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Immune checkpoint inhibition with monoclonal antibodies has emerged as a promising therapeutic approach but in most tumor types responses are unpredictable and observed in a minority of treated patients. Positive and negative predictive biomarkers for efficacy of these costly drugs are desperately needed. Immunohistochemistry (IHC) for programmed death ligand (PD-L1) expression in tumor and inflammatory infiltrate has emerged as one predictive biomarker of some value. However, multiple confounders including those inherent to any IHC and the unique complexities of the biology of the immune response have limited its utility. Tumor mutational burden (TMB) has emerged as a seemingly more promising predictive biomarker for immunotherapy with checkpoint inhibitors in several tumor types and is likely to be incorporated into future treatment algorithms for these agents. Given this, the need to define and standardize key parameters of the most promising biomarkers becomes essential to allow all stakeholders to make meaningful observations and inferences as to the efficacy of ostensibly similar agents and combinations in various settings. This review briefly summarizes approaches to measurement of TMB and ongoing efforts to achieve harmonization of this key biomarker.

Introduction Increased development and use of next-generation sequencing in clinical diagnostics has revolutionized precision medicine. Steps prior to a specimen arriving at a diagnostic facility, including pathological evaluation, are crucial parameters determining specimen quality and success of comprehensive genomic profiling (CGP). This observational study identified factors that may influence tissue acquisition for commercial CGP in clinical oncology. Methods Data were collected from deidentified patients (n = 63) from select US pathology labs enrolled in a Foundation Medicine (FMI) early access program for the CGP test FoundationOne CDx (Foundation Medicine). A representative substudy cohort (n = 20) with qualitative information available was selected. Lab visit frequency by FMI was monitored for 42 cases. Tissue acquisition turnaround time (TA-TAT) was separated into stages: (1) tissue request to pathology lab acknowledgment, (2) pathology lab acknowledgment to tissue pathology review, (3) tissue pathology review to packaging, and (4) packaging to tissue arriving at FMI. Results Median TA-TAT for the total population was 5.0 days (range, 0-27.0) and 3.5 days for the substudy cohort (range, 1.0-11.0). The duration of each TA-TAT stage was evaluated separately and varied between labs (0%-71.4% of total TA-TAT). TA-TAT was longer for unstained slides compared with formalin-fixed, paraffin-embedded (FFPE) tissue blocks. There was a trend for decreased TA-TAT when stages 1 and 2 occurred on the same day versus different days. For the cases with lab-visit frequency reported, those with biweekly visits had shorter TA-TAT (biweekly: n = 12, median = 2.0, 2.5th-97.5th percentile range, 0.3-5.7 days; single visit: n = 30, median = 5.5, 2.5th-97.5th percentile range, 0.7-13.1 days). Conclusions Understanding and optimizing the tissue acquisition workflow may reduce TA-TAT, thereby facilitating report delivery and subsequent treatment guidance to patients. Funding Bristol-Myers Squibb. Professional medical writing and editorial assistance was provided by Katerina Pipili, PhD, and Jay Rathi, MA, of Spark Medica Inc, funded by Bristol-Myers Squibb.

