Landmark PHOENIX study to generate real-world insights to personalize prescribing with genetic testing

The PHOENIX Study, one of the world’s largest pharmacogenomics trials, is using Gene by Gene’s accredited genetic testing to personalize prescribing for up to 4000 patients in NHS Greater Glasgow and Clyde (NHSGGC). The study aims to generate real-world evidence (RWE) on the impact of genetic testing in reducing adverse drug reactions and improving treatment effectiveness across 60 widely used medications.

The trial will recruit up to 4000 adult in-patients at the Queen Elizabeth University Hospital (QEUH) who are newly prescribed one or more of 60 commonly used medicines. Led by Professor Sandosh Padmanabhan, Pontecorvo Chair of Pharmacogenomics at the University of Glasgow and consultant at QEUH, the study will examine whether pharmacogenomic (PGx) testing can improve outcomes by identifying genetic variants that affect drug response.

“The primary goal of this trial is to evaluate the clinical and health-economic impact of PGx-guided prescribing,” he explained. “Specifically, we want to determine if a PGx-guided approach to prescribing can significantly reduce the incidence and severity of drug related side effects and/or treatment failures.”

Participants will be randomly assigned to receive a PGx test either immediately or after three months. The test, provided by Gene by Gene’s accredited laboratory, analyses each participant’s DNA to identify how they are likely to respond to medication. Results are delivered to the treating clinician within days, allowing for potential adjustments to dosage or drug selection.

The trial spans a wide range of clinical specialties, including cardiology, stroke, orthopedics, psychiatry, respiratory medicine, and more, reflective of a real-world environment where patients often take several medications and have multiple comorbidities. Approximately 15% of individuals carry genetic variants that may reduce the effectiveness of a medication or increase the risk of side effects, highlighting the need for evidence to guide safer and more effective prescribing.

“Physicians and pharmacists increasingly recognize that PGx-informed prescribing and dispensing improves both the efficacy and safety of drug treatment,” added Professor Padmanabhan.

One of the first patients to join the study, Eric Balish, was enrolled following a heart attack and subsequent treatment with clopidogrel, one of the study’s 60 drugs.

“If you're asked to participate and support long-term research like this, then it's no great hardship to give something back and just do the right thing,” said Eric. “I am hopeful my information can be of use to the trial and in the future.”

The PHOENIX Study is supported by the University of Glasgow’s Living Laboratory, the NHSGGC-hosted West of Scotland Innovation Hub, and industry partners myDNA and Agena Bioscience. Dr Katriona Brooksbank, Research and Innovation Lead for NHS Greater Glasgow and Clyde, said the study could be a turning point in how treatment decisions are made:

“It will put precision medicine into action... This could allow clinicians to reduce adverse reactions and side effects, ensuring the best possible outcomes for patients.”

Gene by Gene, a provider of accredited genetic testing services, is supporting the study by delivering PGx testing and clinical decision support. Allan Sheffield, Director of Gene by Gene and myDNA, said:

“This trial will demonstrate the profound impact of precision medicine, paving the way for a future where this approach routinely drives better patient outcomes.”

If successful, the PHOENIX Study will provide RWE to support the broader adoption of PGx testing across NHS Scotland, making personalized prescribing a routine part of clinical care.