Landmark patient trial to use genetic testing to personalise treatments
Published: 17 June 2025
A major new study launching in Scotland aims to show how a simple genetic test could help doctors personalise treatments – boosting medication response and reducing harmful side effects.
A major new study launching in Scotland aims to show how a simple genetic test could help doctors personalise treatments – boosting medication response and reducing harmful side effects.
The PHOENIX Study, one of the largest trials of its kind in the world, will recruit up to 4,000 patients over the next two years in the NHS Greater Glasgow and Clyde area, in order to investigate how an individual’s genetic profile affects their response to 60 commonly prescribed medications. Researchers hope the trial will pave the way for more tailored prescribing across the NHS.
Led by Sandosh Padmanabhan, Pontecorvo Chair of Pharmacogenomics at the University of Glasgow, the PHOENIX Study will take place at the Queen Elizabeth University Hospital (QEUH) in Glasgow in partnership with the University of Glasgow’s Living Laboratory, the NHSGGC-hosted West of Scotland Innovation Hub, and industry partners MyDNA and Agena Bioscience.
Recruitment for the trial began this Spring and focuses on patients who are newly prescribed one or more of the 60 widely used medications in the NHS. With consent, participants will undergo a simple genetic test to analyse their DNA. The results – returned within days – will help doctors determine whether each patient is receiving the most suitable drug and dosage based on their genetic makeup.
Around 15% of patients are expected to carry genetic variants that may reduce the effectiveness of a medication or increase the risk of side effects. In some cases, the prescribed drug may be ineffective; in others, a different dosage may be needed. Without prior genetic testing, these issues can go unnoticed, often leading to a trial-and-error approach to treatment.
Pharmacogenomics (PGx) – the study of how genes influence individual responses to drugs – offers a way to personalise prescribing and improve outcomes. Yet this approach has not been routinely used in clinical practice in the UK. The PHOENIX Study seeks to provide the real-world evidence needed to change that.
Patients in the study will have a range of health conditions and be treated in different specialties across the hospital, including cardiology, stroke, surgery, general medicine, orthopaedics, geriatrics, gynaecology, ENT, rheumatology, respiratory, neurology, psychiatry and other specialities. The trial is open to adult in-patients of all ages in the QEUH. Patients enrolled on the PHOENIX trial will be randomly assigned to either receive the pharmacogenomic test immediately or at three months, which will allow the researchers to establish evidence of benefit.
The genetic test results will be sent to clinicians managing each patient’s care, allowing for treatment decisions to be adjusted. Patients will be followed up regularly to monitor the effects of any changes, helping ensure they continue to receive the highest standard of care.
Eric Balish is one of the first patients to be enrolled into the PHOENIX Study. He was asked to take part in the trial by consultants at the Queen Elizabeth University Hospital in Glasgow, after having a heart attack. Eric was immediately prescribed clopidogrel, one of the 60 drugs included in the study, but has since had his medication changed a number of times.
Now, just over a month after surgery, Eric is recovering. Like all patients on the trial, he doesn’t know which arm of the study he has been assigned to, but he feels positive about the information taking part might bring for himself and others.
He said: “I knew a bit about personalised medicine previously, and so when I was asked to take part in the PHOENIX Study I was happy to do it. 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. I am hopeful my information can be of use to the trial and in the future.”
Professor Sandosh Padmanabhan, who is also a consultant at the QEUH, said: “Physicians and pharmacists increasingly recognise that PGx-informed prescribing and dispensing improves both the efficacy and safety of drug treatment.
“The primary goal of this trial is to evaluate the clinical and health-economic impact of PGx-guided prescribing.
“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. This evaluation will compare the outcomes of participants who receive PGx-guided medication management to those receiving standard care.”
Dr Katriona Brooksbank, Research and Innovation Lead for NHSGGC and the West of Scotland Innovation Hub, said: “We are incredibly excited to be supporting this trial, which could have a major impact on the treatments patients are prescribed based on their own genetics.
“It will put precision medicine into action as researchers look to determine how a person’s own genetic make-up can affect the drugs they are given as treatments.
“This could allow clinicians to reduce adverse reactions and side effects, ensuring the best possible outcomes for patients.”
If successful, the PHOENIX Study could lead to wider implementation of genetic testing in prescribing across Scotland, making precision medicine a routine part of healthcare.
Allan Sheffield, Co-Founder of MyDNA, said: "For MyDNA, the PHOENIX Study embodies the future of healthcare. Our unique combination of pharmacogenomic clinical decision support and in-house Gene by Gene accredited testing empowers clinicians to move beyond guesswork. This trial will demonstrate the profound impact of precision medicine, paving the way for a future where this approach routinely drives better patient outcomes."
Enquiries: ali.howard@glasgow.ac.uk or elizabeth.mcmeekin@glasgow.ac.uk
First published: 17 June 2025