Scientific challenges and implementation barriers to translation of pharmacogenomics in clinical practice

Personalized antiseizure medication therapy in critically ill adult patients

Precision medicine has the potential to have a significant impact on both drug development and patient care. It is crucial to not only provide prompt effective antiseizure treatment for critically ill patients after seizures start but also have a proactive mindset and concentrate on epileptogenesis and the underlying cause of the seizures or seizure disorders. Critical illness presents different treatment issues compared with the ambulatory population, which makes it challenging to choose the best antiseizure medications and to administer them at the right time and at the right dose. Since there is a paucity of information available on antiseizure medication dosing in critically ill patients, therapeutic drug monitoring is a useful tool for defining each patient's personal therapeutic range and assisting clinicians in decision-making. Use of pharmacogenomic information relating to pharmacokinetics, hepatic metabolism, and seizure etiology may improve safety and efficacy by individualizing therapy. Studies evaluating the clinical implementation of pharmacogenomic information at the point-of-care and identification of biomarkers are also needed. These studies may make it possible to avoid adverse drug reactions, maximize drug efficacy, reduce drug-drug interactions, and optimize medications for each individual patient. This review will discuss the available literature and provide future insights on precision medicine use with antiseizure therapy in critically ill adult patients.

Pharmacogenomics in Stroke and Cardiovascular Disease: State of the Art

There is considerable interindividual variability in the response to antiplatelet and anticoagulant therapies, and this variation may be attributable to genetic variants. There has been an increased understanding of the genetic architecture of stroke and cardiovascular disease, which has been driven by advancements in genomic technologies and this has raised the possibility of more targeted pharmaceutical treatments. Pharmacogenetics promises to use a patient's genetic profile to treat those who are more likely to benefit from a particular intervention by selecting the best possible therapy. Although there are numerous studies indicating strong evidence for the effect of specific genotypes on the outcomes of vascular drugs, the adoption of pharmacogenetic testing in clinical practice has been slow. This resistance may stem from sometimes conflicting findings among pharmacogenetic studies, a lack of stroke-specific randomized controlled trials to test the effectiveness of genetically-guided therapies, and the practical and cost-effective implementation of genetic testing within the clinic. Thus, this review provides an overview of the genetic variants that influence the individual responses to aspirin, clopidogrel, warfarin and statins and the different methods for pharmacogenetic testing and guidelines for clinical implementation for stroke patients.

Clinicians' Perspectives on Barriers and Facilitators for the Adoption of Non-Invasive Liver Tests for NAFLD: A Mixed-Method Study

(1) Background: Given the high prevalence of non-alcoholic fatty liver disease (NAFLD) and the limitations of liver biopsies, multiple non-invasive tests (NITs) have been developed to identify non-alcoholic fatty liver disease (NAFLD) patients at-risk of progression. The availability of these new NITs varies from country to country, and little is known about their implementation and adoption in routine clinical practice. This study aims to explore barriers and facilitators that influence the adoption of NAFLD NITs, from healthcare professionals’ perspectives. (2) Methods: A cross-sectional study was performed using an exploratory mixed-methods approach. Twenty-seven clinicians from eight different countries with different specialties filled in our questionnaire. Of those, 16 participated in semi-structured interviews. Qualitative and quantitative data were collected and summarized using the recently published Non-adoption, Abandonment, Scale-up, Spread, and Sustainability (NASSS) framework for new medical technologies in healthcare organizations. (3) Results: Several factors were reported as influencing the uptake of NITs for NAFLD in clinical practice. Among those: insufficient awareness of tests; lack of practical guidelines and evidence for the performance of tests in appropriate patient populations and care settings; and absence of sufficient reimbursement systems were reported as the most important barriers. Other factors, most notably ‘local champions’, proper functional payment systems, and sufficient resources in academic hospitals, were indicated as important facilitating factors. (4) Conclusions: Clinicians see the adoption of NITs for NAFLD as a complex process that is modulated by several factors, such as robust evidence, practical guidelines, a proper payment system, and local champions. Future research could explore perspectives from other stakeholders on the adoption of NITs.