Background. FNAC are generated during the FNA procedure - for example, commonly used in conjunction with endobronchial ultrasound (EBUS-FNA) as a minimally invasive tool for the diagnosis and management of non small-cell lung cancer (NSCLC) - as a histologic QC for the presence of malignant cells. Formalin-fixed core biopsies and aspirate cell blocks (FNACB) are then created for comprehensive genomic profiling (CGP). However, the routine pathology workup may render the FNACB unable to generate a CGP result, while the FNAC remain in reserve. In the current study we performed a retrospective multi-cancer, multi-institutional analysis of FNAC performance, including computed tumor purity analysis, using a regulated commercial grade CGP assay. Experimental procedures. 119 FNAC met minimum specimen cellularity (10K total cellularity) and DNA extraction (50ng) criteria for CGP. Extracted DNA from FNACS underwent hybrid-capture-based CGP for all classes of genomic alterations in 315 genes. Tumor mutational burden (TMB) was determined on 1.1 Mbp of sequenced DNA and microsatellite instability (MSI) was determined on 114 loci. A comparison set of 182 FNACB specimens underwent the same CGP assay. Individual specimen CGPs were annotated as Pass, Fail, or Qualified per computational biology standard procedures that factor in sequencing quality metrics such as mean target coverage and computational tumor purity modeling. Results. The 119 FNAC, collected at 14 different medical facilities, encompassed 44 distinct tumor disease ontologies (DO) from 17 unique anatomic biopsy sites. 105 of 119 FNACS (88%) received a passing report, 10 (8%) were qualified, and 4 (3%) failed. In the FNACB comparison group, 155 of 182 reports were pass (85%), 22 qualified (12%), and 5 failed (3%). The number of passing reports in FNACS versus FNACB was equivalent (P=0.5). The FNAC had a significantly higher mean target coverage than FNACB (703 vs 665; P= 0.04995). The average computational tumor purity metric was significantly higher in FNACS than in FNACB (57.9% vs. 45.3%; P=0.00001). Conclusions. This study provides new data from FNAC that further support their utility for clinical testing. FNAC derived from multiple medical facilities, biopsy sites, and tumor types were found to be equivalent or superior to FNACB for CGP. Finally, the relative cellular homogeneity and high tumor cell content of both FNAC and FNACB likely confirms the discohesiveness of malignant cells and enables CGP without required enrichment given that macrodissection would be challenging for these samples in a daily practice setting. Citation Format: Jonathan K. Killian, Dean Pavlick, Lindsay Croshier, John Truesdell, Chris Wright, Tim Brennan, Vera Banning, Lazaro Garcia, Laurie Gay, Gene Stirchak, Jo-Anne Vergilio, Christine Malboeuf, Nhu Ngo, Julia Elvin, Siraj Ali, Vince Miller, Jeffrey S. Ross. A multi-institutional, multi-tumor analysis of fine needle aspiration (FNA) cytology smear (FNAC) performance in clinical comprehensive genomic profiling [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2019; 2019 Mar 29-Apr 3; Atlanta, GA. Philadelphia (PA): AACR; Cancer Res 2019;79(13 Suppl):Abstract nr 1694.

Introduction: Increase in targeted therapies has resulted in the need for a single assay capable of detecting diverse biomarkers indicated for these agents. Comprehensive genomic profiling (CGP) provides such a solution, but due to the complexity and number of assays available today, standardization of validation has become critically important. We present FoundationOne CDx, the first NGS-based comprehensive companion diagnostics (CDx) platform developed and performed in compliance with FDA 21 CFR part 820. The assay interrogates 324 genes, and has CDx indications in five tumor types associated with 17 targeted therapies (Table 1). The versatile assay design will facilitate streamlined development of future CDx indications. Methods: DNA extracted from FFPE tumor tissue underwent whole-genome shotgun library construction and hybridization-based capture, followed by sequencing using Illumina HiSeq 4000. Sequence data were processed using a proprietary analysis pipeline designed to detect base substitutions, indels, copy number alterations, rearrangements, microsatellite instability (MSI), and tumor mutational burden (TMB). Results: Clinical validity was established such that the concordance between CGP and approved CDx were statistically non-inferior to that of two runs of approved CDx. For analytical validity, limit of detection (LoD) was at allele frequency 4% for known substitutions and indels. LoD was 16% tumor content for copy number amplifications, 30% for homozygous deletions, 11% for rearrangements, 12% for MSI, and 20% for TMB. Concordance with an orthogonal NGS platform was 94.6% for substitutions and indels. Within-assay reproducibility had PPA 99.4%. Conclusion: Rapid expansion of targeted therapies and CDx has necessitated a new approach and urgency to defining performance standards. We developed a comprehensive CDx assay and demonstrated clinical and analytical validity to support and accelerate using CGP for routine clinical care. Table 1. Companion Diagnostic IndicationsIndicationBiomarkerTherapyNon-small cell lung cancer (NSCLC)EGFR exon 19 deletions and EGFR exon 21 L858R alterationsafatinib, gefitinib, or erlotinibEGFR exon 20 T790M alterationsosimertinibALK rearrangementsalectinib, crizotinib, or ceritinibBRAF V600Edabrafenib in combination with trametinibMelanomaBRAF V600Edabrafenib, vemurafenibBRAF V600E and V600Ktrametinib, cobimetinib, in combination with vemurafenibBreast cancerERBB2 (HER2) amplificationtrastuzumab, ado-trastuzumab-emtansine, or pertuzumabColorectal cancerKRAS wild-type (absence of mutations in codons 12 and 13)cetuximabKRAS and NRAS wild-type (absence of mutations in exons 2, 3, and 4)panitumumabOvarian cancerBRCA1/2 alterationsrucaparib Citation Format: James X. Sun, Yali Li, Coren Milbury, Joel Skoletsky, Christine Burns, Wai-ki Yip, Jun Luo, Ninad Dewal, Adrienne Johnson, Kyle Gowen, Jing Tong, Yuting He, Jie He, Pei Ma, Jared White, Steve Roels, John Truesdell, Eric Peters, Houston Gilbert, Charlie Wu, Erica Schleifman, Johannes Noe, Carl Barrett, Kenneth Thress, Suzanne Jenkins, Julia Elvin, Geoff Otto, Doron Lipson, Jeffrey Ross, Vincent Miller, Philip Stephens, Michael Doherty, Christine Vietz. A clinically validated comprehensive companion diagnostic platform for care of patients with advanced cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4757.

