Clinical Validation of a 106-SNV MALDI-ToF MS Pharmacogenomic Panel.

BACKGROUND: Laboratorians have the opportunity to help minimize the frequency of adverse drug reactions by implementing pharmacogenomic testing and alerting care providers to possible patient/drug incompatibilities before drug treatment is initiated. Methods combining PCR with MALDI-ToF MS have allowed for sensitive, economical, and multiplexed pharmacogenomic testing results to be delivered in a timely fashion. METHOD: This study evaluated the analytical performance of the Agena Biosciences iPLEX® PGx 74 panel and a custom iPLEX panel on a MassARRAY MALDI-TOF MS instrument in a clinical laboratory setting. Collectively, these panels evaluate 112 SNVs across 34 genes implicated in drug response. Using commercially available samples (Coriell Biorepository) and in-house extracted DNA, we determined ideal reaction conditions and assessed accuracy, precision, and robustness. RESULTS: Following protocol optimization, the Agena PGx74 and custom panels demonstrated 100% concordance with the 1000 Genomes Project Database and clinically validated hydrolysis probe genotyping assays. 100% concordance was also observed in all assessments of assay precision when appropriate QC metrics were applied. CONCLUSIONS: Significant development time was required to optimize sample preparation and instrumental analysis and 3 assays were removed due to inconsistent performance. Following modification of the manufacturer's protocol and instituting manual review of each assay plate, the Agena PGx74 and custom panel constitute a cost-effective, robust, and accurate method for clinical identification of 106 SNVs involved in drug response.

Methodological quality of clinical practice guidelines for genetic testing in children: A systematic assessment using the appraisal of guidelines for research and evaluation II instrument.

Genetic testing of children is faced with numerous problems. High-quality clinical practice guidelines (CPGs) are needed to ensure its safe, and appropriate use. This study aimed to systematically identify the current CPGs for genetic testing in children, and to assess the methodological quality of these CPGs.We searched 6 databases, 3 guideline clearinghouses, and 9 web sites of relevant academic agencies from inception to February 2019. CPGs focused on genetic testing in children were included. Four reviewers independently appraised the quality of the eligible CPGs using the appraisal of guidelines for research, and evaluation (AGREE) II instrument.Seventeen CPGs meeting our inclusion criteria were included. Among them, 16 CPGs were focused on the genetic diagnosis/evaluation of diseases, while only 1 CPG was focused on pharmacogenetics. The median domain scores from highest to lowest were: scope and purpose 80.56% (range: 56.95%-87.50%), clarity of presentation 72.22% (range: 45.83%-88.89%), stakeholder involvement 45.83% (range: 27.78%-55.56%), applicability 31.25% (range: 19.79%-54.17%), rigor of development 21.88%, (range: 13.02%-71.88%), and editorial independence 18.75% (range: 0%-83.33%). According to the overall quality, 6 (35%) CPGs were "not recommended," 8 (47%) CPGs were "recommended with modifications," and only 3 (18%) CPGs were "recommended." The clinical topics of the "recommended" CPGs were warfarin, familial Mediterranean fever, and pediatric pulmonary arterial hypertension.The quality of CPGs for genetic testing in children was generally low, and variable across different CPGs and different AGREE II domains. In future guideline development, more attention should be paid to the aspects of stakeholder involvement, rigor of development, applicability, and editorial independence. Not only will guideline users benefit from our results when determining whether to adopt related CPGs to guide genetic testing in children, but guideline developers could also take into account our results to improve the quality of future CPGs.

Community assessment to advance computational prediction of cancer drug combinations in a pharmacogenomic screen.

