RB1 mutations after exposure to palbociclib or ribociclib, in patients with metastatic breast cancer. Further research is needed to validate these findings, identify how these mutations temporally emerge under selective pressure of CDK 4/6 inhibitor, and develop rational therapeutic strategies.

Gastroesophageal adenocarcinoma (GEA) is a lethal disease where targeted therapies, even when guided by genomic biomarkers, have had limited efficacy. A potential reason for the failure of such therapies is that genomic profiling results could commonly differ between the primary and metastatic tumors. To evaluate genomic heterogeneity, we sequenced paired primary GEA and synchronous metastatic lesions across multiple cohorts, finding extensive differences in genomic alterations, including discrepancies in potentially clinically relevant alterations. Multiregion sequencing showed significant discrepancy within the primary tumor (PT) and between the PT and disseminated disease, with oncogene amplification profiles commonly discordant. In addition, a pilot analysis of cell-free DNA (cfDNA) sequencing demonstrated the feasibility of detecting genomic amplifications not detected in PT sampling. Lastly, we profiled paired primary tumors, metastatic tumors, and cfDNA from patients enrolled in the personalized antibodies for GEA (PANGEA) trial of targeted therapies in GEA and found that genomic biomarkers were recurrently discrepant between the PT and untreated metastases. Divergent primary and metastatic tissue profiling led to treatment reassignment in 32% (9/28) of patients. In discordant primary and metastatic lesions, we found 87.5% concordance for targetable alterations in metastatic tissue and cfDNA, suggesting the potential for cfDNA profiling to enhance selection of therapy. Significance: We demonstrate frequent baseline heterogeneity in targetable genomic alterations in GEA, indicating that current tissue sampling practices for biomarker testing do not effectively guide precision medicine in this disease and that routine profiling of metastatic lesions and/or cfDNA should be systematically evaluated. Cancer Discov; 8(1); 37-48. ©2017 AACR. See related commentary by Sundar and Tan, p. 14 See related article by Janjigian et al., p. 49 This article is highlighted in the In This Issue feature, p. 1 ., (©2017 American Association for Cancer Research.)

PARP1/2 inhibitors are effective against BRCA2-deficient tumors. The PARP inhibitor (PARPi) olaparib received FDA breakthrough designation for treatment of metastatic castration-resistant prostate cancers (CRPC) carrying mutations in BRCA1/2 or ATM genes. Emergent resistance to PARPi has been associated with tumor-specific BRCA2 mutations that revert the normal open reading frame rescuing homologous recombination. We describe a case of metastatic CRPC with germline BRCA2 mutation with acquired resistance to olaparib related to biallelic BRCA2 reversion mutations of both the germline and somatic loss of function alleles detected by circulating tumor DNA testing. We also summarize a retrospective analysis of 1,534 prostate cancer cases with ctDNA analysis showing a 1.6% incidence of germline BRCA2 mutations. Within the germline BRCA2 -positive cases exposed to platinum chemotherapy or PARP inhibition, the prevalence of reversion mutations was 40%. This report documents the frequency of reversion mutations in a large cohort of prostate cancer patients carrying of BRCA mutations. It also shows the potential utility of ctDNA analyses for early detection of reversion mutation driving tumor resistance.

