Ancillary risk information and pharmacogenetic tests: social and policy implications

Revisiting Secondary Information Related to Pharmacogenetic Testing

Incidental or secondary findings have been a major part of the discussion of genomic medicine research and clinical applications. For pharmacogenetic (PGx) testing, secondary findings arise due to the pleiotropic effects of pharmacogenes, often related to their endogenous functions. Unlike the guidelines that have been developed for whole exome or genome sequencing applications for management of secondary findings (though slightly different from PGx testing in that these refer to detection of variants in multiple genes, some with clinical significance and actionability), no corresponding guidelines have been developed for PGx clinical laboratories. Nonetheless, patient and provider education will remain key components of any PGx testing program to minimize adverse responses related to secondary findings.

Clinical Pharmacogenetics for Precision Medicine: Successes and Setbacks

BACKGROUND

Pharmacogenetics is a key component in the delivery of therapeutics to maximize pharmacologic efficacy and minimize toxicity. There are numerous identified gene-drug pairs that demonstrate the utility of pharmacogenetics testing for drug or dose selection. Although some of these pairs have translated into clinical use, pharmacogenetic testing has not yet made its way into routine clinical practice at many institutions.

CONTENT

This review provides an overview of clinically actionable pharmacogenetics in precision medicine. Examples of successfully implemented gene-drug pairs, along with common testing methodologies and guidelines for application, are discussed. Remaining barriers to widespread clinical implementation are also examined.

SUMMARY

There is a recognized role for genotyping in the guidance of therapeutic drug regimens and the prevention of adverse drug reactions. Evidence-based guidelines are available to aid in the selection of treatment upon pharmacogenetics testing for established gene-drug pairs. Multidisciplinary clinical collaboration and clinical decision support tools will be critical for widespread adoption, and financial reimbursement barriers remain.

Disclosing Pleiotropic Effects During Genetic Risk Assessment for Alzheimer Disease: A Randomized Trial

BACKGROUND

Increasing use of genetic testing raises questions about disclosing secondary findings, including pleiotropic information.

OBJECTIVE

To determine the safety and behavioral effect of disclosing modest associations between apolipoprotein E (APOE) genotype and coronary artery disease (CAD) risk during APOE-based genetic risk assessments for Alzheimer disease (AD).

DESIGN

Randomized, multicenter equivalence clinical trial. (ClinicalTrials.gov: NCT00462917).

SETTING

4 teaching hospitals.

PARTICIPANTS

257 asymptomatic adults were enrolled, 69% of whom had 1 AD-affected first-degree relative.

INTERVENTION

Disclosure of genetic risk information about AD and CAD (AD+CAD) or AD only (AD-only).

MEASUREMENTS

Primary outcomes were Beck Anxiety Inventory (BAI) and Center for Epidemiologic Studies Depression Scale (CES-D) scores at 12 months. Secondary outcomes were all measures at 6 weeks and 6 months and test-related distress and health behavior changes at 12 months.

RESULTS

At 12 months, mean BAI scores were 3.5 in both the AD-only and AD+CAD groups (difference, 0.0 [95% CI, -1.0 to 1.0]), and mean CES-D scores were 6.4 and 7.1 in the AD-only and AD+CAD groups, respectively (difference, 0.7 [CI, -1.0 to 2.4]). Both confidence bounds fell within the equivalence margin of ±5 points. Among carriers of the APOE ε4 allele, distress was lower in the AD+CAD groups (difference, -4.8 [CI, -8.6 to -1.0]) (P = 0.031 for the interaction between group and APOE genotype). Participants in the AD+CAD groups also reported more health behavior changes, regardless of APOE genotype.

LIMITATIONS

Outcomes were self-reported by volunteers without severe anxiety, severe depression, or cognitive problems. Analyses omitted 33 randomly assigned participants.

CONCLUSION

Disclosure of pleiotropic information did not increase anxiety or depression and may have decreased distress among persons at increased risk for 2 conditions. Providing risk modification information about CAD improved health behaviors. Findings highlight the potential benefits of disclosure of secondary genetic findings when options exist for decreasing risk.

PRIMARY FUNDING SOURCE

National Human Genome Research Institute.

Pharmacogenomics--how close/far are we to practising individualized medicine for children?

The translation of pharmacogenomics into clinical practice is a key approach for practising individualized medicine, which aims to maximize drug efficacy and minimize drug toxicity. Since the completion of both the Human Genome Project and the International HapMap project, the development of pharmacogenomics has been greatly facilitated. However, progress in translating pharmacogenomics into clinical practice, especially in paediatric medicine, is unexpectedly slow. Many challenges from different areas remain. This paper discusses the existing applications and the limitations to the implementation of paediatric pharmacogenomics, as well as possible solutions for overcoming these limitations and challenges.