Development of an optimized and generic cost-utility model for analyzing genome-guided treatment data

Economic evaluation is an integral component of informed public health decision-making in personalized medicine. However, performing economic evaluation assessments often requires specialized knowledge, expertise, and significant resources. To this end, developing generic models can significantly assist towards providing the necessary evidence for the cost-effectiveness of genome-guided therapeutic interventions, compared to the traditional drug treatment modalities. Here, we report a generic cost-utility analysis model, developed in R, which encompasses essential economic evaluation steps. Specifically, critical steps towards a comprehensive deterministic and probabilistic sensitivity analysis were incorporated in our model, while also providing an easy-to-use graphical user interface, which allows even non-experts in the field to produce a fully comprehensive cost-utility analysis report. To further demonstrate the model's reproducibility, two sets of data were assessed, one stemming from in-house clinical data and one based on previously published data. By implementing the generic model presented herein, we show that the model produces results in complete concordance with the traditionally performed cost-utility analysis for both datasets. Overall, this work demonstrates the potential of generic models to provide useful economic evidence for personalized medicine interventions.

Appraisal and development of evidence-based clinical decision support to enable perioperative pharmacogenomic application

Variable responses to medications complicates perioperative care. As a potential solution, we evaluated and synthesized pharmacogenomic evidence that may inform anesthesia and pain prescribing to identify clinically actionable drug/gene pairs. Clinical decision-support (CDS) summaries were developed and were evaluated using Appraisal of Guidelines for Research and Evaluation (AGREE) II. We found that 93/180 (51%) of commonly-used perioperative medications had some published pharmacogenomic information, with 18 having actionable evidence: celecoxib/diclofenac/flurbiprofen/ibuprofen/piroxicam/CYP2C9, codeine/oxycodone/tramadol CYP2D6, desflurane/enflurane/halothane/isoflurane/sevoflurane/succinylcholine/RYR1/CACNA1S, diazepam/CYP2C19, phenytoin/CYP2C9, succinylcholine/mivacurium/BCHE, and morphine/OPRM1. Novel CDS summaries were developed for these 18 medications. AGREE II mean ± standard deviation scores were high for Scope and Purpose (95.0 ± 2.8), Rigor of Development (93.2 ± 2.8), Clarity of Presentation (87.3 ± 3.0), and Applicability (86.5 ± 3.7) (maximum score = 100). Overall mean guideline quality score was 6.7 ± 0.2 (maximum score = 7). All summaries were recommended for clinical implementation. A critical mass of pharmacogenomic evidence exists for select medications commonly used in the perioperative setting, warranting prospective examination for clinical utility.

Building an information system to facilitate pharmacogenomics clinical translation with clinical decision support

Pharmacogenomics clinical decision support (PGx-CDS) is an important tool to incorporate PGx information into existing clinical workflows and facilitate PGx clinical translation. However, due to the lack of a computable formalization to represent the primary PGx knowledge, the complexity of genomics information and the lag of current commercial electronic health record (EHR) system for precision medicine, it is difficult to develop computerized PGx-CDS. Therefore, we explored a novel approach to build an information system, named the Pharmacogenomics Clinical Translation Platform (PCTP), for PGx clinical implementation. The PCTP can represent, store, and manage the primary PGx knowledge in a structured and computable format. Moreover, it has the potential to provide various PGx-CDS services and simplify the integration of PGx-CDS into EHRs.

Towards next-generation personalization of tacrolimus treatment: a review on advanced diagnostic and therapeutic approaches

The benefit of personalized medicine is that it allows the customization of drug therapy - maximizing efficacy while avoiding side effects. Genetic polymorphisms are one of the major contributors to interindividual variability. Currently, the only gold standard for applying personalized medicine is dose titration. Because of technological advancements, converting genotypic data into an optimum dose has become easier than in earlier years. However, for many medications, determining a personalized dose may be difficult, leading to a trial-and-error method. On the other hand, the technologically oriented pharmaceutical industry has a plethora of smart drug delivery methods that are underutilized in customized medicine. This article elaborates the genetic polymorphisms of tacrolimus as case study, and extensively covers the diagnostic and therapeutic technologies which aid in the delivery of personalized tacrolimus treatment for better clinical outcomes, thereby providing a new strategy for implementing personalized medicine.

Assessment of the need for pharmacogenomics education among pharmacists in the West Bank of Palestine

BACKGROUND

Pharmacogenomics testing aims to optimise therapy and reduce the inter-individual variation in drug response. One of the major barriers against the implementation of pharmacogenomics testing is the low level of knowledge on the topic.

AIMS

This study aimed to evaluate the need for pharmacogenomics education among pharmacists in the West Bank of Palestine.

METHODS

This study was cross-sectional and included 370 pharmacists, among different cities in the West Bank of Palestine between October and December 2020. The questionnaire consisted of 25 close-ended questions that evaluated the exposure to pharmacogenomics education, attitude toward the role of pharmacogenomics testing in clinical practice and self-capability of pharmacists in pharmacogenomics testing.

