Clinical and analytical validation of FoundationOne®CDx, a comprehensive genomic profiling assay for solid tumorsFoundationOne®CDx (F1CDx) is a United States (US) Food and Drug Administration (FDA)-approved companion diagnostic test to identify patients who may benefit from treatment in accordance with the approved therapeutic product labeling for 28 drug therapies. F1CDx utilizes next-generation sequencing (NGS)-based comprehensive genomic profiling (CGP) technology to examine 324 cancer genes in solid tumors. F1CDx reports known and likely pathogenic short variants (SVs), copy number alterations (CNAs), and select rearrangements, as well as complex biomarkers including tumor mutational burden (TMB) and microsatellite instability (MSI), in addition to genomic loss of heterozygosity (gLOH) in ovarian cancer. CGP services can reduce the complexity of biomarker testing, enabling precision medicine to improve treatment decision-making and outcomes for cancer patients, but only if test results are reliable, accurate, and validated clinically and analytically to the highest standard available. The analyses presented herein demonstrate the extensive analytical and clinical validation supporting the F1CDx initial and subsequent FDA approvals to ensure high sensitivity, specificity, and reliability of the data reported. The analytical validation included several in-depth evaluations of F1CDx assay performance including limit of detection (LoD), limit of blank (LoB), precision, and orthogonal concordance for SVs (including base substitutions [SUBs] and insertions/deletions [INDELs]), CNAs (including amplifications and homozygous deletions), genomic rearrangements, and select complex biomarkers. The assay validation of >30,000 test results comprises a considerable and increasing body of evidence that supports the clinical utility of F1CDx to match patients with solid tumors to targeted therapies or immunotherapies based on their tumor's genomic alterations and biomarkers. F1CDx meets the clinical needs of providers and patients to receive guideline-based biomarker testing, helping them keep pace with a rapidly evolving field of medicine.
Rare Variant Analysis for Family-Based DesignGenome-wide association studies have been able to identify disease associations with many common variants; however most of the estimated genetic contribution explained by these variants appears to be very modest. Rare variants are thought to have larger effect sizes compared to common SNPs but effects of rare variants cannot be tested in the GWAS setting. Here we propose a novel method to test for association of rare variants obtained by sequencing in family-based samples by collapsing the standard family-based association test (FBAT) statistic over a region of interest. We also propose a suitable weighting scheme so that low frequency SNPs that may be enriched in functional variants can be upweighted compared to common variants. Using simulations we show that the family-based methods perform at par with the population-based methods under no population stratification. By construction, family-based tests are completely robust to population stratification; we show that our proposed methods remain valid even when population stratification is present.
Evaluation of IFITM3 rs12252 Association With Severe Pediatric Influenza InfectionAdrienne G. Randolph, Wai‐Ki Yip, E. Kaitlynn Allen et al.|The Journal of Infectious Diseases|2017 Background: Interferon-induced transmembrane protein 3 (IFITM3) restricts endocytic fusion of influenza virus. IFITM3 rs12252_C, a putative alternate splice site, has been associated with influenza severity in adults. IFITM3 has not been evaluated in pediatric influenza. Methods: The Pediatric Influenza (PICFLU) study enrolled children with suspected influenza infection across 38 pediatric intensive care units during November 2008 to April 2016. IFITM3 was sequenced in patients and parents were genotyped for specific variants for family-based association testing. rs12252 was genotyped in 54 African-American pediatric outpatients with influenza (FLU09), included in the population-based comparisons with 1000 genomes. Splice site analysis of rs12252_C was performed using PICFLU and FLU09 patient RNA. Results: In PICFLU, 358 children had influenza infection. We identified 22 rs12252_C homozygotes in 185 white non-Hispanic children. rs12252_C was not associated with influenza infection in population or family-based analyses. We did not identify the Δ21 IFITM3 isoform in RNAseq data. The rs12252 genotype was not associated with IFITM3 expression levels, nor with critical illness severity. No novel rare IFITM3 functional variants were identified. Conclusions: rs12252 was not associated with susceptibility to influenza-related critical illness in children or with critical illness severity. Our data also do not support it being a splice site.
Phase III Randomized Study of 4 Weeks of High-Dose Interferon-α-2b in Stage T2bNO, T3a-bNO, T4a-bNO, and T1-4N1a-2a (microscopic) Melanoma: A Trial of the Eastern Cooperative Oncology Group–American College of Radiology Imaging Network Cancer Research Group (E1697)Sanjiv S. Agarwala, Sandra J. Lee, Wai‐Ki Yip et al.|Journal of Clinical Oncology|2017 Purpose To test the efficacy of 4 weeks of intravenous (IV) induction with high-dose interferon (IFN) as part of the Eastern Cooperative Oncology Group regimen compared with observation (OBS) in patients with surgically resected intermediate-risk melanoma. Patients and Methods In this intergroup international trial, eligible patients had surgically resected cutaneous melanoma in the following categories: (1) T2bN0, (2) T3a-bN0, (3) T4a-bN0, and (4) T1-4N1a-2a (microscopic). Patients were randomly assigned to receive IFN α-2b at 20 MU/m 2 /d IV for 5 days (Monday to Friday) every week for 4 weeks (IFN) or OBS. Stratification factors were pathologic lymph node status, lymph node staging procedure, Breslow depth, ulceration of the primary lesion, and disease stage. The primary end point was relapse-free survival. Secondary end points included overall survival, toxicity, and quality of life. Results A total of 1,150 patients were randomly assigned. At a median follow-up of 7 years, the 5-year relapse-free survival rate was 0.70 (95% CI, 0.66 to 0.74) for OBS and 0.70, (95% CI, 0.66 to 0.74) for IFN ( P = .964). The 5-year overall survival rate was 0.83 (95% CI, 0.79 to 0.86) for OBS and 0.83 (95% CI, 0.80 to 0.86) for IFN ( P = .558). Treatment-related grade 3 and higher toxicity was 4.6% versus 57.9% for OBS and IFN, respectively ( P < .001). Quality of life was worse for the treated group. Conclusion Four weeks of IV induction as part of the Eastern Cooperative Oncology Group high-dose IFN regimen is not better than OBS alone for patients with intermediate-risk melanoma as defined in this trial.
The rare <i>TREM2</i> R47H variant exerts only a modest effect on Alzheimer disease riskOBJECTIVES: Recently, 2 independent studies reported that a rare missense variant, rs75932628 (R47H), in exon 2 of the gene encoding the "triggering receptor expressed on myeloid cells 2" (TREM2) significantly increases the risk of Alzheimer disease (AD) with an effect size comparable to that of the APOE ε4 allele. METHODS: In this study, we attempted to replicate the association between rs75932628 and AD risk by directly genotyping rs75932628 in 2 independent Caucasian family cohorts consisting of 927 families (with 1,777 affected and 1,235 unaffected) and in 2 Caucasian case-control cohorts composed of 1,314 cases and 1,609 controls. In addition, we imputed genotypes in 3 independent Caucasian case-control cohorts containing 1,906 cases and 1,503 controls. RESULTS: Meta-analysis of the 2 family-based and the 5 case-control cohorts yielded a p value of 0.0029, while the overall summary estimate (using case-control data only) resulted in an odds ratio of 1.67 (95% confidence interval 0.95-2.92) for the association between the TREM2 R47H and increased AD risk. CONCLUSIONS: While our results serve to confirm the association between R47H and risk of AD, the observed effect on risk was substantially smaller than that previously reported.