Personalized sequencing and the future of medicine: discovery, diagnosis and defeat of disease

The potential for personalized sequencing to individually optimize medical treatment in diseases such as cancer and for pharmacogenomic application is just beginning to be realized, and the utility of sequencing healthy individuals for managing health is also being explored. The data produced requires additional advancements in interpretation of variants of unknown significance to maximize clinical benefit. Nevertheless, personalized sequencing, only recently applied to clinical medicine, has already been broadly applied to the discovery and study of disease. It is poised to enable the earlier and more accurate diagnosis of disease risk and occurrence, guide prevention and individualized intervention as well as facilitate monitoring of healthy and treated patients, and play a role in the prevention and recurrence of future disease. This article documents the advancing capacity of personalized sequencing, reviews its impact on disease-oriented scientific discovery and anticipates its role in the future of medicine.

Understanding patient and provider perceptions and expectations of genomic medicine

Advances in genome sequencing technology have fostered a new era of clinical genomic medicine. Genetic counselors, who have begun to support patients undergoing multi-gene panel testing for hereditary cancer risk, will review brief clinical vignettes, and discuss early experiences with clinical genomic testing. Their experiences will frame a discussion about how current testing may challenge patient understanding and expectations toward the evaluation of cancer risk and downstream preventive behaviors.

Comparison of delivery strategies for pharmacogenetic testing services

The number and use of pharmacogenetic tests to assess a patient's likelihood of response or risk of an adverse event is expanding across medical specialties and becoming more prevalent. During this period of development and translation, different approaches are being investigated to optimize delivery of pharmacogenetic services. In this paper, we review pre-emptive and point-of-care delivery approaches currently implemented or being investigated and discuss the advantages and disadvantages of each approach. The continued growth in knowledge about the genetic basis of drug response combined with development of new and less expensive testing technologies and electronic medical records will impact future delivery systems. Regardless of delivery approach, the currently limited knowledge of health professionals about genetics generally or PGx specifically will remain a major obstacle to utilization.

Delivering pharmacogenetic testing in a primary care setting

Pharmacogenetic testing refers to a type of genetic test to predict a patient’s likelihood to experience an adverse event or not respond to a given drug. Despite revision to several labels of commonly prescribed drugs regarding the impact of genetic variation, the use of this testing has been limited in many settings due to a number of factors. In the primary care setting, the limited office time as well as the limited knowledge and experience of primary care practitioners have likely attributed to the slow uptake of pharmacogenetic testing. This paper provides talking points for primary care physicians to discuss with patients when pharmacogenetic testing is warranted. As patients and physicians become more familiar and accepting of pharmacogenetic testing, it is anticipated that discussion time will be comparable to that of other clinical tests.

Clinical delivery of pharmacogenetic testing services: a proposed partnership between genetic counselors and pharmacists

One of the basic questions in the early uses of pharmacogenetic (PGx) testing revolves around the clinical delivery of testing. Because multiple health professionals may play a role in the delivery of PGx testing, various clinical delivery models have begun to be studied. We propose that a partnership between genetic counselors and pharmacists can assist clinicians in the delivery of comprehensive PGx services. Based on their expert knowledge of pharmacokinetics and pharmacodynamics, pharmacists can facilitate the appropriate application of PGx test results to adjust medication use as warranted and act as a liaison to the healthcare team recommending changes in medication based on test results and patient input. Genetic counselors are well-trained in genetics as well as risk communication and counseling methodology, but have limited knowledge of pharmaceuticals. The complementary knowledge and skill set supports the partnership between genetic counselors and pharmacists to provide effective PGx testing services.

A closer look at the recommended criteria for disclosing genetic results: perspectives of medical genetic specialists, genomic researchers, and institutional review board chairs

Next generation sequencing offers benefit of improved health through knowledge, but comes with challenges, such as inevitable incidental findings (IFs). The applicability of recommended criteria for disclosure of individual results when applied to disclosure of IFs is not well known. The purpose of this study was to examine how medical genetic specialists, genomic researchers, and Institutional Review Board (IRB) chairs perceive the importance of recommended criteria when applied to genetic/genomic IFs. We conducted telephone interviews with medical genetic specialists (genetic counselors, genetic nurses, medical geneticists, laboratory professionals), genomic researchers, and IRB chairs (N = 103). Respondents rated and discussed the importance of nine recommended criteria regarding disclosure of genetic/genomic IFs. Stakeholders agreed the most important criteria for disclosure were: (1) the IF points to a life-threatening condition; (2) there is a treatment; (3) individuals indicate in writing they wanted to be informed of IFs. Criteria rated less important were: analytic validity, high penetrance, association with a young age of onset and relative risk more than 2.0. Respondents indicated that some technical criteria were confusing, and in need of context. Our findings suggest that development of guidelines regarding management of IF include multiple stakeholders' perspectives and be based on a common language.