Background: Circulating cell-free DNA (cfDNA) isolated from the plasma of cancer patients (pts) has been shown to reflect the genomic mutation profile of the tumor. However, physician and patient assessment of clinical utility of these assays in patients with metastatic colorectal cancer (mCRC) has not been previously described., Methods: Patients were prospectively consented to a prospective genomic matching protocol (Assessment of Targeted Therapies Against Colorectal Cancer [ATTACC]), with collection of blood for cfDNA extraction and sequencing of a 54-gene panel in a CLIA-certified lab. Formalin-fixed, paraffin-embedded (FFPE) tissue from prior resections or biopsies underwent 50-gene sequencing. Results from both assays were returned to the treating physicians for patient care and clinical trial selection. Follow-up surveys of treating physicians and chart reviews assessed clinical utility., Results: 128 mCRC pts were enrolled between 6/2014 and 1/2015. Results were returned in median of 13 and 26 days for cfDNA and FFPE sequencing, respectively. With cfDNA sequencing, 78% (100/128) of samples had a detectable somatic genomic alteration. 50% of cfDNA cases had potentially actionable alterations, and 60% of these could be genomically matched to at least one clinical trial in our institution. 50% (15/30) of these pts enrolled onto an identified matched trial. Physicians reported that the cfDNA testing improved the quality of care they could provide in 73% of the cases, and that 89% of pts reported greater satisfaction with the efforts to personalize experimental therapeutic agents., Conclusions: cfDNA sequencing can provide timely information on potentially actionable mutations and amplifications, thereby facilitating clinical trial enrollment and improving the perceived quality of care.

We report a HER2 T798I gatekeeper mutation in a patient with HER2 L869R -mutant breast cancer with acquired resistance to neratinib. Laboratory studies suggested that HER2 L869R is a neratinib-sensitive, gain-of-function mutation that upon dimerization with mutant HER3 E928G , also present in the breast cancer, amplifies HER2 signaling. The patient was treated with neratinib and exhibited a sustained partial response. Upon clinical progression, HER2 T798I was detected in plasma tumor cell-free DNA. Structural modeling of this acquired mutation suggested that the increased bulk of isoleucine in HER2 T798I reduces neratinib binding. Neratinib blocked HER2-mediated signaling and growth in cells expressing HER2 L869R but not HER2 L869R/T798I In contrast, afatinib and the osimertinib metabolite AZ5104 strongly suppressed HER2 L869R/T798I -induced signaling and cell growth. Acquisition of HER2 T798I upon development of resistance to neratinib in a breast cancer with an initial activating HER2 mutation suggests HER2 L869R is a driver mutation. HER2 T798I -mediated neratinib resistance may be overcome by other irreversible HER2 inhibitors like afatinib. Significance: We found an acquired HER2 gatekeeper mutation in a patient with HER2 -mutant breast cancer upon clinical progression on neratinib. We speculate that HER2 T798I may arise as a secondary mutation following response to effective HER2 tyrosine kinase inhibitors (TKI) in other cancers with HER2 -activating mutations. This resistance may be overcome by other irreversible HER2 TKIs, such as afatinib. Cancer Discov; 7(6); 575-85. ©2017 AACR. This article is highlighted in the In This Issue feature, p. 539 ., (©2017 American Association for Cancer Research.)

Background: Squamous cell carcinoma of the anal canal (SCCA) is a rare malignancy associated with infection by human papillomavirus (HPV). No consensus treatment approach exists for the treatment of metastatic disease. Because intratumoral HPV oncoproteins upregulate immune checkpoint proteins such as PD-1 to evade immune-mediated cytotoxicity, we did a trial of the anti-PD-1 antibody nivolumab for patients with metastatic SCCA., Methods: We did this single-arm, multicentre, phase 2 trial at ten academic centres in the USA. We enrolled patients with treatment-refractory metastatic SCCA, who were given nivolumab every 2 weeks (3 mg/kg). The primary endpoint was response according to Response Evaluation Criteria in Solid Tumors, version 1.1, in the intention-to-treat population. At the time of data cutoff, the study was ongoing, with patients continuing to receive treatment. The study is registered with ClinicalTrials.gov, number NCT02314169., Results: We screened 39 patients, of whom 37 were enrolled and received at least one dose of nivolumab. Among the 37 patients, nine (24% [95% CI 15-33]) had responses. There were two complete responses and seven partial responses. Grade 3 adverse events were anaemia (n=2), fatigue (n=1), rash (n=1), and hypothyroidism (n=1). No serious adverse events were reported., Interpretation: To our knowledge, this is the first completed phase 2 trial of immunotherapy for SCCA. Nivolumab is well tolerated and effective as a monotherapy for patients with metastatic SCCA. Immune checkpoint blockade appears to be a promising approach for patients with this orphan disease., Funding: National Cancer Institute/Cancer Therapy Evaluation Program, the HPV and Anal Cancer Foundation, the E B Anal Cancer Fund, The University of Texas MD Anderson Moon Shots Program, and an anonymous philanthropic donor., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Competing Interests: AUTHORS’ DISCLOSURES OF POTENTIAL CONFLICTS OF INTEREST The following represents disclosure information provided by authors of this manuscript. All relationships are considered compensated. Relationships are self-held unless noted. I = Immediate Family Member, Inst = My Institution. Relationships may not relate to the subject matter of this manuscript. For more information about ASCO’s conflict of interest policy, please refer to www.asco.org/rwc or po.ascopubs.org/site/ifc.

