The right medicine, for the right patient at the right time. That’s the powerful promise of personalised or precision medicine, which often harnesses technologies such as genomic analysis to tailor treatments for individual patients.
The approach has been making strides in cancer therapy and more recently in areas such as neurology. But for it to benefit more patients, it needs research with wide skill sets, a better environment for gathering and sharing data and a keen eye for the economic and societal impact.
Personalised medicine has revolutionised how we treat some types of cancer, according to medical oncologist Prof Maeve Lowery, who describes how we have moved to more nuanced strategies to tackle cancerous cells in the body.
“Cancer cells have the ability to multiply quickly, and many chemotherapy treatments for cancer simply stop cells from doing that,” explains Lowery, who is professor of translational cancer medicine at Trinity College Dublin. “But we have lots of fast-growing cells in our bodies, and if the chemo drugs affect those cells too, then the patient can experience side effects like hair loss, problems with digestion and susceptibility to infections.”
Precision medicine takes a more targeted approach, homing in on nuances of the cancer cells, she explains: “One way we can do that is to better understand the molecular underpinnings of what is making this particular tumour grow and spread, often by analysing the DNA of the cancer, and then we develop a treatment to specifically block those processes.
“This approach can have more of an impact on the cancer cells and less risk of those side effects that can come with broader treatments, so we can really give the cancer cells a good dose of the treatment and the patient can hopefully tolerate that well.”
The last two decades or so have seen enormous strides in precision strategies entering the clinic, particularly for some forms of breast, lung, stomach and skin cancers, says Lowery who is also academic director at the Trinity St James’s Cancer Institute.
They can sometimes involve eye-wateringly expensive drugs, but the effects can be remarkable for individuals, adds Lowery who spoke recently at a Health Research Board conference on personalised medicine in Ireland. “Being able to target a mutation that is driving a patient’s cancer can really have astonishing clinical results.”
However, she points out the precision approach can help only with the cancers where their Achilles’ heels can be detected and targeted, and even at that, tumours may become resistant to treatment over time. “This is an area where we need more research,” she underlines.
Her own research in the Science Foundation Ireland-funded Precision Oncology Ireland Consortium is looking at unusual presentations of gastrointestinal cancers, to examine their molecular signatures for new potential targets for treatments.
This and any research in personalised medicine needs careful co-ordination and an environment where researchers can gather, access and share information about the cancers, she notes. It also needs the right set of skills in the research team to find the answers.
“We really need support for the people who can bring this about, the clinical scientists, geneticists, bioinformatics experts and many more,” she says. “We also need flexible designs in clinical trials, we need to work with patients and we need access to tests for patients so we can characterise tumours and share the findings with other researchers and clinicians, to make those findings even more powerful.”
Nuances in neurology
While cancer is one of the most obvious fields where personalised medicine is showing up for patients, neurology is seeing moves in that direction too, according to Prof Norman Delanty, a consultant neurologist at Beaumont Hospital and RCSI University of Medicine and Health Sciences. He specialises in diagnosing and treating the epilepsies.
“There are many genes in which mutations can lead to epilepsy,” he says. “And if we can find those mutations, in some cases we can design therapies to help the patient.”
Delanty has seen many such cases, including one where whole-exome sequencing – a sweep of the coding portions of a person’s DNA – revealed a mutation in a gene involved in managing sodium in the brain.
“Based on this, we were able to switch the patient to a different medication, and that had a hugely beneficial impact on their seizures,” he explains. “In another case, genomic analysis pointed to a patient having trouble with metabolising sugars, and a managed change in diet improved their seizures dramatically.”
Such successes hinge on being able to carry out appropriate testing, Delanty notes, who is an investigator at the Science Foundation Ireland FutureNeuro Research Centre. “If we can’t do that for patients, if we don’t have the precision diagnostics, then we can’t have the precision therapies,” he says.
He welcomes the publication late last year of the National Strategy for Accelerating Genetic and Genomic Medicine in Ireland by the HSE, but stresses that this is just the beginning of what needs to happen.
“We need the resources to be able to carry out precision testing where a patient might benefit, we need patient registers where we can gather and share the information about tests and mutations and we need bioinformaticians, people with the skills to drive this research,” Delanty adds.
“We also need an environment that makes it straightforward and time-efficient for clinicians and scientists to do the research, where important things like ethics approvals and consent and data transfer are streamlined so that everything works quickly and smoothly.”
Having electronic patient records across the board in Ireland would grease the wheels for precision-based approaches, according to biomedical scientist Prof Patricia Maguire.
She leads the AI-PREMie project, which is looking for new ways to diagnose and predict pre-eclampsia, a potentially life-threatening condition in pregnancy that can often lead to babies needing to be delivered early.
“At the moment we don’t have a way to predict early on in pregnancy which 8 per cent of women will develop pre-eclampsia later on, and then if pre-eclampsia is diagnosed we don’t know how it will go,” explains Maguire, who is a professor of biochemistry at University College Dublin.
“So we are analysing blood samples from women across Ireland who have suspected pre-eclampsia, monitoring changes in their blood and linking that to how the pregnancy progresses. Then we use machine learning to find patterns in the results that could underpin new predictive tests.”
Getting a better understanding of how pre-eclampsia is likely to unfold in the pregnancy could also help when deciding whether and when to deliver the baby. “The longer the pregnancy can go on safely for mother and baby in pre-eclampsia, the better the chance of a good outcome for both,” she says.
A key enabler for this more tailored approach patient care lies in electronic health records, Maguire says. “Some hospitals have them, some don’t, but we really need a single electronic health record for every patient that works everywhere and that the appropriate people can access.”
Researchers seeking to strengthen personalised medicine also need to think about the value of their approach, she adds. The AI-PREMie project now includes Prof Gerardine Doyle at UCD Smurfit School, who is analysing the economic and societal impact of a more tailored approach to managing pre-eclampsia.
“We are focused on the outcomes and impact on the patients – as we should be – but we also need to consider how improving outcomes can provide value across the board,” Maguire says. “Because at the end of the day, we need to resource these kinds of precision approaches.”