The effectiveness of most cancer targeted therapies is short-lived. Tumors often develop resistance that might be overcome with drug combinations. However, the number of possible combinations is vast, necessitating data-driven approaches to find optimal patient-specific treatments. Here we report AstraZeneca's large drug combination dataset, consisting of 11,576 experiments from 910 combinations across 85 molecularly characterized cancer cell lines, and results of a DREAM Challenge to evaluate computational strategies for predicting synergistic drug pairs and biomarkers. 160 teams participated to provide a comprehensive methodological development and benchmarking. Winning methods incorporate prior knowledge of drug-target interactions. Synergy is predicted with an accuracy matching biological replicates for >60% of combinations. However, 20% of drug combinations are poorly predicted by all methods. Genomic rationale for synergy predictions are identified, including ADAM17 inhibitor antagonism when combined with PIK3CB/D inhibition contrasting to synergy when combined with other PI3K-pathway inhibitors in PIK3CA mutant cells.

On the readiness of physicians for pharmacogenomics testing: an empirical assessment.

This paper aims to explore the determinants of adoption of pharmacogenomics (PGx) testing by clinicians, and to assess whether this adoption differs with regard to area of specialization. Data were collected from a web-based survey among physicians in Québec (Canada). Our results highlighted that they perceived several benefits and had favorable attitudes toward PGx tests, but felt unprepared to use them. Results also show that practice specialties matter. Notably, being a family physician decreases the likelihood of adopting PGx tests. This might be explained by the fact that they perceived fewer benefits, used fewer sources of information, and received less training in PGx than their colleagues in other specialties. This is of particular concern given that family physicians are at the forefront of the healthcare system. Overcoming two knowledge barriers, that is, lack of information and clinical guidelines on PGx tests, might enhance physicians' readiness to adopt PGx testing.

Role of pharmacogenetics in public health and clinical health care: a SWOT analysis.

Pharmacogenomics has been lauded as an important innovation in clinical medicine as a result of advances in genomic science. As one of the cornerstones in precision medicine, the vision to determine the right medication in the right dosage for the right treatment with the use of genetic information has not exactly materialised, and few genetic tests have been implemented as the standard of care in health systems worldwide. Here we review the findings from a SWOT analysis to examine the strengths, weaknesses, opportunities and threats around the role of pharmacogenetics in public health and clinical health care, at the micro, meso and macro levels corresponding to the perspectives of the individuals (scientists, patients and physicians), the health-care institutions and the health systems, respectively.

Improving clinical trial sampling for future research - an international approach: outcomes and next steps from the DIA future use sampling workshop 2011.

Clinical trial samples collected for pharmacogenomic and future research are vital resources for the development of safe and effective drugs, yet collecting adequate, representative sample sets in global trials is challenging. The Drug Information Association (DIA) sponsored a workshop on future use sampling in September 2011, bringing together experts from regulatory agencies, academia and industry to discuss challenges to future use sample collection and identify actions to improve collection. Several common themes and associated action items emerged, including the need for international guidance on the collection of samples for future research; additional discussion related to coding, scope of research, and return of research results; and additional education about pharmacogenomic/future research and the importance of long-term storage of specimens.

Personalized medicine: potential, barriers and contemporary issues.

Personalized medicine has gained significant attention over the last decade as technologies for understanding biological differences between individuals have advanced dramatically. There are many potential benefits of personalized medicine including minimizing risk of drug toxicity, increasing benefit from drugs used, contributing to the sustainability of the healthcare system and facilitating drug discovery and development programs. Unfortunately there are also many barriers such as cost, complexity, high quality evidence requirements, and the need for further education that have limited the clinical translation of pharmacogenomic tests to date. Issues that need to be clarified are also considered, such as the regulatory evidence requirements for pharmacogenomic tests and the need for multiple pathways and for pharmacogenomic marker development. These issues surrounding personalized medicine are contextualized using three contemporary examples of pharmacogenetic tests involving drug metabolising enzymes: UDP glucuronosyltransferase 1A1 and irinotecan toxicity, cytochrome P450 2C19 and clopidogrel efficacy, and cytochrome P450 2C9 and warfarin dosing.

Personalized medicine: is it a pharmacogenetic mirage?