Genetics specialists' perspectives on disclosure of genomic incidental findings in the clinical setting

OBJECTIVE

Evidence documenting management of incidental findings (IFs) from clinical genomic testing is limited. The aim of this study was to examine genetics specialists' perspectives regarding current and preferred disclosure of clinical genomic IFs.

METHODS

50 genetics specialists, including medical geneticists, laboratory professionals, genetic counselors, and nurses participated in structured telephone interviews. Data were analyzed using qualitative content analysis and descriptive statistics.

RESULTS

Most specialists had encountered IFs, but definitions of IFs varied. They discussed challenges with informing patients about the prospect of IFs and disclosing IFs to patients. Causing psychological harm to patients was a concern. Participants were divided on whether IFs needed to be clinically significant and/or actionable in order to be disclosed to patients. Creating formal disclosure guidelines was considered useful, but only if they were flexible. Additional counseling, more interdisciplinary communication, maintaining contact with patients, and a centralized database to interpret IFs were also proposed.

CONCLUSION

Genetics specialists offer insights into the challenges of defining IFs, knowing when and how to disclose them, and the potential need for flexible disclosure guidelines.

PRACTICE IMPLICATIONS

Further discussion between practicing genetics specialists is needed to develop consensus on the development of best-practice guidelines for IF management.

Mapping the incidentalome: estimating incidental findings generated through clinical pharmacogenomics testing

PURPOSE

Greater clinical validity and economic feasibility are driving the more widespread use of multiplex genetic technologies in routine clinical care, especially for applications in pharmacogenomics. Empirical data on the numbers and types of incidental findings generated through such testing are needed to develop policies and practices related to their clinical use. Of particular importance are disparities in findings relevant to different ancestry groups.

METHODS

The Pharmacogenomic Resource for Enhanced Decisions in Care and Treatment Resource, or PREDICT, is an institutional program to implement prospective clinical genotyping of 34 pharmacogenomic-related genes to guide drug selection and dosing. We curated 5,566 journal articles to quantify and characterize the incidental, non-pharmacogenomic genotype-phenotype associations that could be generated through this clinical genotyping project.

RESULTS

We identified 372 putative incidental genotype-phenotype associations that might be revealed in patients undergoing clinical genotyping for pharmacogenomic purposes. Of these, 287 associations were supported by at least one study demonstrating an odds ratio ≥2.0 or ≤0.5. Numbers of potentially relevant findings varied widely by ancestry group.

CONCLUSION

Rigorous clinical policies for the clinical management of incidental findings are needed because the sheer number of significant findings could prove overwhelming to health-care institutions, providers, and patients.

Survey of genetic counselors and clinical geneticists' use and attitudes toward pharmacogenetic testing

Pharmacogenetic (PGx) testing aims to improve therapeutic outcomes through tailoring treatment based on a patient's genetic risk for non-response and/or an adverse event. Given their expertise, geneticists could facilitate the use of PGx testing; however, the preparedness and perceived role of the clinical genetics community is unclear. To assess the attitudes, preparedness, and perceived roles of geneticists in the delivery of PGx testing, we conducted a survey of 1500 randomly selected board-certified genetic counselors and clinical geneticists in the United States [response rate: 37.8% (n = 516)]. Twelve percent of genetic counselors and 41% of clinical geneticists indicated that they had ordered or coordinated patient care for PGx testing, a seemingly high proportion at this early stage of adoption. Almost all respondents had some education on pharmacogenetics, although only 28% of counselors and 58% of clinical geneticists indicated they felt well-informed about PGx testing. About half of counselors (52%) and clinical geneticists (46%) felt they would play 'some' role in the delivery of PGx testing; 17 and 19%, respectively, felt that they would play 'no' or 'a little' role. At this early stage of PGx testing, the role of geneticists and genetic counselors is unclear. However, their experience may aid in readying PGx testing and informing delivery strategies into clinical practice.

Public perspectives about pharmacogenetic testing and managing ancillary findings

AIMS

Pharmacogenetic (PGx) tests are intended to improve therapeutic outcomes through predicting a patient's likelihood to respond to or experience an adverse effect from a specific treatment. In addition, PGx testing may also generate ancillary, or incidental, disease information unrelated to the purpose for which the test was ordered. To assess public attitudes toward PGx testing, ancillary disease risk information and related clinical issues, we conducted a series of focus groups.

