Pharmacogenetic guided versus standard warfarin dosing for routine clinical care with its pharmacoeconomic impact: a randomized controlled clinical trial.

BACKGROUND: Empirical use of pharmacogenetic test(PGT) is advocated for many drugs, and resource-rich setting hospitals are using the same commonly. The clinical translation of pharmacogenetic tests in terms of cost and clinical utility is yet to be examined in hospitals of low middle income countries (LMICs). AIM: The present study assessed the clinical utility of PGT by comparing the pharmacogenetically(PGT) guided- versus standard of care(SOC)- warfarin therapy, including the health economics of the two warfarin therapies. METHODS: An open-label, randomized, controlled clinical trial recruited warfarin-receiving patients in pharmacogenetically(PGT) guided- versus standard of care(SOC)- study arms. Pharmacogenetic analysis of CYP2C9*2(rs1799853), CYP2C9*3(rs1057910) and VKORC1(rs9923231) was performed for patients recruited to the PGT-guided arm. PT(Prothrombin Time)-INR(international normalized ratio) testing and dose titrations were allowed as per routine clinical practice. The primary endpoint was the percent time spent in the therapeutic INR range(TTR) during the 90-day observation period. Secondary endpoints were time to reach therapeutic INR(TRT), the proportion of adverse events, and economic comparison between two modes of therapy in a Markov model built for the commonest warfarin indication- atrial fibrillation. RESULTS: The study enrolled 168 patients, 84 in each arm. Per-protocol analysis showed a significantly high median time spent in therapeutic INR in the genotype-guided arm(42.85%; CI 21.4-66.75) as compared to the SOC arm(8.8%; CI 0-27.2)(p < 0.00001). The TRT was less in the PG-guided warfarin dosing group than the standard-of-care dosing warfarin group (17.85 vs. 33.92 days) (p = 0.002). Bleeding and thromboembolic events were similar in the two study groups. Lifetime expenditure was ₹1,26,830 in the PGT arm compared to ₹1,17,907 in the SOC arm. The QALY gain did not differ in the two groups(3.9 vs. 3.65). Compared to SOC, the incremental cost-utility ratio was ₹35,962 per QALY gain with PGT test opting. In deterministic and probabilistic sensitivity analysis, the base case results were found to be insensitive to the variation in model parameters. In the cost-effectiveness-acceptability curve analysis, a 90% probability of cost-effectiveness was reached at a willingness-to-pay(WTP) of ₹ 71,630 well below one time GDP threshold of WTP used. CONCLUSION: Clinical efficacy and the cost-effectiveness of the warfarin pharmacogenetic test suggest its routine use as a point of care investigation for patient care in LMICs.

Genetic-guided pharmacotherapy for venous thromboembolism: a systematic and critical review of economic evaluations.

Despite the known contributions of genes, genetic-guided pharmacotherapy has not been routinely implemented for venous thromboembolism (VTE). To examine evidence on cost-effectiveness of genetic-guided pharmacotherapy for VTE, we searched six databases, websites of four HTA agencies and citations, with independent double-reviewers in screening, data extraction, and quality rating. The ten eligible studies, all model-based, examined heterogeneous interventions and comparators. Findings varied widely; testing was cost-saving in two base-cases, cost-effective in four, not cost-effective in three, dominated in one. Of 22 model variables that changed decisions about cost-effectiveness, effectiveness/relative effectiveness of the intervention was the most frequent, albeit of poor quality. Studies consistently lacked details on the provision of interventions and comparators as well as on model development and validation. Besides improving the reporting of interventions, comparators, and methodological details, future economic evaluations should examine strategies recommended in guidelines and testing key model variables for decision uncertainty, to advise clinical implementations.

Providers' perspectives on the clinical utility of pharmacogenomic testing in pediatric patients.

