Cost-Utility Analysis of Pharmacogenetic Testing Based on CYP2C19 or CYP2D6 in Major Depressive Disorder: Assessing the Drivers of Different Cost-Effectiveness Levels from an Italian Societal Perspective

Association of pharmacodynamic genes with treatment outcomes in major depressive disorder: results from a Sardinian cohort

We examined the association of selected candidate pharmacodynamic (PD) genes in MDD with treatment outcomes, defined according to remission thresholds for Hamilton Depression Rating Scale (HDRS) with 6- and 17- items. To this end, we recruited 158 individuals living with MDD followed in an academic community mental health center. We reconstructed their clinical history and tested the association of a selected panel of pharmacodynamic genes with clinical remission. Our multivariate models were corrected for illness duration, substance use, lifetime stressful events, and sex. We found partially concordant associations for candidate biomarkers and clinical remission defined with HDRS-6 and HDRS-17. In the logistic regression model, two polymorphisms were statistically significantly associated with HDRS-17 remission: namely rs10975641 and rs11628713. Our results suggest that polymorphisms in PD genes might influence clinical response in MDD. Interestingly, we showed some degree of concordance of the association depending on the definition of the response.

A naturalistic retrospective evaluation of the utility of pharmacogenetic testing based on CYP2D6 e CYP2C19 profiling in antidepressants treatment in a cohort of patients with major depressive disorder

Response to antidepressants (ADs) is highly variable and partly genetically driven, but the utility of pharmacogenetic testing in guiding ADs treatment is still controversial. We conducted a retrospective, naturalistic study to explore the utility of CYP2C6 and CYP2C19 genotyping in ADs treatment in a sample of 156 patients diagnosed with major depressive disorder from south Sardinia (Italy). Clinical data, including history of medication regimens, adverse reactions, and response to ADs were collected over the last five years preceding recruitment. Patients received pharmacogenetic testing at recruitment and were classified depending on whether their history of treatment regimen followed the recommendations of the Clinical Pharmacogenetics Implementation Consortium (CPIC)). Non-responders to ADs had a larger number of therapeutic regimens and of medication changes due to lack of response compared to responders. Patients with at least one incongruent regimen had a larger number of total therapeutic changes and fewer congruent regimens. Metabolizing phenotypes of CYP2D6 were not associated with response to ADs or changes in regimen of any kind. However, the group of ultra-rapid metabolizers for CYP2C19 showed significantly smaller improvement in symptoms while the poor-metabolizers showed a larger number of medication changes for side effects compared to normal, intermediate and rapid metabolizers. Our findings suggest that the implementation of pharmacogenetic testing based on CYP2C19 could be clinically useful in guiding AD treatment, but further studies are warranted to investigate the clinical implications of implementing PGx testing in depression.

Cost-effectiveness of pharmacogenetic screening in the management of major depressive disorder in the Spanish Healthcare System

BACKGROUND

Major depressive disorder (MDD) represents a sizable economic burden in Spain. Pharmacogenetic (PGx) screening to guide the choice of antidepressant medication (ADM) in MDD patients yields higher response and remission rates, which could reduce both healthcare and indirect costs.

METHODS

We built a cost-effectiveness probabilistic Markov model with microsimulation using Tree Age Pro 2022, simulating a patient cohort from the SNHS starting ADM for MDD, and comparing PGx screening before starting ADM versus no screening (No PGx). We carried out a probabilistic sensitivity analysis using the Monte Carlo simulation with microsimulation, set for 1000 iterations and 1000 microsimulation trials, both from societal and healthcare provider perspectives, for a time horizon of 3 years.

RESULTS

From a societal perspective, the model estimated a mean cost of 3172.85€ and effectiveness of 2.64 quality-adjusted life years (QALYs) for the No PGx strategy, and a mean cost of 1687.02€ and effectiveness of 2.84 QALYs for the PGx strategy. The mean ICER was -7820.56 €/QALY. From a healthcare provider perspective (no indirect costs considered), the mean cost was 662.62€ for the No PGx strategy, and 446.60€ for the PGx strategy. The mean ICER was -1130.16 €/QALY.

LIMITATIONS

The heterogeneity of input data from the literature, the need for assumptions of homogeneous distribution of variables and events across population and time, and the inherent limitations of cost-effectiveness analysis should be considered. The model omits combined therapies (ADMs with mood stabilizers, antipsychotics, cognitive behavioral therapy…).