The notion of personalized medicine has developed from the application of the discipline of pharmacogenetics to clinical medicine. Although the clinical relevance of genetically-determined inter-individual differences in pharmacokinetics is poorly understood, and the genotype-phenotype association data on clinical outcomes often inconsistent, officially approved drug labels frequently include pharmacogenetic information concerning the safety and/or efficacy of a number of drugs and refer to the availability of the pharmacogenetic test concerned. Regulatory authorities differ in their approach to these issues. Evidence emerging subsequently has generally revealed the pharmacogenetic information included in the label to be premature. Revised drugs labels, together with a flurry of other collateral activities, have raised public expectations of personalized medicine, promoted as 'the right drug at the right dose the first time.' These expectations place the prescribing physician in a dilemma and at risk of litigation, especially when evidence-based information on genotype-related dosing schedules is to all intent and purposes non-existent and guidelines, intended to improve the clinical utility of available pharmacogenetic information or tests, distance themselves from any responsibility. Lack of efficacy or an adverse drug reaction is frequently related to non-genetic factors. Phenoconversion, arising from drug interactions, poses another often neglected challenge to any potential success of personalized medicine by mimicking genetically-determined enzyme deficiency. A more realistic promotion of personalized medicine should acknowledge current limitations and emphasize that pharmacogenetic testing can only improve the likelihood of diminishing a specific toxic effect or increasing the likelihood of a beneficial effect and that application of pharmacogenetics to clinical medicine cannot adequately predict drug response in individual patients.

Pharmacogenetics and rational drug use around the world.

The WHO embraces evidence-based medicine to formulate an essential medicines list (EML) considering disease prevalence, drug efficacy, drug safety and cost-effectiveness. The EML is used by developing countries to build a national formulary. As pharmacogenetics in developed countries evolves, the Pharmacogenetics for Every Nation Initiative (PGENI) convened with representatives from China, Mexico, Ghana and South Africa in August 2009 to evaluate the use of human pharmacogenetics to enhance global drug use policy. The diseases causing mortality, the lack of integration of pharmacovigilance at the national formulary level, the pharmacogenetics research agenda and pharmacogenetics clinician education did not differ greatly among the countries. While there are many unanswered questions, systematically incorporating pharmacogenetics at the national formulary level promises to improve global drug use.

Methodological quality in pharmacogenetic studies with binary assessment of treatment response: a review.

OBJECTIVE: To evaluate the reporting of critical design issues and methods of statistical analysis in pharmacogenetic studies published in the medical literature. STUDY DESIGN AND SETTINGS: Systematic review of 65 original pharmacogenetic studies published in the literature over the last 15 years. RESULTS: The sample size determination and the planned sample size were lacking in 63 papers. The study design characterization was lacking in 43 papers. The number of patients analyzed ranged from 36 to 1400 (median=161 and interquartile range of 119-250). The Pearson's χ2 test and the Fisher's test were the most common forms of analysis. Multiple statistical testing was relevant to 59 papers, but only 11 addressed the issue of multiplicity (Bonferroni correction). Sources of multiplicity were multiple association assessment (45 papers), analysis of both genotype and allelic frequencies (44), and multiple analysis methods (unadjusted and adjusted). Hardy-Weinberg equilibrium was tested in 12 of 45 papers performing allelic analysis and was fully reported in four of them. The results of association analyses were commonly reported as P values but rarely as estimates of an association measure (odds ratio or relative risk) and its accuracy. CONCLUSIONS: These results show that there is considerable room for improvement in the current standards of design, analysis, and reporting of pharmacogenetic research.

Learning from product labels and label changes: how to build pharmacogenomics into drug-development programs.