Aim: To assess providers' knowledge, attitudes, perceptions, and experiences related to pharmacogenomic (PGx) testing in pediatric patients. Materials & methods: An electronic survey was sent to multidisciplinary healthcare providers at a pediatric hospital. Results: Of 261 respondents, 71.3% were slightly or not at all familiar with PGx, despite 50.2% reporting prior PGx education or training. Most providers, apart from psychiatry, perceived PGx to be at least moderately useful to inform clinical decisions. However, only 26.4% of providers had recent PGx testing experience. Unfamiliarity with PGx and uncertainty about the clinical value of testing were common perceived challenges. Conclusion: Low PGx familiarity among pediatric providers suggests additional education and electronic resources are needed for PGx examples in which data support testing in children.

Rates of genetic testing in patients prescribed drugs with pharmacogenomic information in FDA-approved labeling.

This study examined rates of genetic testing in two cohorts of publicly insured individuals who have newly prescribed medication with FDA pharmacogenomic labeling guidance. Genetic testing was rare (4.4% and 10.5% in Medicaid and Medicare cohorts, respectively) despite the fact that all participants selected were taking medications that contained pharmacogenomic labeling information. When testing was conducted it was typically done before the initial use of a target medication. Factors that emerged as predictors of the likelihood of undergoing genetic testing included White ethnicity (vs. Black), female gender, and age. Cost analyses indicated higher expenditures in groups receiving genetic testing vs. matched comparators with no genetic testing, as well as disparities between proactively and reactively tested groups (albeit in opposite directions across cohorts). Results are discussed in terms of the possible reasons for the low base rate of testing, mechanisms of increased cost, and barriers to dissemination and implementation of these tests.

Sociodemographic factors and beliefs about medicines in the uptake of pharmacogenomic testing in older adults.

Aim: To assess the impact of sociodemographic factors and beliefs about medicines on the uptake of pharmacogenomic testing in older adults in a public healthcare system. Materials & methods: Data are based on a sample of 347 primary care older adults. Results: Most respondents (90%) were willing to provide a saliva sample and 47% were willing to pay for it. Increased age (odds ratio: 0.91; p = 0.04) and negative beliefs about the harmfulness of medicines (odds ratio: 0.68; p = 0.02) were associated with a decreased willingness to provide a sample. Lower education (less than university, odds ratio: 0.54; p = 0.04) was associated with a decreased willingness to pay. Conclusion: Education and beliefs about medicines are important factors in the acceptability of pharmacogenomic testing in older adults.

Characterizing Pharmacogenetic Testing Among Children's Hospitals.

Although pharmacogenetic testing is becoming increasingly common across medical subspecialties, a broad range of utilization and implementation exists across pediatric centers. Large pediatric institutions that routinely use pharmacogenetics in their patient care have published their practices and experiences; however, minimal data exist regarding the full spectrum of pharmacogenetic implementation among children's hospitals. The primary objective of this nationwide survey was to characterize the availability, concerns, and barriers to pharmacogenetic testing in children's hospitals in the Children's Hospital Association. Initial responses identifying a contact person were received from 18 institutions. Of those 18 institutions, 14 responses (11 complete and 3 partial) to a more detailed survey regarding pharmacogenetic practices were received. The majority of respondents were from urban institutions (72%) and held a Doctor of Pharmacy degree (67%). Among all respondents, the three primary barriers to implementing pharmacogenetic testing identified were test reimbursement, test cost, and money. Conversely, the three least concerning barriers were potential for genetic discrimination, sharing results with family members, and availability of tests in certified laboratories. Low-use sites rated several barriers significantly higher than the high-use sites, including knowledge of pharmacogenetics (P = 0.03), pharmacogenetic interpretations (P = 0.04), and pharmacogenetic-based changes to therapy (P = 0.03). In spite of decreasing costs of pharmacogenetic testing, financial barriers are one of the main barriers perceived by pediatric institutions attempting clinical implementation. Low-use sites may also benefit from education/outreach in order to reduce perceived barriers to implementation.

PARC report: a health-systems focus on reimbursement and patient access to pharmacogenomics testing.

