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.

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 Burden of Depression and Associated Resource Use in Manitoba, Canada

OBJECTIVES

To characterize the health-care utilization and economic burden associated with depression in Manitoba, Canada.

METHODS

Patient-level data were retrieved from the Manitoba Centre for Health Policy administrative, clinical, and laboratory databases for the study period of January 1, 1996, through December 31, 2016. Patients were assigned to the depression cohort based on diagnoses recorded in hospitalizations and outpatient physician claims, as well as antidepressant prescription drug claims. A comparison cohort of nondepressed subjects, matched with replacement for age, gender, place of residence (urban vs. rural), and index date, was created. Demographics, comorbidities, intentional self-harm, mortality, health-care utilization, prescription drug utilization, and costs of health-care utilization and social services were compared between depressed patients and matched nondepressed patients, and incidence rate ratios and hazard ratios were reported.

RESULTS

There were 190,065 patients in the depression cohort and 378,177 patients in the nondepression cohort. Comorbidities were 43% more prevalent among depressed patients. Intentional self-harm, all-cause mortality, and suicide mortality were higher among patients with depression than the nondepression cohort. Health-care utilization-including hospitalizations, physician visits, physician-provided psychotherapy, and prescription drugs-was higher in the depression than the nondepression cohort. Mean health-care utilization costs were 3.5 times higher among depressed patients than nondepressed patients ($10,064 and $2,832, respectively). Similarly, mean social services costs were 3 times higher ($1,522 and $510, respectively). Overall, depression adds a total average cost of $8,244 (SD = $40,542) per person per year.

CONCLUSIONS

Depression contributes significantly to health burden and per patient costs in Manitoba, Canada. Extrapolation of the results to the entire Canadian health-care system projects an excess of $12 billion annually in health system spending.

Canadian Medication Cost Savings Associated with Combinatorial Pharmacogenomic Guidance for Psychiatric Medications

Objective

To estimate Canadian pharmacy cost savings associated with psychiatric medication prescribing that is guided by combinatorial pharmacogenomic testing in patients switching or augmenting their psychiatric medication.

Methods

Pharmacy claims data from a United States (US) pharmacy benefit manager were analyzed for 1662 patients who recently augmented or switched to a different antidepressant or antipsychotic medication and underwent combinatorial pharmacogenomic testing. Costs of prescription medications were translated to the Canadian healthcare system by matching drug names and doses using the Ontario Drug Benefit Formulary. One-year costs (2017 CAD) were compared between patients whose clinician prescribed antidepressants or antipsychotics that were consistent (congruent) or inconsistent (incongruent) with the combinatorial pharmacogenomic test recommendations.

Results

Patients whose psychiatric medication treatment was congruent with the combinatorial pharmacogenomic test report saved $1061 CAD per member per year (PMPY) on prescription medication costs relative to patients whose medications were incongruent with their test report (p<0.0001). For patients ages <65 and ≥65, prescription medication costs were $979 and $1178 CAD PMPY lower, respectively, for patients who followed the report recommendations (p=0.0004 and p=0.13). Prescription drug fills from the US pharmacy claims were concordant with the Canadian Formulary; 62% of fills matched at both the drug name and dose strength, 81% matched at drug name, and >99% matched at the therapeutic chapter.

Conclusions

Antidepressant and antipsychotic prescribing that was congruent with combinatorial pharmacogenomic test guidance was associated with significant cost savings on Canadian prescription medications according to the Ontario Drug Benefit Formulary.

Analytical validation of a psychiatric pharmacogenomic test

Aim: The aim of this study was to validate the analytical performance of a combinatorial pharmacogenomics test designed to aid in the appropriate medication selection for neuropsychiatric conditions. Materials & methods: Genomic DNA was isolated from buccal swabs. Twelve genes (65 variants/alleles) associated with psychotropic medication metabolism, side effects, and mechanisms of actions were evaluated by bead array, MALDI-TOF mass spectrometry, and/or capillary electrophoresis methods (GeneSight Psychotropic, Assurex Health, Inc.). Results: The combinatorial pharmacogenomics test has a dynamic range of 2.5–20 ng/μl of input genomic DNA, with comparable performance for all assays included in the test. Both the precision and accuracy of the test were >99.9%, with individual gene components between 99.4 and 100%. Conclusion: This study demonstrates that the combinatorial pharmacogenomics test is robust and reproducible, making it suitable for clinical use.