CONCLUSIONS

PGx screening in MDD prior to ADM start is a dominant strategy in the SNHS.

Cost-effectiveness analysis of genotype-guided optimization of major depression treatment in Qatar

Background

Pharmacogenetic testing improves the efficacy and safety of antidepressant pharmacotherapy for moderate-severe major depressive disorder by identifying genetic variations that influence medication metabolism, and adjusting treatment regimens accordingly. This study aims to assess the cost-effectiveness of implementing a pharmacogenetic testing approach to guide the prescription of antidepressants.

Methods

From the public hospital perspective, we developed a two-stage decision tree diagram of a short-term 6-week follow up, and a lifetime Markov model with 3-month cycles. The analysis compared the current standard of care with the alternative strategy of Pharmacogenetic-guided (multi-gene panel) testing in adult patients with moderate-severe major depressive disorder. Clinical outcomes and utilities were obtained from published studies, while healthcare costs were locally available. The short-term incremental cost-effectiveness ratio was against treatment response without side effects and without relapse, and against treatment response with/without side effects and without relapse. The long-term incremental cost-effectiveness ratio was against the quality-adjusted life year gained and years of life saved.

Results

Adopting the pharmacogenetic-guided therapy for adult patients with moderate-severe major depressive disorder in Qatar resulted in cost savings of Qatari Riyal 2,289 (95% confidence interval, -22,654-26,340) for the health system. In the short term, the pharmacogenetic-guided testing was associated with higher response rates without side effects and without relapse (mean difference 0.10, 95% confidence interval 0.09-0.15) and higher response rates with or without side effects and without relapse (mean difference 0.05, 95% confidence interval 0.04-0.06). For long term, the pharmacogenetic-guided testing resulted in 0.13 years of life saved and 0.06 quality-adjusted life year gained, per person, along with cost savings of Qatari Riyal 46,215 (95% confidence interval-15,744-101,758). The sensitivity analyses confirmed the robustness of the model results.

Conclusion

Implementing pharmacogenetic testing to guide antidepressant use was found to improve population health outcomes, while also significantly reducing health system costs.

Clinical implementation of preemptive pharmacogenomics in psychiatry

BACKGROUND

Pharmacogenomics (PGx) holds promise to revolutionize modern healthcare. Although there are several prospective clinical studies in oncology and cardiology, demonstrating a beneficial effect of PGx-guided treatment in reducing adverse drug reactions, there are very few such studies in psychiatry, none of which spans across all main psychiatric indications, namely schizophrenia, major depressive disorder and bipolar disorder. In this study we aim to investigate the clinical effectiveness of PGx-guided treatment (occurrence of adverse drug reactions, hospitalisations and re-admissions, polypharmacy) and perform a cost analysis of the intervention.

METHODS

We report our findings from a multicenter, large-scale, prospective study of pre-emptive genome-guided treatment named as PREemptive Pharmacogenomic testing for preventing Adverse drug REactions (PREPARE) in a large cohort of psychiatric patients (n = 1076) suffering from schizophrenia, major depressive disorder and bipolar disorder.

FINDINGS

We show that patients with an actionable phenotype belonging to the PGx-guided arm (n = 25) present with 34.1% less adverse drug reactions compared to patients belonging to the control arm (n = 36), 41.2% less hospitalisations (n = 110 in the PGx-guided arm versus n = 187 in the control arm) and 40.5% less re-admissions (n = 19 in the PGx-guided arm versus n = 32 in the control arm), less duration of initial hospitalisations (n = 3305 total days of hospitalisation in the PGx-guided arm from 110 patients, versus n = 6517 in the control arm from 187 patients) and duration of hospitalisation upon readmission (n = 579 total days of hospitalisation upon readmission in the PGx-guided arm, derived from 19 patients, versus n = 928 in the control arm, from 32 patients respectively). It was also shown that in the vast majority of the cases, there was less drug dose administrated per drug in the PGx-guided arm compared to the control arm and less polypharmacy (n = 124 patients prescribed with at least 4 psychiatric drugs in the PGx-guided arm versus n = 143 in the control arm) and smaller average number of co-administered psychiatric drugs (2.19 in the PGx-guided arm versus 2.48 in the control arm. Furthermore, less deaths were reported in the PGx-guided arm (n = 1) compared with the control arm (n = 9). Most importantly, we observed a 48.5% reduction of treatment costs in the PGx-guided arm with a reciprocal slight increase of the quality of life of patients suffering from major depressive disorder (0.935 versus 0.925 QALYs in the PGx-guided and control arm, respectively).