Pharmacogenomics test coverage and reimbursement are major obstacles to clinical uptake. Several early adopter programs have been successfully initiated through dedicated investments by federal and institutional research funding. As a result of research endeavors, evidence has grown sufficiently to support development of pharmacogenomics guidelines. However, clinical uptake is still limited. Third-party payer support plays an important role in increasing adoption, which to date has been limited to reactive single-gene testing. Access to and interest in direct-to-consumer genetic testing are driving demand for increasing healthcare providers and third-party awareness of this burgeoning field. Pharmacogenomics implementation models developed by early adopters promise to expand patient access and options, as testing continues to increase due to growing consumer interest and falling test prices.

PARC report: a perspective on the state of clinical pharmacogenomics testing.

In this Perspective, the authors discuss the state of pharmacogenomics testing addressing a number of advances, challenges and barriers, including legal ramifications, changes to the regulatory landscape, coverage of testing and the implications of direct-to-consumer genetic testing on the provision of care to patients. Patient attitudes toward pharmacogenomics testing and associated costs will play an increasingly important role in test acquisition and subsequent utilization in a clinical setting. Additional key steps needed include: further research trials demonstrating clinical utility and cost-effectiveness of pharmacogenetic testing, evidence review to better integrate genomic information into clinical practice guidelines in target therapeutic areas to help providers identify patients that may benefit from pharmacogenetic testing and engagement with payers to create a path to reimbursement for pharmacogenetic tests that currently have sufficient evidence of clinical utility. Increased adoption of testing by payers and improved reimbursement practices will be needed to overcome barriers, especially as the healthcare landscape continues to shift toward a system of value-based care.

Patients' Perspectives on Psychiatric Pharmacogenetic Testing.

INTRODUCTION: There is growing interest to adopt pharmacogenetic (PGx) testing in psychiatric medicine, despite mixed views regarding its clinical utility. Nevertheless, providers are utilizing PGx testing among patients with mental health disorders. This study sought to assess genotyped patients' perspectives and experiences with psychiatric PGx testing. METHODS: Individual semi-structured interviews were conducted among patients with depression who had undergone psychiatric PGx testing. The audio-recorded interviews were transcribed and analyzed inductively and deductively for salient themes. RESULTS: Twenty patients (100% Caucasian, 60% female, mean age 39±18 years) were interviewed. The majority of the PGx tests were provider-initiated for patients who failed multiple pharmacotherapies (50%) and/or had medication intolerances (45%). Patients' pre-testing expectations ranged from hopefulness to indifference to skepticism. Their post-testing experiences varied from optimism to disappointment, with the perceived value of the test influenced by the results and cost of the test. DISCUSSION: Genotyped patients had mixed perspectives, expectations, and experiences with psychiatric PGx testing. Their perceived value of the test was influenced by the test outcomes and its cost.

Implementation of a pharmacogenomic program in a Brazilian public institution.

This narrative review describes implementation, current status and perspectives of a pharmacogenomic (PGx) program at the Brazilian National Cancer Institute (INCA), targeting the cancer chemotherapeutic drugs - fluoropyrimidines, irinotecan and thiopurines. This initiative, designed as a research project, was supported by a grant from the Brazilian Ministry of Health. A dedicated task force developed standard operational procedures from recruitment of patients to creating PGx reports with dosing recommendations, which were successfully applied to test 100 gastrointestinal cancer INCA outpatients and 162 acute lymphoblastic leukemia pediatric patients from INCA and seven other hospitals. The program has been subsequently expanded to include gastrointestinal cancer patients from three additional cancer treatment centers. We anticipate implementation of routine pre-emptive PGx testing at INCA but acknowledge challenges associated with this transition, such as continuous financing support, availability of trained personnel, adoption of the PGx-informed prescription by the clinical staff and, ultimately, evidence of cost-effectiveness.

Cost-effectiveness of combinatorial pharmacogenomic testing for depression from the Canadian public payer perspective.