Pharmacogenetic analysis of opioid dependence treatment dose and dropout rate

BACKGROUND

Currently, no pharmacogenetic tests for selecting an opioid-dependence pharmacotherapy have been approved by the US Food and Drug Administration.

OBJECTIVES

Determine the effects of variants in 11 genes on dropout rate and dose in patients receiving methadone or buprenorphine/naloxone (ClinicalTrials.gov Identifier: NCT00315341).

METHODS

Variants in six pharmacokinetic genes (CYP1A2, CYP2B6, CYP2C19, CYP2C9, CYP2D6, CYP3A4) and five pharmacodynamic genes (HTR2A, OPRM1, ADRA2A, COMT, SLC6A4) were genotyped in samples from a 24-week, randomized, open-label trial of methadone and buprenorphine/naloxone for the treatment of opioid dependence (n = 764; 68.7% male). Genotypes were then used to determine the metabolism phenotype for each pharmacokinetic gene. Phenotypes or genotypes for each gene were analyzed for association with dropout rate and mean dose.

RESULTS

Genotype for 5-HTTLPR in the SLC6A4 gene was nominally associated with dropout rate when the methadone and buprenorphine/naloxone groups were combined. When the most significant variants associated with dropout rate were analyzed using pairwise analyses, SLC6A4 (5-HTTLPR) and COMT (Val158Met; rs4860) had nominally significant associations with dropout rate in methadone patients. None of the genes analyzed in the study was associated with mean dose of methadone or buprenorphine/naloxone.

CONCLUSIONS

This study suggests that functional polymorphisms related to synaptic dopamine or serotonin levels may predict dropout rates during methadone treatment. Patients with the S/S genotype at 5-HTTLPR in SLC6A4 or the Val/Val genotype at Val158Met in COMT may require additional treatment to improve their chances of completing addiction treatment. Replication in other methadone patient populations will be necessary to ensure the validity of these findings.

Combinatorial pharmacogenomic guidance for psychiatric medications reduces overall pharmacy costs in a 1 year prospective evaluation

OBJECTIVES

The objective of this project was to determine pharmacy cost savings and improvement in adherence based on a combinatorial pharmacogenomic test (CPGx ) in patients who had switched or added a new psychiatric medication after having failed monotherapy for their psychiatric disorder.

RESEARCH DESIGN AND METHODS

The prospective project compared 1 year pharmacy claims between a GeneSight CPGx guided cohort and a propensity-matched control group. Patients were project eligible if they augmented or switched to a different antidepressant or antipsychotic medication within the previous 90 days. Following the medication switch or augmentation, pharmacogenomic (PGx) testing was offered to each patient's treating clinician. Pharmacy claims were extracted from the Medco pharmacy claims database for each patient (n = 2168) for 1 year following testing and compared to a 5-to-1 propensity-matched treatment as usual (TAU), standard of care control group (n = 10,880).

MAIN OUTCOME MEASURES

Total pharmacy spend per member per year; adherence.

RESULTS

Patients who received PGx testing saved $1035.60 in total medication costs (both CNS and non-CNS medications) over 1 year compared to the non-tested standard of care cohort (p = 0.007). PGx testing improved adherence compared to standard of care (ΔPDCCPGx = 0.11 vs ΔPDCTAU = -0.01; p < 0.0001). Pharmacy cost savings averaged $2774.53 for patients who were changed to a CPGx congruent medication regimen, compared to those who were not (p < 0.0001).

CONCLUSIONS

PGx testing provides significant 'real world' cost savings, while simultaneously improving adherence in a difficult to treat psychiatric population. Limitations of this study include the lack of therapeutic efficacy follow-up data and possible confounding due to matching only on demographic and psychiatric variables.

A prospective, randomized, double-blind study assessing the clinical impact of integrated pharmacogenomic testing for major depressive disorder

OBJECTIVE

A prospective double-blind randomized control trial (RCT) to evaluate the benefit of a combinatorial, five gene pharmacogenomic test and interpretive report (GeneSight) for the management of psychotropic medications used in the treatment of major depression in an outpatient psychiatric practice.