The 2010 US FDA-Drug Industry Association (DIA) Pharmacogenomics (PGx) Workshop follows a series that began in 2002 bringing together multidisciplinary experts spanning regulatory authorities, medical research, healthcare and industry. This report summarizes the 'Building PGx into Labels' sessions from the workshop, which discussed the critical elements in developing PGx outcomes leading to product labels that inform efficacy and/or safety. Examples were drawn from US prescribing information, which integrated PGx knowledge into medical decisions (e.g., panitumumab, warfarin and clopidogrel). Attendees indicated the need for broader dialog and for guidelines on evidentiary considerations for PGx to be included into product labels. Also discussed was the understanding of appropriate PGx placement on labels; how to encourage adoption by medical communities of label recommendations on PGx tests; and, given the global nature of drug development, worldwide considerations including European Summary of Product Characteristics.

Designing pharmacogenomic studies to be fit for purpose.

The 2010 US FDA-Drug Industry Association (DIA) Pharmacogenomics Workshop, the fifth in a series of meetings that begun in 2002, brought together multidisciplinary experts from regulatory authorities, medical research, healthcare and drug development. This article summarizes the 'Designing Pharmacogenomic Studies to be Fit for Purpose' track in which considerations regarding the use of retrospective and prospective studies were examined in relation to their ability to influence treatment decisions and labeling for drugs. The aim of the session, using real-world examples (KRAS/panitumumab and HLA-B*5701/abacavir), was to identify good scientific principles that would guide the design of studies to identify subgroups of responders during development programs (including marketed drugs), which could subsequently be used to guide treatment decisions.

Compilation of a comprehensive gene panel for systematic assessment of genes that govern an individual's drug responses.

AIMS: Polymorphisms of genes involved in the pharmacokinetic and pharmacodynamic processes underlie the divergent drug responses among individuals. Despite some successes in identifying these polymorphisms, the candidate gene approach suffers from insufficient gene coverage whereas the genome-wide association approach is limited by less than ideal coverage of SNPs in some important genes. To expand the potential of the candidate approach, we aim to delineate a comprehensive network of drug-response genes for in-depth genetic studies. MATERIALS & METHODS: Pharmacologically important genes were extracted from various sources including literatures and web resources. These genes, along with their homologs and regulatory miRNAs, were organized based on their pharmacological functions and weighted by literature evidence and confidence levels. Their coverage was evaluated by analyzing three commercial SNP chips commonly used for genome-wide association studies: Affymetrix SNP array 6.0, Illumina HumanHap1M and Illumina Omni. RESULTS: A panel of drug-response genes was constructed, which contains 923 pharmacokinetic genes, 703 pharmacodynamic genes and 720 miRNAs. There are only 16.7% of these genes whose all known SNPs can be directly or indirectly (r(2) > 0.8) captured by the SNP chips with coverage of more than 80%. This is possibly because these SNPs chips have notably poor performance over rare SNPs and miRNA genes. CONCLUSION: We have compiled a panel of candidate genes that may be pharmacologically important. Using this knowledgebase, we are able to systematically evaluate genes and their variants that govern an individual's response to a given pharmaceutical therapy. This approach can serve as a necessary complement to genome-wide associations.

Drug-diagnostic codevelopment strategies: FDA and industry dialog at the 4th FDA/DIA/PhRMA/PWG/BIO Pharmacogenomics Workshop.

The 4th US FDA/Industry Workshop on Pharmacogenomics in Drug Development and Regulatory Decision Making, was held in MD, USA, on December 10-12, 2007. One of the breakout sessions of the workshop focused on the regulatory issues around codevelopment of drugs and companion diagnostics. This session used hypothetical case studies as focal points for discussion of current thought and critical issues for both industry and the FDA in this evolving field. The panel and the audience discussed the evolution of the FDA's thinking on the regulatory path for companion diagnostics since the release of the April 2005 draft Drug Test Codevelopment Concept Paper and the issues faced by industry in attempting codevelopment efforts. This session provided an opportunity to allow an exchange of ideas between the FDA and industry and to identify critical issues that need further discussion in this important and evolving field.