Medicine gets personal

Why personalised medicine is coming, and how it’s going to help us beat disease.

13th November 2017
Medicine gets personal © Tang Yau Hoong

Modern medicine, for all its wonders, has a rather large blind spot. Though scientific breakthroughs and new miracle treatments are announced on a seemingly daily basis, doctors know that even the most effective drugs in their arsenal won’t work for large sections of the population.

For example, the drugs commonly prescribed to treat disorders like depression, asthma and diabetes are ineffective for around 30-40 per cent of people they are prescribed to. With hard to treat diseases like arthritis, Alzheimer’s and cancer, the proportion of the population who see no benefit from a particular treatment rises to 50-75 per cent.

The problem stems from how treatments are developed. Traditionally, a drug is approved for use if it works for a good number of people with similar symptoms in a drug trial – and questions are not asked about those in the study who did not respond to the treatment. When the drug is then released and prescribed to the population en masse, unsurprisingly there are plenty of people – like those in the trial – who discover that the latest ‘miracle cure’ isn’t all that miraculous for them.

This ‘one size fits all’ system of drug discovery – though it helped uncover the most important medicines of the 20th Century – is now increasingly seen as ineffective, outdated and dangerous. It means medicines are developed to work on ‘the average person’, when in fact all of us – even our diseases and our responses to drugs – are unique. Not only are many drugs ineffective for large subsections of the population, but they can also cause severe adverse reactions in others.

Thankfully, a completely new approach to medicine is gaining ground. As we learn more about how people differ genetically, medical professionals are tailoring healthcare advice and medical treatment to individuals, rather than populations.

The personal touch

Personalised medicine (sometimes known as ‘precision medicine’) uses a patient’s genetic data, and other data about their health at the molecular level, to work out the best treatment for that individual person and others with a similar genetic profile.

We tend to think of our genes as determining things such as our height, eye-colour, or whether we have a genetic disorder. But the combination of genes we are born with affects our development and health in many subtle ways over the course of our lives. The likelihood of us getting certain diseases as we age, the way we metabolise food, and our reaction to certain drugs are all influenced by the genes we have.

Given what we now know about genes, taking this approach may seem somewhat obvious. But it has only been made possible in the last decade, thanks to the incredible progress that has been made in DNA sequencing technology.

When the human genome was first decoded in 2003, it took over a decade of international collaborative efforts and cost $3bn. Just 15 years later, sequencing a person’s genome takes hours rather than years, and can be done for under $1,000. This means genetic information is…

BBC Focus 315 extract

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