Aim: Evaluate the cost-effectiveness of combinatorial pharmacogenomic (PGx) testing, versus treatment as usual (TAU), to guide treatment for patients with depression, from the Canadian public healthcare system perspective. Materials & methods: Clinical and economic data associated with depression were extracted from published literature. Clinical (quality-adjusted life years; QALYs) and economic (incremental cost-effectiveness ratio) outcomes were modeled using combinatorial PGx and TAU treatment strategies across a 5-year time horizon. Results: With the combinatorial PGx strategy to guide treatment, patients were projected to gain 0.14-0.19 QALYs versus TAU. Accounting for test price, combinatorial PGx saved CAD $1,687-$3,056 versus TAU. Incremental cost-effectiveness ratios ranged from -$11,861 to -$16,124/QALY gained. Conclusion: Combinatorial PGx testing was more efficacious and less costly compared with the TAU for depression.

Economic Evaluations of CYP2C19 Genotype-Guided Antiplatelet Therapy Compared to the Universal Use of Antiplatelets in Patients With Acute Coronary Syndrome: A Systematic Review.

BACKGROUND AND OBJECTIVES: Clopidogrel is widely used after the percutaneous coronary intervention (PCI) in patients with acute coronary syndrome (ACS) and requires activation by cytochrome P450 (CYP), primarily CYP2C19. Patients with CYP2C19 loss-of-function alleles are at increased risk of major adverse cardiovascular events, while more expensive novel antiplatelet agents (ticagrelor and prasugrel) are unaffected by the CYP2C19 mutations. This systematic review aims to answer the question about whether overall evidence supports the genotype-guided selection of antiplatelet therapy as a cost-effective strategy in post-PCI ACS. METHODS: A systematic literature search of PubMed, EMBASE, EconLit, and PharmGKB was done to identify all the economic evaluations related to genotype-guided therapy compared to the universal use of antiplatelets in ACS patients. Quality of Health Economic Studies tool was used for quality assessment. RESULTS: The search identified 13 articles, where genotype-guided treatment was compared to universal clopidogrel, ticagrelor, and/or prasugrel. Six studies showed that genotype-guided therapy was cost-effective compared to universal clopidogrel, while 5 studies showed that it was dominant. One study specified that genotype-guided with ticagrelor is cost-effective only in both CYP2C19 intermediate and poor metabolizers. Genotype-guided therapy was dominant when compared to universal prasugrel, ticagrelor, or both in 5, 1, and 3 studies, respectively. Only 2 studies reported that universal ticagrelor was cost-effective compared to genotype-guided treatment. All the included articles had good quality. CONCLUSION: Based on current economic evaluations in the literature, implementing CYP2C19 genotype-guided therapy is a cost-effective approach in guiding the selection of medication in patients with ACS undergoing PCI.

Cost-Effectiveness of RAS Genetic Testing Strategies in Patients With Metastatic Colorectal Cancer: A Systematic Review.

BACKGROUND: Monoclonal antibodies against epidermal growth factor receptor (EGFR) have proved beneficial for the treatment of metastatic colorectal cancer (mCRC), particularly when combined with predictive biomarkers of response. International guidelines recommend anti-EGFR therapy only for RAS (NRAS,KRAS) wild-type tumors because tumors with RAS mutations are unlikely to benefit. OBJECTIVES: We aimed to review the cost-effectiveness of RAS testing in mCRC patients before anti-EGFR therapy and to assess how well economic evaluations adhere to guidelines. METHODS: A systematic review of full economic evaluations comparing RAS testing with no testing was performed for articles published in English between 2000 and 2018. Study quality was assessed using the Quality of Health Economic Studies scale, and the British Medical Journal and the Philips checklists. RESULTS: Six economic evaluations (2 cost-effectiveness analyses, 2 cost-utility analyses, and 2 combined cost-effectiveness and cost-utility analyses) were included. All studies were of good quality and adopted the perspective of the healthcare system/payer; accordingly, only direct medical costs were considered. Four studies presented testing strategies with a favorable incremental cost-effectiveness ratio under the National Institute for Clinical Excellence (£20 000-£30 000/QALY) and the US ($50 000-$100 000/QALY) thresholds. CONCLUSIONS: Testing mCRC patients for RAS status and administering EGFR inhibitors only to patients with RAS wild-type tumors is a more cost-effective strategy than treating all patients without testing. The treatment of mCRC is becoming more personalized, which is essential to avoid inappropriate therapy and unnecessarily high healthcare costs. Future economic assessments should take into account other parameters that reflect the real world (eg, NRAS mutation analysis, toxicity of biological agents, genetic test sensitivity and specificity).