RESULTS

It was found that 60% of the respondents disagreed that pharmacogenomics was an integral part of the pharmacy school curriculum and/or experiential education. The vast majority of the respondents (94%) agreed that pharmacists should be required to have some knowledge of pharmacogenomics. The majority of the respondents (88.6%) believe that pharmacogenomics testing will improve pharmacists' ability to more effectively control drug therapy expenditures. However, only 38% of the respondents could identify medications that require pharmacogenomics testing, and only 35.1% could identify reliable sources of information regarding pharmacogenomics for healthcare providers and patients.

CONCLUSION

It is seen from the results of this study that there is a high need to learn about pharmacogenomics testing, which can help the pharmacists make pharmacotherapy decisions. Additionally, current pharmacists have low self-confidence in making decisions depending on the results of pharmacogenomics testing. It is recommended to increase the exposure of pharmacogenomics knowledge by including the subject in courses and workshops in pharmacy school curricula in the West Bank of Palestine.

Applying Next-Generation Sequencing Platforms for Pharmacogenomic Testing in Clinical Practice

Pharmacogenomics (PGx) studies the use of genetic data to optimize drug therapy. Numerous clinical centers have commenced implementing pharmacogenetic tests in clinical routines. Next-generation sequencing (NGS) technologies are emerging as a more comprehensive and time- and cost-effective approach in PGx. This review presents the main considerations for applying NGS in guiding drug treatment in clinical practice. It discusses both the advantages and the challenges of implementing NGS-based tests in PGx. Moreover, the limitations of each NGS platform are revealed, and the solutions for setting up and management of these technologies in clinical practice are addressed.

Discrepancies and similarities in the genome-informed guidance for psychiatric disorders amongst different regulatory bodies and research consortia using next generation sequencing-based clinical pharmacogenomics data

Undoubtedly, pharmacogenomics (PGx) aims in optimizing drug treatment responses whilst also improving the patients' quality of life, either via a reduction of adverse drug reactions and/or an enhancement of drug treatment efficacy. To achieve this, PGx guidance is provided by the two major regulatory bodies in a worldwide level, specifically the U.S. Food and Drug Administration (FDA) and the European Medicine Agency (EMA), and occasionally some research consortia, such as the Clinical Pharmacogenetics Implementation Consortium (CPIC) or the Dutch Pharmacogenomics Working Group (DPWG). However, so far, there is a limited number of studies focusing on the delineation of the similarities and more importantly, the discrepancies in the PGx guidance by the different regulatory bodies and consortia. Herein, we use real-life clinical PGx data to highlight such discrepancies and similarities for genome-guided interventions in psychiatric disorders, thus demonstrating the need for harmonization of the guidelines and recommendations. More precisely, we used the PharmCAT genome-informed drug treatment reports from 304 Greek individuals with psychiatric disorders in order to emphasize on the discrepancies in the PGx guidance/guidelines between FDA vs EMA and CPIC vs DPWG, respectively. For example, CYP2D6-pimozide pair is characterized as 'Testing Required' according to FDA and is accompanied by a DPWG PGx guideline, whilst no EMA or CPIC PGx guidance is found for this drug-gene pair. Moreover, discrepancies are observed regarding the type of PGx guidance for CYP2C19-doxepin pair, with 89 individuals from our study cohort requiring a dose prescribing change based on FDA, whilst only 5 individuals have to receive genome-guided treatment adjustment according to CPIC. To our knowledge, this is the first study, in which discrepancies regarding the type of PGx guidance and the number of actionable drug-gene pairs amongst FDA and EMA, as well as CPIC and DPWG, are brought to light with an emphasis on psychiatric disorders.

Implementation of personalized medicine in a context of moral hazard and uncertainty about treatment efficacy

This paper analyzes the decision of a health authority to implement personalized medicine. We consider a model in which the health authority has three possibilities. It can apply either the same treatment (a standard or a new treatment) to the whole population or implement personalized medicine, i.e., use genetic information to offer the most suitable treatment to each patient. We first characterize the drug reimbursement contract of a firm producing a new treatment with a companion genetic test when the firm can undertake an effort to improve drug quality. Then, we determine the conditions under which personalized medicine should be implemented when this effort is observable and when it is not. Finally, we show how the unobservability of effort affects the conditions under which the health authority implements personalized medicine.

