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Impact of Large-Scale Pharmacogenomic Testing On Adverse Events

Pharmacogenomics (PGx) continues to be an invaluable tool, critical to optimizing patient care and driving the field of precision medicine. By learning how an individual’s genes impact their health, physicians can make better-informed decisions on care. Several studies have highlighted the benefits of knowing gene variants — thus helping to determine who is and is not an ideal candidate — when prescribing medications1.

Understanding broad-scale implementation of PGx testing

Researchers have also begun learning about how PGx can impact health outcomes, particularly regarding adverse drug reactions from prescription medications. The recent PREPARE (Primary Prevention Parameters Evaluation) study found that testing for specific gene variants before prescribing medication significantly reduces adverse drug reactions2. It has been well documented in literature the benefit of PGx testing. However, the clinical utility of broad-scale implementation has been unclear. This is the first prospective study that investigated the benefits of a preemptive PGx panel across a range of diverse healthcare settings. Researchers from across Europe conducted this study in seven countries (Greece, Austria, Slovenia, the UK, Spain, Italy, and the Netherlands) by implementing a 12-gene panel looking for 50 germline variants.

The Dutch Pharmacogenetics Working Group (DPWG) and the Clinical Pharmacogenetics Implementation Consortium (CPIC) have created testing guides containing over 100 gene-drug pairs. The 12-gene panel used in the PREPARE study was selected based on criteria regarding drug response, protein functionality, and population frequency3. Developing panels that cover widely representative genes seen in multiple populations is imperative for capturing as many variants as possible to improve outcomes.

PGx testing significantly reduces clinically relevant adverse drug reactions

Overall, the study showed that pharmacogenetic testing significantly reduced the number of clinically relevant adverse drug reactions by 30 percent. Of the 725 people in the study group who had an actionable variant and received guided drug treatment, 152 (21 percent) experienced an adverse event. On the other hand, 231 out of 833 patients (28 percent) with an actionable variant who did not receive guided drug treatment experienced an adverse event.

The authors noted that few, often US-based, studies have investigated single drug-gene pairs in certain specialized healthcare settings. PREPARE was the first large-scale study conducted using a panel-based PGx testing system covering a broad range of diseases and therapeutic areas. The study also demonstrated the feasibility of using a large gene panel across several European countries and their diverse healthcare systems. Identifying the best medications to prescribe to patients minimizes the number of adverse events and reduces healthcare costs. On top of the clinical benefits, previous studies have highlighted that pharmacogenomic testing can save thousands of dollars in direct medical charges4.

Innovation and disruption in current models for PGx testing

By developing relevant drug-gene panels and integrating them into the healthcare system, precision medicine can become a reality. With Helix’s Sequence Once, Query Often™ model, healthcare providers can continue screening patients for new pharmacogenetic variants as needed. Through our population genomics programs and with just a single round of sequencing, Helix provides point-of-care genomic insights that allow healthcare providers to tailor prescriptions to each patient as a unique individual.

The results are given within a patient interaction and are immediately useful in treatment plan development and mitigating adverse drug reactions. From then on, the results are always available — as researchers learn more about new gene loci implications in drug metabolism, healthcare providers will be able to access data to update a patient’s treatment plan readily.

Implementing large-scale gene testing within a country’s healthcare system would reduce adverse events experienced with drug therapy. Helix has a proven track record of implementing large-scale genetic testing across diverse patient populations and health systems. Reach out to learn more about how our end-to-end population genomics platform helps healthcare providers make the most of their patients’ data to drive real-world success.

1. Chang K, Weitzel K, Schmidt S. Pharmacogenetics: Using genetic information to guide drug therapy. Am Fam Physician. 2015;92(7):588-595.
2. Swen JJ, van der Wouden C, Manson LEN, et al. A 12-gene pharmacogenetic panel to prevent adverse drug reactions: An open-label, multicentre, controlled, cluster-randomised crossover implementation study. Lancet. 2023;401:347-356.
3. van der Wouden C, van Rhenen MH, Jama WOM, et al. Development of the PGx-Passport: A panel of actionable germline genetic variants for pre-emptive pharmacogenetic testing. Clin Pharmacol Ther. 2019;106(4):866-873.
4. Jarvis JP, Peter AP, Keogh M, et al. Real-world impact of a pharmacogenomics-enriched comprehensive medication management program. J Pers Med. 2022;12(3):421. doi:10.3390/jpm12030421