How personal is personalised medicine?

Personalised medicine holds the promise of revolutionising medical care. Who already benefits from it today? To be able to assess the potential of personalised medicine, we need a better understanding of what this term actually means.

Text: Stefan Schweiger; photo: Sanitas

What is personalised medicine?

Every person is different. Although two people may be diagnosed with the same illness on paper, the course of the disease may be quite different. One person may respond wonderfully to a drug, while another suffers almost unbearable side effects. Why is this? There is no doubt that focusing on the average patient in large clinical studies has driven medical progress. However, when one-size-fits-all treatments are applied to individual patients, they often do not have the desired effect, and can sometimes even cause unnecessary suffering.

Personalised medicine does not follow the “trial and error” principle; it aims to use medical data as a basis to predict as accurately as possible how the treatment might work for each individual. To do so, it analyses in detail the patient’s state of health, age and gender, right down to their genetic profile. After all, the structure of two people’s DNA differs by around six million base pairs. Not to mention the environmental influences that affect them individually over the course of a lifetime.

… and what is it not?

At first glance, medical care that focuses on the individual sounds empathetic and personal. In fact, personalised medicine comes across initially as rather clinical, because it relies on huge volumes of data to achieve a targeted treatment and an accurate diagnosis. However, medical care has always been at least a little personalised. For example, a 75-year old pensioner who has broken a bone in her forearm has always received different treatment to a 25-year old competitive athlete.

However, it is not the goal of personalised medicine to develop completely different treatments for every individual. Instead, the idea is to differentiate between subgroups of patients to such an extent that there is a very high probability that individual patients will benefit from a therapy without any side effects.

This approach is also known as “precision medicine” or “individualised medicine”. In contrast, “personalised health” is applied earlier. Instead of coming into play to treat an illness that has already developed, this approach introduces promising individual measures to help prevent it.

Did you know?

  • No fewer than 42% of the medicines approved in 2018 in the USA were personalised therapies (source: FDA).
  • The human genome has only been fully decoded since May 2021.
  • The genetic make-up of human beings is 99.9% identical. But that 0.1% difference is crucial.

More data, better medical care? Biomarkers as a driver of innovation

Similar to fingerprints, biomarkers are absolutely unique in every person: from the data recorded by the smartwatch on your wrist, your blood pressure, blood sugar levels and other laboratory values all the way through to sophisticated genetic analyses. In total, vast amounts of biomarkers, i.e. body data, can be collected on every individual person.

These digital ones and zeros than have to be put to good use, for example in predicting the probability that a person will develop a certain illness or how they would benefit from a specific treatment. We would never be able to handle this huge volume of data without high-performance computers.

Smart algorithms and artificial intelligence help identify patterns which previously would probably have gone unnoticed. Health data helps – as long as it isn’t collected purely for the sake of collecting data and it is protected against misuse.

Do we really want to know all this? The right not to know

You go for a routine check-up and, thanks to state-of-the-art screening, discover out of the blue that you have a genetic defect that might cause a rare but serious hereditary illness. But it might not. The results of genetic tests are not always black and white.

And it is this grey area that is characterized by uncertainty and can be hugely psychologically stressful. What would you do if an examination reveals that you have the same mutation of the “BRCA1” gene as the actress Angelina Jolie? A mutation that significantly increases your risk of developing breast cancer. Should you have both breasts removed as a precaution like Jolie? A person must not be left to make this decision on their own,

which is why medical professionals agree that genetic screening should always be done under medical supervision. But genetic tests that you can buy online don’t always provide this service. Every genome always has constellations that may cause concern. However, despite all the medical progress, you always have the right not to know, if that is what you want.

Who is already benefiting from personalised medicine today? Using cancer treatment as an example

Swapping gut instinct for data-based decisions makes life much easier for doctors. Personalised medicine has already improved oncology treatment. Cancer cells develop as a result of changes in cells known as mutations. However, not all cancers are the same.

This means that tumour tissue in two patients with the same disease may not necessarily contain the same mutations. For example, patients with breast cancer whose tumour cells contain an excess of the growth factor “HER2” benefit from a therapy that targets precisely this factor. If this is not the case, a patient doesn’t have to undergo this treatment at all. A suitable alternative needs to be found.

And with advanced bowel cancer, for example, certain antibodies can only be applied successfully if the “KRAS” gene has not already mutated. Similar approaches to precision medicine are already being used today in the treatment of HIV, Alzheimer’s and Parkinson’s or after organ transplantation.

Cost driver or secret weapon?

It is no secret that personalised therapies are expensive. However, researchers hope that they will pay off in the end if they make it possible to avoid unsuccessful and unnecessary treatments from the outset. It all depends on whether they prove to be cost-effective.

It is practically impossible at the moment to predict whether the investments made in personalised medicine today will even ease the pressure on the healthcare system in the future. However, the price development of genetic testing, for example, is encouraging. Not long ago, these tests were practically unaffordable, but they are now sometimes available online for less than CHF 100. So, personalised medicine may prove cost-effective, but perhaps not in every area of medicine.