Pharmacogenetic Testing: A Tool for Personalized Drug Therapy Optimization

Pharmacogenomics is a study of how the genome background is associated with drug resistance and how therapy strategy can be modified for a certain person to achieve benefit. The pharmacogenomics (PGx) testing becomes of great opportunity for physicians to make the proper decision regarding each non-trivial patient that does not respond to therapy. Although pharmacogenomics has become of growing interest to the healthcare market during the past five to ten years the exact mechanisms linking the genetic polymorphisms and observable responses to drug therapy are not always clear. Therefore, the success of PGx testing depends on the physician's ability to understand the obtained results in a standardized way for each particular patient. The review aims to lead the reader through the general conception of PGx and related issues of PGx testing efficiency, personal data security, and health safety at a current clinical level.

Utility of human leukocyte antigen-B*58: 01 genotyping and patient outcomes

AIM

Human leukocyte antigen (HLA-B*58:01) allele screening before allopurinol administration is recommended to prevent gene-mediated severe cutaneous adverse reactions (SCARs). The objective of the analysis was to examine the clinical utility and effects of HLA-B*58:01 genotyping on patient's outcomes in a practice setting.

PATIENTS AND METHODS

The electronic medical records covering diagnosis, laboratory results, and prescription dispensing for patients who were newly treated with allopurinol or tested for HLA-B*58:01 were obtained from a large medical organization in Taiwan between 2010 and 2014. The uptake of HLA-B*58:01 testing, incidence of allopurinol-associated SCAR, and changes in urate-lowering agent utilization were assessed.

RESULTS

A total of 17 532 allopurinol new users were identified from 2010 to 2014, and the HLA-B*58:01 test was ordered for 2844 (21.76%) of 13 069 new users when available between 2011 and 2014 in the study. The allopurinol-related SCAR events decreased from 0.21% (22/4460) to 0 (0/2167) after the introduction of HLA-B*58:01 testing, accompanied by a gradual increase from 8% (326/4207) to 31% (674/2167) in genotype testing rate. However, the HLA-B*58:01 testing performed before allopurinol prescription was 60.34%, and ~40% of patients were tested after already taking allopurinol. A shift from allopurinol to other urate-lowering agent regimens appeared among new allopurinol users.

CONCLUSION

HLA-B*58:01 test was associated with the prevention of allopurinol-induced SCAR. The clinical utility of genotype testing may not be consistent with recommendations for testing, and treatment alternatives are a competitive intervention associated with effective implications in a real-world setting.

Unveiling the guidance heterogeneity for genome-informed drug treatment interventions among regulatory bodies and research consortia

Pharmacogenomics and personalized medicine interventions hold promise to optimize drug treatment modalities and hence, improve the quality of life of the patients by minimizing the occurrence of adverse drug reactions and/or maximizing drug treatment efficacy. To this end, proper guidance for accurately prescribing the correct drug at the right dose is empowered by major regulatory bodies, namely the U.S. Food and Drug Administration (FDA) and the European Medicine Agency (EMA), and well-recognized research consortia, like the Clinical Pharmacogenetics Implementation Consortium (CPIC), that propose therapeutic recommendations after the thorough evaluation of the existing scientific evidence base. In this context, the consistency of these recommendations is crucial for smoothly integrating pharmacogenomics into the clinic. Here, we collected all of the important and clinically actionable pharmacogenomics information provided by the aforementioned renowned sources and documented it in order to assess potential similarities and, most importantly, differences. Our data show that the level of concordance regarding the guidance provided for the same drug-gene association pairs varies significantly, despite the fact that it all derives from a single evidence base. In particular, apart from the expected similarities in a number of association pairs, especially the ones related to cancer genomics, there are still major discrepancies that create confusion as to which guidance should be followed in order to properly inform drug prescribing. This regulatory deficiency calls for the fruitful engagement of the regulatory agencies involved with the contribution of other experts engaged in the field of pharmacogenomics in an effort to harmonize the existing arsenal of guidance for genome-informed drug prescription. The achievement of harmonization would in turn expedite bringing personalized medicine closer to clinical fruition.

Integrating Next-Generation Sequencing in the Clinical Pharmacogenomics Workflow

Pharmacogenomics has been recognized as a fundamental tool in the era of personalized medicine with up to 266 drug labels, approved by major regulatory bodies, currently containing pharmacogenomics information. Next-generation sequencing analysis assumes a critical role in personalized medicine, providing a comprehensive profile of an individual's variome, particularly that of clinical relevance, comprising of pathogenic variants and pharmacogenomic biomarkers. Here, we propose a strategy to integrate next-generation sequencing into the current clinical pharmacogenomics workflow from deep resequencing to pharmacogenomics consultation, according to the existing guidelines and recommendations.