Introduction: Patients with HER2-positive breast cancer may benefit from targeted therapies including trastuzumab and pertuzumab. While FDA has approved companion diagnostics (CDx) using FISH or IHC for identifying ERBB2 amplifications, molecular diagnostic testing in breast cancer is rapidly evolving towards comprehensive genomic profiling (CGP) due to an increasing number of biomarkers. However, clinical validity of ERBB2 testing in CGP has not yet been demonstrated in an FDA-approved manner. We present the first ERBB2 test using NGS as a follow-on CDx, which is part of FoundationOne CDx (F1CDx). Methods: Clinical validity was established against the FDA-approved HER2 FISH test, using retrospective breast cancer patient samples. For each sample, two tests using the FISH assay were performed, and clinical validity was established such that the F1CDx result is statistically non-inferior to the performance between two runs of FISH. Concordance was calculated on samples that agree between the two FISH tests. Results: Results are shown in Table 1. An exploratory analysis including low-level ERBB2 amplifications (CN=4; ploidy+2) detected by F1CDx demonstrated an improved PPA of 93.8%. A non-inferiority test demonstrated a margin of 8.0%. Further analysis showed that the discordance is most significant among samples with a low FISH ratio. In samples that are FISH-positive but F1CDx-negative, a second test of FISH only yields a FISH-FISH concordance of only 55%, suggesting significantly decreased FISH-FISH reproducibility. Conclusion: We presented a follow-on CDx for ERBB2. The F1CDx platform provides a single assay that identifies cancer patients who may be eligible to receive FDA-approved targeted therapeutics, conserves tissue by avoiding serial testing and can serve as clinical trial assay for studies requiring a molecular biomarker for eligibility. The data demonstrating clinical and analytical validity of ERBB2 may accelerate the use of CGP for routine clinical use. Table 1. The ERBB2 companion diagnostic in FoundationOne CDxCompanion diagnosticERBB2 amplificationIndicated useTrastuzumab, ado-trastuzumab-emtansine, or pertuzumab in breast cancerApproved CDx comparatorHER2 FISH PharmDx® Kit (Dako Denmark A/S)Positive percent agreement (PPA)89.4% (101/113)Negative percent agreement (NPA)98.4% (180/183)Median unique sequence coverage>500XPrecision100%Limit of Detection19.7% tumor content Citation Format: Wai-ki Yip, Joel Skoletsky, Pei Ma, Jun Luo, Coren Milbury, Christine Burns, John Truesdell, Julia Elvin, Geoff Otto, Doron Lipson, Jeffrey Ross, Vincent Miller, Philip Stephens, Michael Doherty, Christine Vietz, James X. Sun, Yali Li. An ERBB2 follow-on companion diagnostic for clinical care of patients with breast cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 1607.