METHODS

Depressed adult outpatients were randomized to a treatment as usual (TAU, n=25) arm or a pharmacogenomic-informed GeneSight (n=26) arm. Subjects were blinded to their treatment group and depression severity was assessed by blinded study raters. Within two days of enrollment, clinicians of subjects in the guided group received the GeneSight report that categorized each of 26 psychotropic medications within a green, yellow, or red "bin" based on the relationship of each medication to a subject's pharmacokinetic and pharmacodynamic combinatorial gene variant profile. Antidepressant medication changes began within 2 weeks after baseline assessments. Depression severity was assessed by blinded study raters using the HAMD-17, PHQ-9, QIDS-SR, and QIDS-CR administered 4, 6, and 10 weeks after baseline assessment.

RESULTS

Between-group trends were observed with greater than double the likelihood of response and remission in the GeneSight group measured by HAMD-17 at week 10. Mean percent improvement in depressive symptoms on HAMD-17 was higher for the GeneSight group over TAU (30.8% vs 20.7%; p=0.28). TAU subjects who had been prescribed medications at baseline that were contraindicated based on the individual subject's genotype (i.e., red bin) had almost no improvement (0.8%) in depressive symptoms measured by HAMD-17 at week 10, which was far less than the 33.1% improvement (p=0.06) in the pharmacogenomic guided subjects who started on a red bin medication and the 26.4% improvement in GeneSight subjects overall (p=0.08).

CONCLUSIONS

Pharmaco-genomic-guided treatment with GeneSight doubles the likelihood of response in all patients with treatment resistant depression and identifies 30% of patients with severe gene-drug interactions who have the greatest improvement in depressive symptoms when switched to genetically suitable medication regimens.

Whole genome association study of brain-wide imaging phenotypes for identifying quantitative trait loci in MCI and AD: A study of the ADNI cohort

A genome-wide, whole brain approach to investigate genetic effects on neuroimaging phenotypes for identifying quantitative trait loci is described. The Alzheimer's Disease Neuroimaging Initiative 1.5 T MRI and genetic dataset was investigated using voxel-based morphometry (VBM) and FreeSurfer parcellation followed by genome-wide association studies (GWAS). One hundred forty-two measures of grey matter (GM) density, volume, and cortical thickness were extracted from baseline scans. GWAS, using PLINK, were performed on each phenotype using quality-controlled genotype and scan data including 530,992 of 620,903 single nucleotide polymorphisms (SNPs) and 733 of 818 participants (175 AD, 354 amnestic mild cognitive impairment, MCI, and 204 healthy controls, HC). Hierarchical clustering and heat maps were used to analyze the GWAS results and associations are reported at two significance thresholds (p<10(-7) and p<10(-6)). As expected, SNPs in the APOE and TOMM40 genes were confirmed as markers strongly associated with multiple brain regions. Other top SNPs were proximal to the EPHA4, TP63 and NXPH1 genes. Detailed image analyses of rs6463843 (flanking NXPH1) revealed reduced global and regional GM density across diagnostic groups in TT relative to GG homozygotes. Interaction analysis indicated that AD patients homozygous for the T allele showed differential vulnerability to right hippocampal GM density loss. NXPH1 codes for a protein implicated in promotion of adhesion between dendrites and axons, a key factor in synaptic integrity, the loss of which is a hallmark of AD. A genome-wide, whole brain search strategy has the potential to reveal novel candidate genes and loci warranting further investigation and replication.