Medication Exposure Patterns in Primary Care Patients Prescribed Pharmacogenetically Actionable Opioids

Current approaches to assessing medication exposure fail to capture the complexity of the phenomenon and the context in which it occurs. This study's purpose was to develop a typology of subgroups of patients who share common patterns of medication exposure. To create the typology, we used an exemplar sample of 30 patients in a large public healthcare system who had been prescribed the pharmacogenetically actionable opioids codeine or tramadol. Data related to medication exposure were drawn from large data repositories. Using a person-oriented qualitative approach, eight subgroups of patients who shared common patterns of medication exposure were identified. The subgroups had one of five opioid prescription patterns (i.e., singular, episodic, switching, sustained, multiplex), and one of three types of primary foci of medical care (i.e., pain, comorbidities, both). The findings reveal medication exposure patterns that are dynamic, multidimensional, and complex, and the typology offers an innovative approach to assessing medication exposure.

Drug-Induced Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis Call for Optimum Patient Stratification and Theranostics via Pharmacogenomics

The Global Genomic Medicine Collaborative, a multinational coalition of genomic and policy experts working to implement genomics in clinical care, considers pharmacogenomics to be among the first areas in genomic medicine that can provide guidance in routine clinical practice, by linking genetic variation and drug response. Stevens-Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) are severe life-threatening reactions to medications with a high incidence worldwide. Genomic screening prior to drug administration is a key opportunity and potential paradigm for using genomic medicine to reduce morbidity and mortality and ultimately eliminate one of the most devastating adverse drug reactions. This review focuses on the current understanding of the surveillance, pathogenesis, and treatment of SJS/TEN, including the role of genomics and pharmacogenomics in the etiology, treatment, and eradication of preventable causes of drug-induced SJS/TEN. Gaps, unmet needs, and priorities for future research have been identified for the optimal management of drug-induced SJS/TEN in various ethnic populations. Pharmacogenomics holds great promise for optimal patient stratification and theranostics, yet its clinical implementation needs to be cost-effective and sustainable.

Preemptive pharmacogenetic testing: exploring the knowledge and perspectives of US payers

PURPOSE

Preemptive pharmacogenetic testing aims to optimize medication use by having genetic information at the point of prescribing. Payers’ decisions influence implementation of this technology. We investigated U.S. payers’ knowledge, awareness, and perspectives on preemptive pharmacogenetic testing.

METHODS

A qualitative study was conducted using semi-structured interviews. Participants were screened for eligibility through an online survey. A blended inductive and deductive approach was used to analyze the transcripts. Two authors conducted an iterative reading process to code and categorize the data.

RESULTS

Medical or pharmacy directors from 14 payer organizations covering 122 million U.S. lives were interviewed. Three concept domains and ten dimensions were developed. Key findings include: clinical utility concerns and limited exposure to preemptive germline testing, continued preference for outcomes from randomized controlled trials, interest in guideline development, importance of demonstrating an impact on clinical decision making, concerns of downstream costs and benefit predictability, and the impact of public stakeholders such as the FDA and CMS.

CONCLUSION

Both barriers and potential facilitators exist to developing cohesive reimbursement policy for pharmacogenetics, and there are unique challenges for the preemptive testing model. Prospective outcome studies, more precisely defining target populations, and predictive economic models are important considerations for future research.

Are Evidence Standards Different for Genomic- vs. Clinical-Based Precision Medicine? A Quantitative Analysis of Individualized Warfarin Therapy

Evidence requirements for implementation of precision medicine (PM), whether informed by genomic or clinical data, are not well defined. Evidence requirements are driven by uncertainty and its attendant consequences; these aspects can be quantified by a novel technique in health economics: value of information analysis (VOI). We utilized VOI analysis to compare the evidence levels over time for warfarin dosing based on pharmacogenomic vs. amiodarone-warfarin drug-drug interaction information. The primary outcome was the expected value of perfect information (EVPI), which is an estimate of the upper limit of the societal value of conducting future research. Over the past decade, the EVPI for the pharmacogenomic strategy decreased from $1,550 to $140 vs. $1,220 to $280 per patient for the drug-interaction strategy. Evidence levels thus appear to be higher for pharmacogenomic-guided vs. drug-interaction-guided warfarin dosing. Clinical guidelines and reimbursement policies for warfarin PM could be informed by these findings.

Assessment of patient perceptions of genomic testing to inform pharmacogenomic implementation

OBJECTIVE

Pharmacogenomics seeks to improve prescribing by reducing drug inefficacy/toxicity. However, views of patients during pharmacogenomic-guided care are largely unknown. We sought to understand the attitudes and perceptions of patients in an institutional implementation project and hypothesized that views would differ on the basis of experience with pharmacogenomic-guided care.