RESULTS

Forty-five individuals recruited from Durham, NC, participated in four focus groups. Overall, participants were enthusiastic about PGx testing, though expressed concerns about privacy, confidentiality, and psychological harms associated with ancillary information. Focus group participants believed that physicians had a responsibility to disclose ancillary risk information, but were concerned about managing and coping with unexpected disease risk information.

CONCLUSION

We find that participants welcomed the integration of PGx testing into therapeutic decision-making. Public concerns about PGx testing and ancillary information specifically centered on personal implications of learning such additional information, suggesting that patient-provider discussion of the benefits and risks of testing will be necessary until public familiarity with these tests increases.

Public attitudes toward ancillary information revealed by pharmacogenetic testing under limited information conditions

PURPOSE

Pharmacogenetic testing can inform drug dosing and selection by aiding in estimating a patient's genetic risk of adverse response and/or failure to respond. Some pharmacogenetic tests may generate ancillary clinical information unrelated to the drug treatment question for which testing is done-an informational "side effect." We aimed to assess public interest and concerns about pharmacogenetic tests and ancillary information.

METHODS

We conducted a random-digit-dial phone survey of a sample of the US public.

RESULTS

We achieved an overall response rate of 42% (n = 1139). When the potential for ancillary information was presented, 85% (±2.82%) of respondents expressed interest in pharmacogenetic testing, compared with 82% (±3.02%) before discussion of ancillary information. Most respondents (89% ± 2.27%) indicated that physicians should inform patients that a pharmacogenetic test may reveal ancillary risk information before testing is ordered. Respondents' interest in actually learning of the ancillary risk finding significantly differed based on disease severity, availability of an intervention, and test validity, even after adjusting for age, gender, education, and race.

CONCLUSION

Under the limited information conditions presented in the survey, the potential of ancillary information does not negatively impact public interest in pharmacogenetic testing. Interest in learning ancillary information is well aligned with the public's desire to be informed about potential benefits and risks before testing, promoting patient autonomy.

Professional perspectives about pharmacogenetic testing and managing ancillary findings

AIMS

Pharmacogenetic (PGx) tests, intended to inform therapeutic decision making through prediction of patient likelihood to respond to or experience an adverse effect from a specific treatment, may also generate ancillary, or incidental, disease information unrelated to the purpose for which the test was ordered. To assess attitudes toward PGx testing, ancillary disease risk information, and related clinical issues, we conducted a series of focus groups among health professionals.

RESULTS

Twenty-one primary care and genetics professionals from Durham, NC, were recruited to participate in three focus groups (two of primary care professionals [PCPs] and one of geneticists). Overall, interest in PGx testing was positive, though enthusiasm was reserved among PCPs due to concerns about clinical utility, insurance coverage, delay of treatment, and ability to communicate and interpret ancillary disease risk information. Although many PCPs felt an obligation to disclose information about ancillary disease risk, geneticists did not believe that it was always necessary, noting the complexities of genetic risk results such as incomplete penetrance.

CONCLUSION

This pilot study found that health professionals' interest in the use of PGx testing was limited by concerns about the lack of evidence of clinical utility and their ability to interpret and communicate ancillary disease risk information to patients. Additional educational resources, access to genetic specialists, and clear clinical guidelines about the use of PGx testing would greatly facilitate appropriate use of testing.

Informed consent in the context of pharmacogenomic research: ethical considerations

Although the scientific research surrounding pharmacogenomics (PGx) has been relatively plentiful, the ethical research concerning this discipline has developed rather conservatively. Following investigation of the ethical, legal and social issues (ELSI) of PGx research, as well as consulting with key stakeholders, we identified six outstanding ethical issues raised by the informed consent process in PGx research: (1) scope of consent; (2) consent to 'add-on' studies; (3) protection of personal information; (4) commercialization; (5) data sharing; and (6) potential risks stemming from population-based research. In discussing these six areas as well as offering specific considerations, this article offers a solid base from which future practical guidelines for informed consent in PGx research can be constructed. As such, this effort works toward filling the ELSI gap and provides ethical support to the numerous PGx projects undertaken by researchers every year.