In vitro, EGFR inhibition, combined with the BRAF inhibitor vemurafenib, causes synergistic cytotoxicity for BRAF V600E metastatic colorectal cancer, further augmented by irinotecan. The safety and efficacy of vemurafenib, irinotecan, and cetuximab in BRAF-mutated malignancies are not defined. In this 3+3 phase I study, patients with BRAF V600E -advanced solid cancers received cetuximab and irinotecan with escalating doses of vemurafenib. Nineteen patients (18 with metastatic colorectal cancer and 1 with appendiceal cancer) were enrolled. Three patients experienced dose-limiting toxicities. The MTD of vemurafenib was 960 mg twice daily. Six of 17 evaluable patients (35%) achieved a radiographic response by Response Evaluation Criteria in Solid Tumors 1.1 criteria, consistent with in vivo models demonstrating tumor regressions with the triplet regimen. Median progression-free survival was 7.7 months. BRAF V600E circulating cell-free DNA (cfDNA) trends correlated with radiographic changes, and acquired mutations from cfDNA in genes reactivating MAPK signaling were observed at progression., Significance: Vemurafenib, in combination with irinotecan and cetuximab, was well tolerated in patients with refractory, BRAF-mutated metastatic colorectal cancer, and both survival outcomes and response rates exceeded prior reports for vemurafenib and for irinotecan plus cetuximab in BRAF V600E metastatic colorectal cancer. In vivo models demonstrated regressions with the triplet, in contrast with vemurafenib and cetuximab alone. cfDNA predicted radiographic response and identified mutations reactivating the MAPK pathway upon progression. Cancer Discov; 6(12); 1352-65. ©2016 AACR.This article is highlighted in the In This Issue feature, p. 1293., (©2016 American Association for Cancer Research.)

Ruling out malignancy in thyroid nodules historically depended on thyroid resection and histopathological evaluation until fine needle aspiration (FNA) biopsy was introduced into the United States in the 1970's. Thyroid FNA biopsy identified a majority of thyroid nodules as benign, obviating the need for surgery in over half of the patients. However, 15%-30% of thyroid FNAs have indeterminate cytology that still requires operation, even though most of these operated nodules prove to be benign post-operatively. In order to predict which cytologically indeterminate thyroid nodules are benign and to potentially avoid surgery on these nodules, a recently described commercially available Gene Expression Classifier (GEC) test (Afirma®, Veracyte, Inc., South San Francisco, CA) has been developed that can be run on the FNA sample. This paper reviews the published literature and technology assessments/guidelines by independent parties and professional groups regarding the clinical utility as well as the analytic and clinical validity of the Afirma GEC.