METHODS

Two focus groups were conducted - one group included patients who had previously been subjected to broad pharmacogenomic genotyping with results available to physicians (pharmacogenomic group), whereas the other had not been offered genotyping (traditional care). Five domains were explored: (i) experiences with medications/side effects, (ii) understanding of pharmacogenomics, (iii) impact of pharmacogenomics on relationships with healthcare professionals, (iv) scenarios involving pharmacogenomic-guided prescribing, and (v) responses to pharmacogenomic education materials.

RESULTS

Nine pharmacogenomic and 13 traditional care participants were included. Participants in both groups agreed that pharmacogenomics could inform prescribing and help identify problem prescriptions, but expressed concerns over insurance coverage and employment discrimination. Both groups diverged on who should be permitted to access pharmacogenomic results, with some preferring access only for providers with a longstanding relationship, whereas others argued for open access. Notably, traditional care participants showed greater skepticism about how results might be used. Case scenarios and tested educational materials elicited strong desires on the part of patients for physicians to engage participants when considering pharmacogenomic-based prescribing and to utilize shared decision-making.

CONCLUSION

Participants experiencing pharmacogenomic-guided care were more receptive toward pharmacogenomic information being used than traditional care participants. As key stakeholders in implementation, addressing patients' concerns will be important to successfully facilitate clinical dissemination.

Feasibility of clinical pharmacist-led CYP2C19 genotyping for patients receiving non-emergent cardiac catheterization in an integrated health system

OBJECTIVE

To assess the feasibility of clinical pharmacist-led CYP2C19 genotype-guided P2Y12 inhibitor antiplatelet drug therapy recommendations to cardiologists in an outpatient cardiology practice.

METHODS

This was a prospective, open-labeled, single-arm study conducted in an integrated healthcare delivery system between March 1, 2013 and January 23, 2014. Patients requiring non-emergent cardiac catheterization were included. A clinical pharmacist provided interpretation and recommendations from genotyping results. The feasibility of implementing CYP2C19 genotype-guided antiplatelet therapy was assessed by the: 1) percentage of patients approached who consented to CYP2C19 genotyping, 2) percentage of patients with CYP2C19 genotyping results available prior to cardiac catheterization, and 3) percentage of clinical pharmacist CYP2C19 genotype-based antiplatelet recommendations accepted by cardiologists.

RESULTS

Of the 43 patients identified for potential recruitment, 22 of these were eligible for study enrollment and 6 (27%) patients consented and received CYP2C19 genotyping. All patients had genotyping results available prior to catheterization and all clinical pharmacists' antiplatelet therapy recommendations were accepted by the patients' cardiologists. Three patients had the CYP2C19 wild-type (*1/*1) genotype and the clinical pharmacist recommended clopidogrel therapy. CYP2C19 variant genotypes (i.e., *1/*2, *1/*17, and *2/*17) were found in the other three patients; alternative antiplatelet therapy was recommended for the patient with the *1/*2 genotype, while clopidogrel was recommended for those with *1/*17 and *2/*17 genotypes.

CONCLUSION

A relatively small proportion of patients undergoing non-emergent cardiac catheterization consented to pharmacogenetic testing; however, their cardiologists were receptive to clinical pharmacists conducting such testing and providing corresponding pharmacotherapy recommendations. Future studies should identify patient barriers to pharmacogenetic testing.

The Routine Clinical use of Pharmacogenetic Tests: What it Will Require?

Pharmacogenetic testing aims to personalize drug therapy with a view to optimising drug efficacy and minimise toxicity. However, despite the potential benefits, pharmacogenetic testing is mostly confined to specialised medical areas, laboratories and centres. Widespread integration into routine clinical practice has been limited by a complex set of issues including regulatory and reimbursement frameworks, evidence of clinical utility and clinician perspectives, practices and education. Here we assess the current barriers to widespread clinical uptake and identify the key issue necessary to address to accelerate routine testing.

Lessons Learned When Introducing Pharmacogenomic Panel Testing into Clinical Practice

OBJECTIVES

Implementing new programs to support precision medicine in clinical settings is a complex endeavor. We describe challenges and potential solutions based on the Indiana GENomics Implementation: an Opportunity for the Underserved (INGenious) program at Eskenazi Health-one of six sites supported by the Implementing GeNomics In pracTicE network grant of the National Institutes of Health/National Human Genome Research Institute. INGenious is an implementation of a panel of genomic tests.