Cost-Effectiveness of Multigene Pharmacogenetic Testing in Patients With Acute Coronary Syndrome After Percutaneous Coronary Intervention.

OBJECTIVE: To evaluate the cost-effectiveness of multigene testing (CYP2C19, SLCO1B1, CYP2C9, VKORC1) compared with single-gene testing (CYP2C19) and standard of care (no genotyping) in acute coronary syndrome (ACS) patients undergoing percutaneous coronary intervention (PCI) from Medicare's perspective. METHODS: A hybrid decision tree/Markov model was developed to simulate patients post-PCI for ACS requiring antiplatelet therapy (CYP2C19 to guide antiplatelet selection), statin therapy (SLCO1B1 to guide statin selection), and anticoagulant therapy in those that develop atrial fibrillation (CYP2C9/VKORC1 to guide warfarin dose) over 12 months, 24 months, and lifetime. The primary outcome was cost (2016 US dollar) per quality-adjusted life years (QALYs) gained. Costs and QALYs were discounted at 3% per year. Probabilistic sensitivity analysis (PSA) varied input parameters (event probabilities, prescription costs, event costs, health-state utilities) to estimate changes in the cost per QALY gained. RESULTS: Base-case-discounted results indicated that the cost per QALY gained was $59 876, $33 512, and $3780 at 12 months, 24 months, and lifetime, respectively, for multigene testing compared with standard of care. Single-gene testing was dominated by multigene testing at all time horizons. PSA-discounted results indicated that, at the $50 000/QALY gained willingness-to-pay threshold, multigene testing had the highest probability of cost-effectiveness in the majority of simulations at 24 months (61%) and over the lifetime (81%). CONCLUSIONS: On the basis of projected simulations, multigene testing for Medicare patients post-PCI for ACS has a higher probability of being cost-effective over 24 months and the lifetime compared with single-gene testing and standard of care and could help optimize medication prescribing to improve patient outcomes.

Demand for Precision Medicine: A Discrete-Choice Experiment and External Validation Study.

BACKGROUND: A limited evidence base and lack of clear clinical guidelines challenge healthcare systems' adoption of precision medicine. The effect of these conditions on demand is not understood. OBJECTIVE: This research estimated the public's preferences and demand for precision medicine outcomes. METHODS: A discrete-choice experiment survey was conducted with an online sample of the US public who had recent healthcare experience. Statistical analysis was undertaken using an error components mixed logit model. The responsiveness of demand in the context of a changing evidence base was estimated through the price elasticity of demand. External validation was examined using real-world demand for the 21-gene recurrence score assay for breast cancer. RESULTS: In total, 1124 (of 1849) individuals completed the web-based survey. The most important outcomes were survival gains with statistical uncertainty, cost of testing, and medical expert agreement on changing care based on test results. The value ($US, year 2017 values) for a test where most (vs. few) experts agreed to changing treatment based on test results was $US1100 (95% confidence interval [CI] 916-1286). Respondents were willing to pay $US265 (95% CI 46-486) for a test that could result in greater certainty around life-expectancy gains. The predicted demand of the assay was 9% in 2005 and 66% in 2014, compared with real-world uptake of 7% and 71% (root-mean-square prediction error 0.11). Demand was sensitive to price (1% increase in price resulted in > 1% change in demand) when first introduced and insensitive to price (1% increase in price resulted in < 0.1% change in demand) as the evidence base became established. CONCLUSIONS: Evidence of external validity was found. Demand was weak and responsive to price in the near term because of uncertainty and an immature evidence base. Clear communication of precision medicine outcomes and uncertainty is crucial in allowing healthcare to align with individual preferences.