Diltiazem and hydrochlorothiazide are widely used to treat cardiovascular disease, often in combination. The purpose of this investigation was to determine whether a drug-drug pharmacokinetic interaction exists between diltiazem and hydrochlorothiazide. In a randomized, crossover, open study, multiple doses of diltiazem (60 mg four times daily for 21 doses) and hydrochlorothiazide (25 mg twice daily for 11 doses) were administered alone and in combination on three separate occasions to 20 healthy male volunteers. Trough and serial blood samples were collected and plasma was assayed for diltiazem, hydrochlorothiazide, and diltiazem metabolites (desacetyldiltiazem and N-desmethyldiltiazem) using HPLC. Total urine was also collected and quantified for hydrochlorothiazide. Coadministered hydrochlorothiazide did not significantly (p > 0.05) alter diltiazem (alone versus combination) steady-state maximum plasma concentration (Css(max); 145 versus 158 ng mL(-1), respectively), time to maximum plasma concentration (t(max); 3.0 versus 2.8 h, respectively); area under the plasma concentration-time curve (AUCss; 688 versus 771 ng x h mL(-1)), oral clearance (Cl(oral); 96.2 versus 88.0 L h(-1)), or elimination half-life (t(1/2); 5.2 versus 5.2 h). Similarly, administration of diltiazem did not significantly (p > 0.05) influence hydrochlorothiazide (alone versus combination) Css(max) (221 versus 288 ng mL(-1)), t(max) (1.8 versus 2.0 h), AUCss (1194 versus 1247 ng x h mL(-1)), Cl(oral) (22.4 versus 21.2 L h(-1)); t(1/2) (9.8 versus 9.6 h), or renal Cl (15.5 versus 15.2 L h(-1)). In conclusion, a clinically significant pharmacokinetic interaction between diltiazem and hydrochlorothiazide does not exist.

Dolasetron, a 5-hydroxytryptamine(3) receptor antagonist, is under investigation for prevention of nausea and vomiting due to chemotherapy. The keto-reduced metabolite of dolasetron has been identified in human plasma and is likely responsible for the antiemetic activity. This study evaluated single and multiple dose pharmacokinetics of the reduced metabolite following oral administration of dolasetron mesylate in healthy male subjects. Five groups (six active/two placebo each) of subjects received either oral doses of dolasetron mesylate ranging from 25 to 200 mg or placebo on day 1 and every 12 h on days 2 through 9. Because plasma dolasetron concentrations were low and sporadic, pharmacokinetics of the parent compound could not be determined. The reduced metabolite appeared rapidly in the plasma and reached a maximal plasma concentration in about 1 h. The maximal plasma concentrations and areas under plasma concentration--time curves were proportional to the dose. The mean apparent oral clearance ranged from 9.89 to 23.10 ml min(minus sign1) kg(minus sign1). The half-life ranged from 5.20 to 10.80 h. Mean renal clearance and fraction of dose excreted in urine were 0.97 to 3.97 ml min(minus sign1) kg(minus sign1) and 7.47 to 31.9%, respectively. The pharmacokinetics of reduced metabolite appears to be dose independent after single and multiple dosing.

Purpose: The purpose of this study was to investigate the percutaneous absorption of ketoprofen applied topically to different anatomical sites on the body., Methods: The study design was a randomized, four-way crossover in 24 healthy male subjects. One gram of ketoprofen 3% gel (30 mg dose) was applied every six hours for 25 doses over a 100 cm2 of the back, arm, and knee. A 0.5 ml of ketoprofen solution (60 mg/ml) was applied to the back as a reference treatment. Plasma and urine samples were obtained for the assay of racemic ketoprofen and ketoprofen enantiomers (S and R), respectively., Results: The relative bioavailabilities of ketoprofen gel were 0.90 +/- 0.50, 1.08 +/- 0.63, and 0.74 +/- 0.38 when applied to the back, arm, and knee, respectively. The plasma ketoprofen C(max) for gel applied to the back and arm are similar (p > 0.05) but C(max) was lower when applied to the knee (p < 0.05). The time to C(max) ranged from 2.7 to 4.0 hours and was similar for gel treatments on the back and arm, but no longer for the knee treatment. The fraction of dose excreted in urine as total S and R enantiomers ranged from 5.41 to 9.10%., Conclusions: The percutaneous absorption of ketoprofen was similar when applied to either the back or arm but was lower when applied to the knee.