METHODS

We conducted a descriptive case study of the implementation of this pharmacogenomics program, which has a wide scope (14 genes, 27 medications) and a diverse population (patients who often have multiple chronic illnesses, in a large urban safety-net hospital and its outpatient clinics).

CHALLENGES

We placed the clinical pharmacogenomics implementation challenges into six categories: patient education and engagement in care decision making; clinician education and changes in standards of care; integration of technology into electronic health record systems; translational and implementation sciences in real-world clinical environments; regulatory and reimbursement considerations, and challenges in measuring outcomes. A cross-cutting theme was the need for careful attention to workflow. Our clinical setting, a safety-net health care system, presented some distinctive challenges. Patients often had multiple chronic illnesses and sometimes were taking more than one pharmacogenomics-relevant medication. Reaching patients for recruitment or follow-up was another challenge.

CONCLUSIONS

New, large-scale endeavors in health care are challenging. A description of the challenges that we encountered and the approaches that we adopted to address them may provide insights for those who implement and study innovations in other health care systems.

A physiome interoperability roadmap for personalized drug development

The goal of developing therapies and dosage regimes for characterized subgroups of the general population can be facilitated by the use of simulation models able to incorporate information about inter-individual variability in drug disposition (pharmacokinetics), toxicity and response effect (pharmacodynamics). Such observed variability can have multiple causes at various scales, ranging from gross anatomical differences to differences in genome sequence. Relevant data for many of these aspects, particularly related to molecular assays (known as '-omics'), are available in online resources, but identification and assignment to appropriate model variables and parameters is a significant bottleneck in the model development process. Through its efforts to standardize annotation with consequent increase in data usability, the human physiome project has a vital role in improving productivity in model development and, thus, the development of personalized therapy regimes. Here, we review the current status of personalized medicine in clinical practice, outline some of the challenges that must be overcome in order to expand its applicability, and discuss the relevance of personalized medicine to the more widespread challenges being faced in drug discovery and development. We then review some of (i) the key data resources available for use in model development and (ii) the potential areas where advances made within the physiome modelling community could contribute to physiologically based pharmacokinetic and physiologically based pharmacokinetic/pharmacodynamic modelling in support of personalized drug development. We conclude by proposing a roadmap to further guide the physiome community in its on-going efforts to improve data usability, and integration with modelling efforts in the support of personalized medicine development.

Systematic Development and Validation of a Thin-Layer Densitometric Bioanalytical Method for Estimation of Mangiferin Employing Analytical Quality by Design (AQbD) Approach

The present work aims at the systematic development of a simple, rapid and highly sensitive densitometry-based thin-layer chromatographic method for the quantification of mangiferin in bioanalytical samples. Initially, the quality target method profile was defined and critical analytical attributes (CAAs) earmarked, namely, retardation factor (Rf), peak height, capacity factor, theoretical plates and separation number. Face-centered cubic design was selected for optimization of volume loaded and plate dimensions as the critical method parameters selected from screening studies employing D-optimal and Plackett-Burman design studies, followed by evaluating their effect on the CAAs. The mobile phase containing a mixture of ethyl acetate : acetic acid : formic acid : water in a 7 : 1 : 1 : 1 (v/v/v/v) ratio was finally selected as the optimized solvent for apt chromatographic separation of mangiferin at 262 nm withRf 0.68 ± 0.02 and all other parameters within the acceptance limits. Method validation studies revealed high linearity in the concentration range of 50-800 ng/band for mangiferin. The developed method showed high accuracy, precision, ruggedness, robustness, specificity, sensitivity, selectivity and recovery. In a nutshell, the bioanalytical method for analysis of mangiferin in plasma revealed the presence of well-resolved peaks and high recovery of mangiferin.

Health regulatory communications of well-established safety-related pharmacogenomics associations in six developed countries: an evaluation of alignment

Recommendations on genetic testing are typically conveyed by drug regulatory authorities through drug labels, which are legal requirements for market authorization of drugs. We conducted a cross-sectional study of drug labels focusing on three crucial aspects of regulatory pharmacogenomics communications: (i) intent; (ii) interpretation in the local context; and (iii) implications of the genetic information. Labels of drugs associated with well-established safety-related genetic markers for adverse drug reactions across six developed countries of United States, Canada, United Kingdom, Australia, New Zealand and Singapore were reviewed. We found differing medical advice for genotype-positive HLA-B*15:02, HLA-A*31:01, UGT1A1*28 and CYP2D6 ultra-rapid metabolisers in breastfeeding women. This raises questions on implications to clinical practice between these countries. Varying ways of presenting at-risk population and allele frequencies also raises question in incorporating such information in drug labels. An international guidance addressing these crucial aspects of regulatory pharmacogenomic communications in drug labels is long overdue.

