As Dr Tim Rendell reveals that Day Lewis will be beginning a pharmacogenomics pilot in 2023, we asked him what a national service in primary care and community pharmacy could look like.

What is pharmacogenomics?

We all have about 99.9% the same DNA, but it's that 0.1% that gives us different hair colour, different eye colour, and also the way that we actually metabolise drugs.

There is a real opportunity in the future to better use this new technology to personalise medicine. What pharmacogenomic testing will do is it will ensure that we're getting the right medicine for the right patient based on their genetic makeup.

What role could pharmacists play?

About 20% of patients with a new medicine have a potential drug gene interaction, and for 10% of patients there’s an opportunity to change the dose or the drug altogether.

In community pharmacy, the opportunity is when a new medicine is prescribed by the prescriber. The pharmacist will do the new medicine service with the patient and then follow it up with the genetic testing.

When could we see this in the UK?

I think that it's very possible that it can be piloted over the next 12 months. The technology is there, the tests are there, the service specifications are there.

On the back of the research that we've done over the last four years, at Day Lewis we are hoping to launch a service next year.

What will Day Lewis’ pilot look like?

Initially, it'll be a private service here. And I think that that's important because for commissioners to be able to actually see what the service looks like, and to do an evaluation on that service is going to really build competence going forward.

The patient will be given a PDF for all of their medicines, and that can be used for future prescribing. But it does take all health care practitioners to be able to move into that space. Prescribers particularly can be inundated with results from private tests at the moment, and that's one of the issues that needs to be ironed out.

We very much hope to publish the results of the trial. At the moment, we are still developing the exact service. We've got the evidence-based research to know as to how to do it, but we’re developing the service specification as to exactly what we're going to do.

What do pharmacists need to do to get ready for pharmacogenomics?

One of the main things is to understand what the service actually is.

I'm really keen to say that it's not just clinical geneticists that will need to understand and use this technology, but it should be available for all community pharmacists to eventually be able to offer the service.

So it is important to understand the underpinning science – but that’s exactly what it is, underpinning. Once the pharmacist has the underpinning science, they then need to understand how to offer the service, to look at case studies, to understand some of the pros and cons of the service, to understand how to have the interaction with the GP, how to explain the service to patients to better explain what it is, to explain what it's not and effectively the patient journey.

And with that training, it's very possible for both community pharmacists and pharmacy technicians to offer the service.

How can prescribers and dispensers work well together to deliver this service?

Our research involved talking to patients, GPs and pharmacists. It was really clear that for a successful launch, there should be an initial meeting with the community pharmacist and the prescriber. At their first meeting, they would discuss the service in general, and they would do a test – an actual physical test – on each other. Just to really have that experiential learning. And a couple of weeks later when the result comes back, they would discuss each other's tests report. That generates a lot of energy and a real understanding of what the service is.

Once they've done that they would then agree locally – because it's very different in each PCN – how they'd like to be communicated with – for instance, how many practitioners would be involved and whether it’s done by email or telephone.

It's very easy just to say ‘send the results to the GP’, but that means so many different things in so many different settings, and particularly when prescriber is asked to change the prescription there's got to be really high levels of confidence and relationship between the two health care professionals.

Will community pharmacies need access to patient notes to enable this service?

In an ideal world, again, there'll be complete interoperability between the pharmacist and the GP. I guess that eventually will come – it has to come – but that certainly I don't think will happen in 2023. It could be several years out.

A pragmatic solution will therefore need to be in place for the early pilots, probably where the pharmacists will download the report in a PDF format from the testing laboratory.

That PDF can then be shared with the patient and using NHS mail shared with the GP. It can be stored on the pharmacist’s PMR and the GP’s system too. It's certainly not ideal, but better, I believe, than waiting until that interoperability is in place.

Do you think that pharmacogenomics could help make the case for pharmacists delivering clinical services?

I think it builds on the armoury, because this is one more test in the prescribing armoury. Particularly with prescribing pharmacists coming on stream at pace, this is another really good tool that they can use for effective prescribing.

How can pharmacists explain the service to patients well? Is patient understanding about pharmacogenomics going to be a big hurdle to overcome?

In our research, patients had a really strong view about how to appropriately discuss this. DNA does have negative connotations for some patients – for some, it's about ancestry, for some it’s about predisposition to future disease states.

And pharmacogenomics is not about either of those, pharmacogenomics is just about testing for about 100-150 medicines, and then suggesting whether that is the right medicine for them based on their genetic profile.

It’s that reassurance of not just calling it a DNA test, but saying: how we can use testing to use new technology to identify if the medicine is the best fit for the patient according to their genetic makeup?

What could a national pharmacogenomics service look like to begin with?

As with any new technology, I think the endpoint would be where it could be for every patient on every new medicine, and they would be able to get the report for all of the drugs. You only need one test once in a lifetime – some of the evidence will change and it may affect the outcome, but the patient's DNA test doesn't change.

Getting to that endpoint is a very different matter to where we are today. I think it may have to start small, it may even have to start as a private service and then be commissioned by some of the ICSs and then if the evidence is there, it could go on to be a nationally commissioned service.

Equally, one way is to start with all the drugs that are available, however some of the research across the world started with just classes of drugs or even individual drugs.

Do you think there is appetite within the NHS and within ICSs for pharmacogenomic testing in community pharmacy to be commissioned?

Absolutely. The NHS genomic medicines service is one of the leading services globally. And with the formation of the Genomic Medicine Service Alliances and the new pharmacist leads developing new services as part of the NHS, the strategy effectively is for genomics to be part of the mainstream NHS by 2025.

There’s massive support from both Genomics England and the NHS to develop these services. But as always, trying to find pragmatic solutions to implement in a cost-effective way is always a challenge any new service.

Do you think that pharmacogenomic technology could be cost-effective in the long run?

There needs to be more research, and of course the cost of the test is always reducing. 10 years ago, a test effectively cost a million pounds to sequence one person’s whole genome. And then that came down to about 1,000 pounds five years ago, and today you’re in the hundreds. So in another five or ten years time – it’s only heading in one direction.

Adverse drug reactions are believed to account for 6.5% of all hospital admissions in England with an annual cost to the NHS of over £450m. If 10% of medicines prescribed out of a billion a year are potentially inappropriate for the patient, it doesn't take much to add up! It can only be a good thing.

Why are you excited about this service?

Once I had my test done, I could really see the benefits for patients and that's why part of the recommendation is the pharmacist and the GP do the tests on each other. Once you have it done yourself you think well, what about my family? What about my patients? You really want everyone to have that insight as to how it affects them.

In April, a landmark report from the British Pharmacological Society and Royal College of Physicians concluded that pharmacogenomic testing should be offered across the NHS.