Dolasetron, Anzemet, a 5-hydroxytryptamine receptor antagonist, is under investigation as an antiemetic agent. The keto-reduced metabolite of dolasetron has been identified in human plasma and is probably responsible for the majority of the antiemetic activity. This study evaluated the pharmacokinetics of dolasetron and the reduced metabolite following single and multiple intravenous (IV) infusions of dolasetron mesylate in healthy male subjects. Four groups of subjects (six active/two placebo) received either dolasetron mesylate or placebo in single IV doses ranging from 0.30 to 0.60 mg kg-1 on day 1 and multiple IV doses ranging from 0.60 to 1.20 mg kg-1 d-1 on days 2-9. Dolasetron could be detected for less than 1 h, while the reduced metabolite appeared rapidly in the plasma, reaching a maximal plasma concentration in less than 1 h. Reduced metabolic maximal plasma concentration was proportional to the dose and the area under plasma concentration curve was linear based on regression analysis. The half-life of reduced metabolite ranged from 3.82 to 7.46 h. The mean renal clearance of reduced metabolite was 2.20-4.43 mL min-1 kg-1 and was dose independent. All of the evidence supports dose independent pharmacokinetics for the reduced metabolite. Upon multiple dosing, the reduced metabolite AUC can be predicted from the single-dose pharmacokinetics of this metabolite.

One gram single dose of Pentasa controlled-release capsules was administered to 24 healthy volunteers under fasting condition. Mean plasma 5-aminosalicylic acid (5-ASA) and acetyl 5-ASA concentrations peaked at 0.53 microgram.ml-1 and 1.33 micrograms.ml-1 from 3 to 4 hours following dosing, respectively. The half-lives of both compounds could not be determined as absorption of 5-ASA was continuous throughout the gastrointestinal tract. An average of 29.4% (CV: 27%) of the dose was excreted in the urine primarily as acetyl 5-ASA. Up to 91.1% of the dose was released from the capsules. Forty percent of the dose (CV: 40%) was eliminated in the feces, with 8.9% of the dose remained as formulation bounded 5-ASA, indicating that controlled-release capsules continue to release drug throughout the GI tract. 5-ASA contributed 46.7% of the salicylates eliminated in the feces and acetyl 5-ASA accounted for the balance. Controlled-release capsules produced three times more total salicylates and 10 times more total and free 5-ASA in the feces than did 5-ASA suspension. Thus, while lower systemic levels of salicylates were absorbed, greater therapeutic quantities of 5-ASA were available in the bowel.

Multiple oral doses of diltiazem (DTZ) and propranolol (PPL, 60 mg every 8 h daily for 13 doses) were administered to 14 healthy volunteers alone and in combination on three separate occasions. Serial blood samples were collected up to 24 h after dose 13 on day 5 to determine possible pharmacokinetic interactions between the two drugs. When administered alone, DTZ concentration peaked at 161.4 ng ml-1 3 h following the final dose with an elimination half-life of 6.1 h. DTZ oral clearance was 65.1 l h-1. PPL did not affect DTZ oral clearance and half-life during the combination treatment. However, DTZ tmax was extended from 2.9 h to 3.5 h (p less than 0.05) and Cmax was 144.7 ng ml-1. Unlike the parent drug DTZ, desacetyldiltiazem (DAD) plasma profile was elevated during the combination treatment. DAD Cmax and AUC both increased approximately 20 per cent (p less than 0.05). PPL pharmacokinetics were altered as well. Oral clearance of PPL decreased from 80.4 l h-1 to 61.0 l h-1 while the half-life increased from 5.9 h to 8.0 h (p less than 0.05). PPL Cmax increased from 155.1 ng ml-1 to 167.5 ng ml-1.