Pharmacogenetic Testing: Application in Mental Health Prescribing

BACKGROUND

Despite extensive scholastic and professional training, medication management in psychiatry is often relegated to trial-and-error prescribing. Pharmacogenetic testing (PGT) may expedite identification of medications with maximal efficacy and minimal side effects by recognizing individual genetic variability in drug response.

OBJECTIVES

This article outlines the background of PGT, explains drug metabolism, and evaluates the impact of PGT.

DESIGN

A review of the literature since 2010 found 42 articles regarding PGT in clinical nursing settings on PubMed and ProQuest.

RESULTS

Despite continuing rises in health care costs, new biotechnology has led to a decrease in the cost of genetic sequencing and application of PGT to practice.

CONCLUSION

As PGT becomes increasingly prevalent, nurses should be knowledgeable of its purpose, possibilities, and potential limitations to provide accurate and up-to-date patient information.

Pharmacogenetics: Using Genetic Information to Guide Drug Therapy

Clinical pharmacogenetics, the use of genetic data to guide drug therapy decisions, is beginning to be used for medications commonly prescribed by family physicians. However, clinicians are largely unfamiliar with principles supporting clinical use of this type of data. For example, genetic variability in the cytochrome P450 2D6 drug metabolizing enzyme can alter the clinical effects of some opioid analgesics (e.g., codeine, tramadol), whereas variability in the CYP2C19 enzyme affects the antiplatelet agent clopidogrel. If testing is performed, patients who are ultrarapid or poor metabolizers of CYP2D6 should avoid codeine use (and possibly tramadol, hydrocodone, and oxycodone) because of the potential for increased toxicity or lack of effectiveness. Patients undergoing percutaneous coronary intervention for acute coronary syndromes who are known to be poor metabolizers of CYP2C19 should consider alternate antiplatelet therapy (e.g., ticagrelor, prasugrel). Some guidelines are available that address appropriate drug therapy changes, and others are in development. Additionally, a number of clinical resources are emerging to support family physicians in the use of pharmacogenetics. When used appropriately, pharmacogenetic testing can be a practical tool to optimize drug therapy and avoid medication adverse effects.

Association of carbamazepine-induced severe cutaneous drug reactions and HLA-B*1502 allele status, and dose and treatment duration in paediatric neurology patients in Singapore

OBJECTIVES

To determine the association between severe cutaneous drug reactions (SCDR), HLA-B*1502 allelism, carbamazepine dose and treatment duration in a Singapore paediatric population.

METHOD

Case-control study of SCDR with carbamazepine and HLA-B*1502. We recruited 32 cases, 5 with Steven Johnson Syndrome/Toxic Epidermolytic Necrolysis (SJS/TEN) (2 Chinese, 3 Malay), 6 with hypersensitivity syndrome (HSS) (5 Chinese, 1 Indian), 11 with minor drug reactions (9 Chinese, 2 Malay) and 10 controls (7 Chinese, 2 Malay, 1 Indian). HLA-B*1502 allelism was assayed. HLA-B*1502 status and the type of drug reaction were compared using univariate analysis. The time-span from treatment onset to reaction and the dose-time to reaction association in the 3 groups were analysed.

RESULTS

HLA-B*1502 was positive in: 5/5 (SJS/TEN), 0/6 (HSS), 1/11 (minor drug reactions) and 1/10 controls. OR for SJS/TEN in HLA-B*1502-positive patients relative to that in HLA-B*1502-negative patients was estimated by exact logistic regression to be 27.20 (95% CI 2.67 to ∞). Median treatment duration (days) until allergic reactions was 12 (range 11-13), 16 (range 10-37) and 11 (range 0-63) for SJS/TEN, HSS and minor drug reactions, respectively. Median dose at onset of reactions was 6.2 mg/kg/day (range 4.6-7.4), 9.8 mg/kg/day (range 7.7-12.2) and 6.7 mg/kg/day (range 3.6-20.0) for the 3 groups, respectively.

CONCLUSIONS

HLA-B*1502 positivity increases the odds of carbamazepine-induced SCDR in Singapore children of Chinese and Malay ethnicity. Adverse drug reactions to carbamazepine occurred within 2 weeks and at low doses.

Clinical implementation of germ line cancer pharmacogenetic variants during the next-generation sequencing era

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