Voxelwise genome-wide association study (vGWAS)

The structure of the human brain is highly heritable, and is thought to be influenced by many common genetic variants, many of which are currently unknown. Recent advances in neuroimaging and genetics have allowed collection of both highly detailed structural brain scans and genome-wide genotype information. This wealth of information presents a new opportunity to find the genes influencing brain structure. Here we explore the relation between 448,293 single nucleotide polymorphisms in each of 31,622 voxels of the entire brain across 740 elderly subjects (mean age+/-s.d.: 75.52+/-6.82 years; 438 male) including subjects with Alzheimer's disease, Mild Cognitive Impairment, and healthy elderly controls from the Alzheimer's Disease Neuroimaging Initiative (ADNI). We used tensor-based morphometry to measure individual differences in brain structure at the voxel level relative to a study-specific template based on healthy elderly subjects. We then conducted a genome-wide association at each voxel to identify genetic variants of interest. By studying only the most associated variant at each voxel, we developed a novel method to address the multiple comparisons problem and computational burden associated with the unprecedented amount of data. No variant survived the strict significance criterion, but several genes worthy of further exploration were identified, including CSMD2 and CADPS2. These genes have high relevance to brain structure. This is the first voxelwise genome wide association study to our knowledge, and offers a novel method to discover genetic influences on brain structure.

Significant support for DAO as a schizophrenia susceptibility locus: examination of five genes putatively associated with schizophrenia

BACKGROUND

Schizophrenia is a complex psychiatric disorder with a strong genetic component. Past linkage studies have implicated several chromosomal regions in the etiology of schizophrenia. Within these regions, several genes have been identified via candidate gene association studies as strong schizophrenia susceptibility loci, including DAO, DAOA, DISC1, DTNBP1, and RGS4.

METHODS

The present study attempted to replicate these association findings by analyzing a total of 120 markers across these genes in 311 schizophrenia subjects, 140 schizoaffective subjects, and 291 control subjects.

RESULTS

Our study found no association for DAOA and DTNBP1 with schizophrenia. Although no association was seen with DAOA and DTNBP1, several other markers in the other genes resulted in significant association with schizophrenia (p < .05). However, after a conservative Bonferroni correction for multiple testing, only one marker, rs3918346, within DAO remained significant (odds ratio = 1.71, confidence interval = 1.32-2.22, p = 4 x 10(-5)). This significant association was concordant with previous DAO genetic findings.

CONCLUSIONS

Our results significantly support DAO as a susceptibility locus for schizophrenia and offer some support for the implication of both RGS4 and DISC1 in the etiology of schizophrenia. However, we see no evidence to support either DAOA or DTNBP1 as schizophrenia disease loci.

Association of the TSHR gene with Graves' disease: the first disease specific locus

The development of autoimmune thyroid disease (AITD) is associated with autoantibodies directed against the thyroid stimulating hormone receptor (TSHR). Previous studies have failed to demonstrate a consistent association between the TSHR and AITD, or any of its sub-phenotypes. In the present study, we analysed the linkage disequilibrium (LD) structure encompassing the TSHR, to identify LD 'blocks' and SNPs, which capture the majority of intra-block haplotype diversity. The haplotype tagging SNPs, plus all common SNPs reported in previous studies were genotyped in 1,059 AITD Caucasian cases and 971 Caucasian controls. A haplotype, across two LD blocks, showed association (P<1 x 10(-6), OR 1.7) with Graves' disease (GD) but not autoimmune hypothyroidism (AIH). We replicated these findings by genotyping the most associated GD SNP, rs2268458, in a separate UK Caucasian cohort of 1,366 AITD cases and 1,061 controls (GD, P=2 x 10(-6), OR 1.3; AIH, P=NS). These results in two independent Caucasian data sets suggest that the TSHR is the first replicated GD-specific locus meriting further fine mapping and functional analysis to identify the aetiological variants.

Inflammatory bowel disease is linked to 19p13 and associated with ICAM-1

Genome-wide scans have implicated several susceptibility loci, but linkage of 19p13 (IBD6) to Crohn's disease (CD) has not been fully replicated. We report a replication study of IBD6 in a UK Caucasian population. Two hundred eighty-four affected sibling pairs from 234 families were used for the linkage study. Linkage between IBD6 linkage and CD was replicated (LOD score = 1.59). Two candidate genes (DDXL and ICAM-1) within the IBD6 locus were examined in a case/control study with a total of 228 CD and 243 ulcerative colitis (UC) patients and 407 healthy controls. No association to either UC or CD was found in three novel intronic single nucleotide polymorphisms (SNPs) in DDXL. For ICAM-1, a significant association was found between K469 homozygosity and CD overall (39.9% vs 29.4%; Pc = 0.0096) and between E469 and fistulating disease (21.8% vs 10.0%, Pc = 0.030). In the UC group, limited disease extent was associated with homozygosity of the G241 allele (82.7% vs 64.7%, Pc = 0.0040). These data support linkage for CD at 19p13 and suggest that the amino acid polymorphisms in ICAM-1 may be associated with IBD.