Personalized medicine and genomics: challenges and opportunities in assessing effectiveness, cost-effectiveness, and future research priorities

Personalized medicine is health care that tailors interventions to individual variation in risk and treatment response. Although medicine has long strived to achieve this goal, advances in genomics promise to facilitate this process. Relevant to present-day practice is the use of genomic information to classify individuals according to disease susceptibility or expected responsiveness to a pharmacologic treatment and to provide targeted interventions. A symposium at the annual meeting of the Society for Medical Decision Making on 23 October 2007 highlighted the challenges and opportunities posed in translating advances in molecular medicine into clinical practice. A panel of US experts in medical practice, regulatory policy, technology assessment, and the financing and organization of medical innovation was asked to discuss the current state of practice and research on personalized medicine as it relates to their own field. This article reports on the issues raised, discusses potential approaches to meet these challenges, and proposes directions for future work. The case of genetic testing to inform dosing with warfarin, an anticoagulant, is used to illustrate differing perspectives on evidence and decision making for personalized medicine.

Clinical and public health implications of emerging genetic technologies

The clinical utility of many emerging genetic technologies has yet to be established. For many new genetic tests, no practice guidelines are available to help clinicians decide when and how to use them in practice. The clinical and public health implications of new genetic technologies are easiest to evaluate when these tests are compared with other genetic tests, including those already well established in clinical practice. Genetic tests can be divided into different categories based on their intent as follows: (1) to establish a diagnosis (genetic diagnostic tests), (2) to classify disease processes to assist management (gene expression profiling), (3) to predict drug response or side effects (pharmacogenomic tests), and (4) to predict susceptibility to disease (genetic susceptibility testing). As new genetic tests emerge, their translation into practice will depend on their performance based on laboratory standards, but also on their ability to enhance prevention or assist clinicians in diagnosing and treating patients. This article reviews the clinical and public health implications of different types of genetic tests, the evaluation of genetic tests from a public health perspective, and the need for partnership to achieve the potential for benefit of new genetic technologies.

Researchers' perceptions of the ethical implications of pharmacogenomics research with children

BACKGROUND

This paper presents the results of an exploratory qualitative study that assesses Canadian pediatric researchers' perceptions of a pre-selected group of ethical issues raised by pharmacogenomics research with children.

METHODS

As a pilot study, we conducted semi-structured telephone interviews with Canadian pediatric pharmacogenomic researchers. The interviews were guided by the following themes: (1) benefits and risks of inclusion, (2) the consent/assent process, and (3) the return of research results.

RESULTS

Issues about assent, consent, risks and benefits, as well as the communication of results were addressed by the respondents. Some issues, such as the unique vulnerability of children, the long term privacy concerns associated with biobanking, additional core elements that need to be discussed and included in the consent/assent forms, as well as the challenges of communicating research results in a pediatric research were not explicitly identified by the respondents.

CONCLUSION

Further consideration should be given to address the ethical challenges of including children in pharmacogenomics research. This exploratory study indicates that further guidance is needed if children are to be protected and yet benefit from such research.

Nutrigenomics and ethics interface: direct-to-consumer services and commercial aspects

A growing variety and number of genetic tests are advertised and sold directly to consumers (DTC) via the Internet, including nutrigenomic tests and associated products and services. Consumers have more access to genetic information about themselves, but access does not entail certainty about the implications of test results. Potential personal and public health harms and benefits are associated with DTC access to genetic testing services. Early policy responses to direct-to-consumer (DTC) genetic testing often involved calls for bans, and some jurisdictions prohibited DTC genetic tests. Recent policy responses by oversight bodies acknowledge expansion in the range of DTC tests available and suggest that a "one-size-fits-all" regulatory approach is not appropriate for all genetic tests. This review discusses ethical and regulatory aspects of DTC genetic testing, focusing particularly on nutrigenomic tests. We identify policy options for regulating DTC genetic tests, including full or partial prohibitions, enforcement of existing truth-in-advertising laws, and more comprehensive information disclosure about genetic tests. We advocate the latter option as an important means to improve transparency about current evidence on the strengths and limits of gene-disease associations and allow consumers to make informed purchasing decisions in the DTC marketplace.

Pharmacogenetic testing: not as simple as it seems

Pharmacogenetics has the potential to help guide treatment decisions by tailoring appropriate drugs and dosages to patients most likely to benefit. This straightforward clinical goal has led some to suggest that pharmacogenetic testing is free of ethical concerns. However, a number of potential risks and clinical uncertainties arise in considering the use of these new tools in clinical care. We propose a classification of pharmacogenetic tests to identify and prioritize the policy issues that will need to be addressed to ensure appropriate delivery of pharmacogenetic testing. We use the classification framework to consider the benefits and risks associated with ancillary information, timing of testing, and storage and retrieval of pharmacogenetic test results among health professionals. These issues have implications for informed consent and genetic counseling requirements, and for the role of health professionals.