Introduction: In patients with advanced-stage ovarian cancer, FDA has recently granted approval of treatment with PARP inhibitors (PARPi) in patients harboring deleterious BRCA mutations (~25% of population). However, there is clear evidence of “BRCA-like” patients who respond to PARPi without BRCA mutations. To identify such patients, it has been shown that deficiency in homologous recombination repair leads to a common phenotype of genome-wide loss of heterozygosity (LOH). Depending on the cutoff employed, genomic LOH could identify more than twice the number of ovarian cancer patients who could benefit from PARPi than measuring BRCA alone. We present here an NGS-based platform developed and performed in compliance with FDA 21 CFR part 820. The assay provides a tumor measurement of BRCA1/2 (FDA-approved as FoundationFocus CDx BRCA) as well as genomic LOH, and is on the same platform as the comprehensive FoundationOne CDx, which interrogates 324 genes. Methods: DNA extracted from FFPE tumor tissue underwent whole-genome shotgun library construction and hybridization-based capture, followed by sequencing using Illumina HiSeq 4000. Sequence data were processed using a proprietary analysis pipeline designed to detect base substitutions, indels, copy number alterations (CNA), genomic rearrangements, microsatellite instability (MSI), and tumor mutational burden (TMB). A genome-wide LOH profile based on SNPs is measured as part of the CNA pipeline, and is summarized as the percentage of the tumor genome displaying LOH (scored from 0-100%), with ≥16% being considered LOH high based on clinical data derived from ARIEL2 Part 1, a phase II study of the PARPi rucaparib for the treatment of platinum-sensitive ovarian cancer (ARIEL2; NCT01891344) Results: For analytical validity, BRCA limit of detection (LoD) was at allele frequency 5.9% for substitutions and non-repetitive indels, and 30% tumor content for LOH. Overall percent agreement with comparator NGS assay was 97.3% for BRCA. No orthogonal platform concordance was established for LOH as no validated test exists. Within-assay reproducibility was measured with overall concordance of 100% for BRCA, and 98% for LOH. Conclusion: We developed a novel diagnostic assay (in compliance with FDA 21 CFR part 820) that can measure BRCA and genomic LOH simultaneously, and established robust analytical validation data. Citation Format: James X. Sun, Kevin Lin, Yali Li, Kyle Gowen, Yuting He, Coren Milbury, Christine Burns, Jun Luo, Steve Roels, Murtaza Mehdi, John Truesdell, Pei Ma, Lakshman Ramamurthy, Christine Vietz, Jeri Beltman, Thomas Harding, Doron Lipson, Jeffrey Ross, Vincent Miller, Philip Stephens, Michael Doherty, Julia Elvin. A validated diagnostic assay for identifying ovarian cancer patients with deleterious BRCA mutations and high genomic loss of heterozygosity (LOH) [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2018; 2018 Apr 14-18; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2018;78(13 Suppl):Abstract nr 4544.

Biological RNAs contain a variety of post-transcriptional modifications that facilitate their efficient function in the cellular environment. One of the two most common forms of modification is methylation of the 2'-hydroxyl group of the ribose sugar, which is performed by a number of S-adenosylmethionine (SAM) dependent methyltransferases. In bacteria, many of these modifications in tRNA and rRNA are carried out by the alpha/beta-knot superfamily of enzymes, whose SAM-binding pocket is created by a characteristic deep trefoil knot. TrmH, an enzyme found throughout all three kingdoms of life, modifies the universally conserved guanosine 18 position of tRNA. The crystal structure of TrmH from the thermophilic bacterium Aquifex aeolicus has been determined at 1.85 A resolution using data collected from a synchrotron-radiation source. The protein reveals a fold typical of members of the SpoU clan of proteins, a subfamily of the alpha/beta-knot superfamily, with alpha-helical extensions at the N- and C-termini that are likely to be involved in tRNA binding.

This paper re-examines the likely consequences for the economics of re-opening the Canal in light of current important developments in bunker oil prices, ship acquisition costs, and changing ship insurance rate structures. A previous recent article in this journal (Gribbin, 1975) made vital but seriously erroneous futuristic assumptions which when corrected reverse dramatically the general conclusions that bigger tankers are better and that continued enlarging of the Canal is in order. This study provides analysis of the economics of larger ships, a re-analysis of the economics of using the Canal with its 1967 limitations, and an analysis of the planned expanded version of the Canal allowing much larger ships to pass in 1980.