The IBD6 Crohn's disease locus demonstrates complex interactions with CARD15 and IBD5 disease-associated variants

Genetic studies in inflammatory bowel disease have identified multiple susceptibility loci, whose relevance depends critically on verification in independent cohorts. Genetic variants associated with Crohn's disease have now been identified on chromosomes 5 (IBD5/5q31 risk haplotype) and 16 (IBD1 locus, CARD15/NOD2 mutations). Stratification of genome-wide linkage analyses by disease associated variants is now possible, offering both increased power for identification of other loci and improved understanding of genetic mechanisms. We performed a genome-wide scan of 137 Crohn's disease affected relative pairs from 112 families. Multipoint non-parametric linkage analyses were performed, with further stratification of affection status by common CARD15 mutations and the IBD5 haplotype. We verified linkage of Crohn's disease to regions on chromosome 3 (P=0.0009) and X (P=0.001) in our cohort. Linkage to chromosome 16 (IBD1) was observed in Crohn's disease pairs not possessing common CARD15 mutations (P=0.0007), approximately 25 cM q telomeric of CARD15. Evidence for linkage to chromosome 19 (IBD6) was observed in Crohn's disease pairs not possessing CARD15 mutations (P=0.0001), and in pairs possessing one or two copies of the IBD5 risk haplotype (P=0.0005), with significant evidence for genetic heterogeneity and epistasis, respectively. These analyses demonstrate the complex genetic basis to Crohn's disease, and show that the discovery of disease-causing variants may be used to aid identification of further susceptibility loci in complex disease.

Fine mapping of the IBD1 locus did not identify Crohn disease-associated NOD2 variants: implications for complex disease genetics

Crohn disease (CD) is a chronic relapsing inflammatory condition of the gastrointestinal tract. Recently, polymorphisms in NOD2 (CARD15), a gene mapping to the chromosome 16 IBD1 susceptibility locus, have been associated with susceptibility to CD. One group identified the gene by using classic positional cloning methods. Here, we report linkage and fine mapping analyses using 27 microsatellite markers encompassing the IBD1 susceptibility locus in 131 CD affected sibling pairs, and a simplex family cohort. No evidence for linkage was observed, and microsatellite markers close to NOD2 did not show association. However, significant association was confirmed in 294 CD trios for the NOD2 variants Arg702Trp and Leu1007fsinsC. Our fine mapping study of the IBD1 locus did not enable us to identify NOD2 as a CD gene, despite the presence of association with disease-causing alleles. This study illustrates the difficulties facing microsatellite linkage and linkage disequilibrium mapping methods for identifying disease genes in complex traits.

Use of commercially available radiation hybrid panels

Several panels are available for puchase, and this unit provides update information on the use of the three commercially available panels and on the interpretation of mapping results using the Internet. Radiation hybrid panels continue to serve as integral biological reagents in physical mapping projects and positional cloning.

Molecular markers reveal differentiation among isolates of Coccidioides immitis from California, Arizona and Texas

Coccidioides immitis causes coccidioidomycosis, a fungal disease of both immuno-compromised and otherwise healthy people; it is capable of causing large epidemics and the disease is often refractory to chemotherapy. To quantify the magnitude of population differentiation and estimate levels of gene flow in C. immitis, multilocus genotypes were scored for 20-25 clinical isolates from each of Bakersfield (California), Tucson (Arizona), and San Antonio (Texas). The molecular markers used were PCR products with polymorphic restriction endonuclease sites, found and characterized in a previous study of the Tucson population. The data show very highly significant differences in allele frequencies between all three populations, and suggest very low levels of migration between populations. One isolate in the San Antonio sample was an outlier, showing the California-specific allele at all four of the loci distinguishing the two populations, and subsequent inquiries indicated that the infection had indeed been acquired in California. Thus, genetic information can be used to infer the geographical origin of a fungal infection.