Single doses of 1 gm 5-aminosalicylic acid (5-ASA) suspension was administered to 24 healthy volunteers during both fasting and fed conditions. For subjects in a fasting state, plasma 5-ASA and acetyl 5-ASA concentrations peaked rapidly 1 hour after dosing to 14.72 micrograms/ml and 11.4 micrograms/ml, respectively. The elimination half-life of 5-ASA was 51.9 minutes, whereas the acetyl 5-ASA half-life could not be determined. A mean of 78.3% of the dose was excreted in the urine, with 5-ASA accounting for 21.2% of the dose and acetyl 5-ASA accounting for the balance. Only 11.3% of the dose was eliminated in the feces, consisting mostly of acetyl 5-ASA. Food coadministration reduced 5-ASA and acetyl 5-ASA systemic relative bioavailability to 44% and 76%, respectively, compared with the fasting treatment. Urinary excretion of the salicylates was reduced to 46.8%, and fecal salicylate elimination increased almost 100%--to 24.2% of the total dose.

Twenty-four healthy male subjects were administered 300 mg of propafenone every 8 h for 6 d in each of two phases that were separated by 2 d. Plasma samples were collected during the approach to steady state for each phase, and plasma and saliva samples were collected frequently at steady state. Both plasma and saliva propafenone were assayed by a specific HPLC method. Two estimates of elimination half-life (t1/2), mean steady-state concentration (CPss), time to maximal concentration (tmax), and maximal concentration (CPmax) were estimated for each subject. Also mean steady-state saliva concentrations (CSss), time to maximal saliva concentration (tSmax), and maximal saliva concentrations (CSmax) were estimated. A large intersubject variance in both t1/2 and CPss were observed in the 24 subjects, with the t1/2 values ranging from 2.1 to 27.2 h and the CPss values from 0.3 to 3.03 microgram/mL. Each subject was quite consistent for the two phases, suggesting a relatively low intrasubject variance for propafenone kinetics. A histogram shows most subjects to have t1/2 values between 2 and 10 h, with diminishing numbers of subjects at greater t1/2 values rather than a bimodal distribution. Saliva concentrations ranged from 12 to 72% of the corresponding plasma concentrations, being 24.7 +/- 11.1% of the simultaneously collected plasma sample overall (mean +/- SD). a significant (p less than 0.001) positive correlation exists between CPss and CSss.

Dothiepin hydrochloride (N,N-dimethyldibenzo[b,e]thiepin-delta 11(6 H), gamma-propylamine hydrochloride) is a tricyclic antidepressant which is structurally similar to amitriptyline. Twenty-seven healthy men received three single oral doses of 50-, 100-, and 150-mg dothiepin hydrochloride capsules in a three-way randomized, crossover dose-proportionality study. Plasma concentration-time profiles of dothiepin (1) were described by both one- and two-compartment models with first-order absorption. The total intrinsic clearance of dothiepin decreased from 165.5 to 121.1 L/h as the dose was increased from 50 to 150 mg, but there was no significant effect on the terminal half-life (approximately 20 h). Plasma concentration-time profiles of the three major metabolites of dothiepin, the S-oxide derivative of dothiepin, N,N-dimethyl[b,e]thiepin-delta 11(6 H), gamma-propylamine 5-oxide (2), the demethyl derivative, N-methyldibenzo[b,e]thiepin-delta 11(6 H), gamma-propylamine (3) and the demethyl S-oxide derivative N-methyldibenzo[b,e]thiepin-delta 11(6 H), gamma-propylamine 5-oxide (4), were described by a one-compartment model with apparent first-order formation. The AUC infinity values of the S-oxide 2 and the demethyl S-oxide 4 increased proportionally with dose. The dose proportionality of the demethyl metabolite 3 may not be ascertained from the data in this study. The corresponding half-lives of the three metabolites, which are dose independent, were approximately 24, 28, and 40 h, respectively.

