Saturday, Oct. 21
14:30 – 15:30 (N/A)
Meeting Room: Finback (3rd floor – B Tower)
Shahzad Ghanbarian*, PhD; Gavin Wong, PhD; Mary Bunka, BA; Louisa Edwards, PhD; Sonya Cressman, PhD MBA; Tania Conte, MSc; Morgan Price, MD PhD; Linda Riches, MSc; Ginny Landry, BSc; Kimberlyn McGrail, PhD; Jehannine Austin, PhD; Stirling Bryan, PhD

CanMEDS Roles:

1. Collaborator
2. Professional

At the end of this session, participants will be able to: 1) Learn about pharmacogenomic testing to improve antidepressant prescribing for major depressive disorder; 2) Summarize the best available evidence of pharmacogenomic-guided prescribing for major depression from existing randomized controlled trials; and 3) Share our evaluation of the effectiveness and cost effectiveness of pharmacogenomic testing for major depression as a routine component of depression care in BC.

Pharmacogenomics (PGx) testing, one of the most promising recent genomic advances, can guide prescribing in search of enhanced efficacy and fewer side effects. People with major depressive disorder (MDD) often receive pharmacological treatment, but finding an effective medication can be a lengthy trial-and-error process. Response to antidepressants partly reflects variation in genes that influence medication metabolism. PGx testing potentially represents a significant therapeutic advance. We sought to establish the cost-effectiveness of PGx for MDD patients.
Methods: We developed a microsimulation Markov model of MDD care pathways in BC to evaluate the effectiveness and cost effectiveness of PGx testing from the public payer’s perspective over 20 years. The model includes unique patient characteristics (e.g., metabolizer phenotypes) and uses estimates derived from systematic reviews, administrative data analyses, and expert judgements. We estimated incremental costs, life-years (LYs), and quality-adjusted life-years (QALYs) for a representative MDD patient cohort. We conducted a partial probabilistic analysis and several deterministic sensitivity analyses.
Results: If PGx testing is implemented in BC for adult patients with moderate to severe MDD, it is predicted to save the health system Can$848 million and bring health gains of 11,160 LYs and 63,696 QALYs over 20 years. These savings are mainly driven by slowing or avoiding the transition to refractory (treatment-resistant) depression. PGx-guided care is associated with 47% fewer refractory patients over 20 years. All sensitivity analyses supported the robustness of these findings. Probabilistic analysis revealed that the PGx-guided treatment dominated the current standard of care for most (96%) simulations.

References:

1. Bunka M, Wong G, Kim D, et al. Evaluating treatment outcomes in pharmacogenomic-guided care for major depression: a rapid review and meta-analysis. Psychiatry Res 2023;321:115102.
2. Bunka M, Ghanbarian S, Riches L, et al. Collaborating with patient partners to model clinical care pathways in major depressive disorder: the benefits of mixing evidence and lived experience. Pharmacoeconomics 2022;40(10):971–977.