Economic Outcomes Following Combinatorial Pharmacogenomic Testing for Elderly Psychiatric Patients.

OBJECTIVE: We compared economic outcomes when elderly patients with neuropsychiatric disorders received psychotropic medications guided by a combinatorial pharmacogenomic (PGx) test. METHODS: This is a subanalysis of a 1-year prospective assessment of medication cost for patients with neuropsychiatric disorders receiving combinatorial PGx testing. Pharmacy claims were used to compare per member per year (PMPY) medication cost for patients ≥65 and <65 years old when medications were congruent or incongruent with the PGx test. Polypharmacy was also assessed. RESULTS: Congruent prescribing was associated with savings of US$3497 PMPY (P < .001) for patients ≥65 years and US$2467 PMPY (P < .001) for patients <65, compared to incongruent prescribing. Congruent prescribing in patients ≥65 treated by primary care providers was associated with US$4113 PMPY (P = .026) in savings, while congruent prescribing by psychiatrists was associated with US$120 PMPY (P = .719). Congruent prescribing was also associated with one fewer neuropsychiatric medication for patients ≥65 (P = .070). CONCLUSION: Congruence with PGx testing was associated with medication cost savings in elderly patients.

Stakeholder perspectives of the clinical utility of pharmacogenomic testing in solid organ transplantation.

Aims: To assess stakeholder perspectives regarding the clinical utility of pharmacogenomic (PGx) testing following kidney, liver, and heart transplantation. Methods: We conducted individual semi-structured interviews and focus groups with kidney, liver, and heart transplantation patients and providers. We analyzed the qualitative data to identify salient themes. Results: The study enrolled 36 patients and 24 providers. Patients lacked an understanding about PGx, but expressed interest in PGx testing. Providers expressed willingness to use PGx testing, but reported barriers to implementation, such as lack of knowledge, lack of evidence demonstrating clinical utility, and patient healthcare burden. Conclusion: Patient and provider educational efforts, including foundational knowledge, clinical evidence, and applications to patient care beyond just immunosuppression, may be useful to facilitate the use of PGx testing in transplant medicine.

Are There Different Evidence Thresholds for Genomic Versus Clinical Precision Medicine? A Value of Information-Based Framework Applied to Antiplatelet Drug Therapy.

BACKGROUND: The threshold of sufficient evidence for adoption of clinically- and genomically-guided precision medicine (PM) has been unclear. OBJECTIVE: To evaluate evidence thresholds for clinically guided PM versus genomically guided PM. METHODS: We develop an "evidence threshold criterion" (ETC), which is the time-weighted difference between expected value of perfect information and incremental net health benefit minus the cost of research, and use it as a measure of evidence threshold that is proportional to the upper bound of disutility to a risk-averse decision maker for adopting a new intervention under decision uncertainty. A larger (more negative) ETC value indicates that only decision makers with low risk aversion would adopt new intervention. We evaluated the ETC plus cost of research (ETCc), assuming the same cost of research for both interventions, over time for a pharmacogenomic (PGx) testing intervention and avoidance of a drug-drug interaction (aDDI) intervention for acute coronary syndrome patients indicated for antiplatelet therapy. We then examined how the ETC may explain incongruous decision making across different national decision-making bodies. RESULTS: The ETCc for PGx increased over time, whereas the ETCc for aDDI decreased to a negative value over time, indicating that decision makers with even low risk aversion will have doubts in adopting PGx, whereas decision makers who are highly risk-averse will continue to have doubts about adopting aDDI. National recommendation bodies appear to be consistent over time within their own decision making, but had different levels of risk aversion. CONCLUSION: The ETC may be a useful metric for assessing policy makers' risk preferences and, in particular, understanding differences in policy recommendations for genomic versus clinical PM.