The binding of various radioisotopically labeled organic compounds to rat liver and lung was investigated in vitro. Pieces of rat lung and slices of rat liver were incubated at 37 degrees C under a nitrogen atmosphere in a modified Krebs-Ringer phosphate solution (pH 7.4) CONTAININg the compound to be studied. Of the neutral compounds investigated, digitoxin, digoxin and dexamethasone were highly bound to both liver and lung tissue, whereas the degree of binding of amitrole, erythritol, and ouabain was 20% or less. The weak acids which were bound to the greatest extent in both liver and lung were phenobarbital, pentobarbital, and diphenylhydantoin. Barbital was poorly bound, and there was no evidence for the binding of 5,5-dimethyloxazolidine-2,4-dione or p-aminohippuric acid in either tissue. Binding of the cardiac glycosides and the barbiturates directly paralleled their lipid solubilities. The degree of binding of neutral compounds and weak acids to lung and liver tissue did not vary greatly with concentration, even though broad concentration ranges were studied. This was also true of the weak base morphine. On the other hand, the binding to liver and lung of the organic bases nicotine, pilocarpine, d-amphetamine, lidocaine, erythromycin, and chloroquine, did vary with concentration. The quaternary ammonium compound decamethonium was bound only to liver, and this binding also varied with concentration. Two additional quaternary ammonium compounds, tetraethylammonium and N1-methylnicotinamide, were not significantly bound to either tissue. Comparisons on the basis of equal content of solids revealed that the binding of diverse organic compounds in liver is greater than or equal to that in lung.

The effect of food intake on the bioavailability of propafenone, a new antiarrhythmic agent, was evaluated by comparing its kinetics in 24 healthy volunteers in a fasted state and after a standard breakfast. With food, the maximum plasma drug concentration was reached earlier and was significantly increased. When data from 'slow' metabolizers were excluded, there was an average increase of 147% in the area under the concentration-time curve (AUCo) following the standard breakfast. There was a significant correlation (r = 0.946) between [(AUCo fed - AUCo fasted)/AUCo fasted] and propafenone intrinsic clearance in the fasted state. Food intake, however, does not appear to affect the bioavailability of propafenone in 'slow' metabolizers. Patients should be advised to take propafenone in a constant relationship to food to assure consistent bioavailability.

Caffeine is generally regarded as a safe drug, as evidenced by its wide availability in "over-the-counter" preparations and beverages. However, it is capable of producing a lethal outcome in cases of intoxication. The case of a two-year-old girl, who suffered major poisoning from caffeine, is presented. Her care, including the use of peritoneal dialysis, is discussed. Previous cases of caffeine intoxication meriting hospital care or resulting in death which have been reported in the English language medical literature are summarized. It is suggested that drug-drug interactions and the use of peritoneal dialysis and hemoperfusion be given particular consideration in such patients.

A two-way complete crossover bioavailability study of solutions of theophylline given orally or rectally in 16 healthy subjects was conducted. Blood samples were obtained prior to dosing and at 0.25, 0.5, 0.75, 1, 1.5, 2, 2,5, 3, 3,5, 4, 4.5, 5, 6, 7, 8, 10, 12, and 24 hr. Plasma theophylline was determined by high-pressure liquid chromatography. In the fasting subjects solutions given orally were absorbed faster (0.95 versus 1.95 hr to peak), reaching a higher peak concentration (7.26 versus 4.87 microgram/ml) than the solutions given rectally. Depending on the method of computation, solutions given rectally were estimated to be 86% to 87% as biovailable as the solutions given orally, with 75% of the subjects having 80% or greater relative bioavailability.

The role which carrier-mediated transport and passive diffusion play in the clearance of quaternary ammonium compounds from cerebrospinal fluid was evaluated by ventriculocisternal perfusion in rabbits by using [14C]choline as the primary test compound. Choline was transported out of cerebrospinal fluid by two processes: a saturable, carrier-mediated process with a Tmax of 70.5 ng/min and Kt of 2.2 microgram/min; and, a passive nonsaturable process with a cerebrospinal fluid perfusate clearance of 11.5 microliter/min. N1-methylnicotinamide depressed the clearance of choline as well as that of hexamethonium, suggesting that these cations share a common transport process. Ouabain reduced the clearance of choline and hexamethonium. Passage of choline into brain occurred by passive diffusion.