INTERPRETATION

While only a small proportion (∼25%) of the entire study sample had an actionable genotype, PGx-guided treatment can have a beneficial effect in psychiatric patients with a reciprocal reduction of treatment costs. Although some of these findings did not remain significant when all patients were considered, our data indicate that genome-guided psychiatric treatment may be successfully integrated in mainstream healthcare.

FUNDING

European Union Horizon 2020.

Assessing the utility of measurement methods applied in economic evaluations of pharmacogenomics applications

An increasing number of economic evaluations are published annually investigating the economic effectiveness of pharmacogenomic (PGx) testing. This work was designed to provide a comprehensive summary of the available utility methods used in cost-effectiveness/cost-utility analysis studies of PGx interventions. A comprehensive review was conducted to identify economic analysis studies using a utility valuation method for PGx testing. A total of 82 studies met the inclusion criteria. A majority of studies were from the USA and used the EuroQol-5D questionnaire, as the utility valuation method. Cardiovascular disorders was the most studied therapeutic area while discrete-choice studies mainly focused on patients' willingness to undergo PGx testing. Future research in applying other methodologies in PGx economic evaluation studies would improve the current research environment and provide better results.

The role of pharmacogenomics in precision psychiatry

The field of psychiatry is facing an important paradigm shift in the provision of clinical care and mental health service organization toward personalization and integration of multimodal data science. This approach, termed precision psychiatry, aims at identifying subgroups of patients more prone to the development of a certain phenotype, such as symptoms or severe mental disorders (risk detection), and/or to guide treatment selection. Pharmacogenomics and computational psychiatry are two fundamental tools of precision psychiatry, which have seen increasing levels of integration in clinical settings. Here we present a brief overview of these two applications of precision psychiatry in clinical settings.

Pharmacokinetic Markers of Clinical Outcomes in Severe Mental Illness: A Systematic Review

The term severe mental illness (SMI) encompasses those psychiatric disorders exerting the highest clinical burden and socio-economic impact on the affected individuals and their communities. Pharmacogenomic (PGx) approaches hold great promise in personalizing treatment selection and clinical outcomes, possibly reducing the burden of SMI. Here, we sought to review the literature in the field, focusing on PGx testing and particularly on pharmacokinetic markers. We performed a systematic review on PUBMED/Medline, Web of Science, and Scopus. The last search was performed on the 17 September 2022, and further augmented with a comprehensive pearl-growing strategy. In total, 1979 records were screened, and after duplicate removal, 587 unique records were screened by at least 2 independent reviewers. Ultimately, forty-two articles were included in the qualitative analysis, eleven randomized controlled trials and thirty-one nonrandomized studies. The observed lack of standardization in PGx tests, population selection, and tested outcomes limit the overall interpretation of the available evidence. A growing body of evidence suggests that PGx testing might be cost-effective in specific settings and may modestly improve clinical outcomes. More efforts need to be directed toward improving PGx standardization, knowledge for all stakeholders, and clinical practice guidelines for screening recommendations.

Validation of Pharmacogenomic Interaction Probability (PIP) Scores in Predicting Drug-Gene, Drug-Drug-Gene, and Drug-Gene-Gene Interaction Risks in a Large Patient Population

Utilizing pharmacogenomic (PGx) testing and integrating evidence-based guidance in drug therapy enables an improved treatment response and decreases the occurrence of adverse drug events. We conducted a retrospective analysis to validate the YouScript^® PGx interaction probability (PIP) algorithm, which predicts patients for whom PGx testing would identify one or more evidence-based, actionable drug-gene, drug-drug-gene, or drug-gene-gene interactions (EADGIs). PIP scores generated for 36,511 patients were assessed according to the results of PGx multigene panel testing. PIP scores versus the proportion of patients in whom at least one EADGI was found were 22.4% vs. 22.4% (p = 1.000), 23.5% vs. 23.4% (p = 0.6895), 30.9% vs. 29.4% (p = 0.0667), and 27.3% vs. 26.4% (p = 0.3583) for patients tested with a minimum of 3-, 5-, 14-, and 25-gene panels, respectively. These data suggest a striking concordance between the PIP scores and the EAGDIs found by gene panel testing. The ability to identify patients most likely to benefit from PGx testing has the potential to reduce health care costs, enable patient access to personalized medicine, and ultimately improve drug efficacy and safety.