Drug therapies do not always work as expected. In some patients, the efficacy of drugs remains non-existent, others experience adverse effects of various severities – life-threatening at worst. One of the factors affecting drug therapy is genetic variability. Understanding the role of genes has also sped up the development of genetic testing that supports successful drug therapy.

2.10.2024

Inspired by this thought, Niemi started working as a post-doc researcher in a prestigious pharmacogenetic research institution in Germany. There, further studies carried out in co-operation with German partners confirmed Niemi’s assumption concerning the role of genes.

Around the same time, an international genome project led by American researchers managed to determine the basic structure of the human genome. This resulted in high expectations from the field and provided pharmacogenetic researchers with numerous opportunities. His own observations and the spirit of the times sealed pharmacogenetics as the primary interest for Niemi.

“I returned from Germany in 2004 and set up a research group at the University of Helsinki. After the quiet phase that followed the initial hype, the field is currently experiencing strong growth. We have been gathering quite a lot of scientific evidence on the benefits of pharmacogenetic testing”, says Niemi, currently employed as a Professor of Pharmacogenetics.

Genetic testing is rapidly becoming more common

Niemi, who is considered to be among the pioneers in the field both domestically and internationally, believes that genetic testing will become more common in the coming years as test methods develop and their cost-benefit ratio improves.

“We also need more research data on the effects of genes on different pharmaceutical agents. At the moment, over a hundred drugs are known to be significantly affected by genes”, says Niemi.

According to Niemi, genetic testing provides valuable information that can be used to improve drug therapy outcomes, prevent adverse effects and save money.

“For the moment, tests are not utilised in the treatment of every patient but it is likely, at some point, that we all will have our pharmacogenetic profile determined. This will facilitate and speed up the detection and initiation of a suitable drug therapy, which will bring many benefits.”

“Genetic testing makes it possible to plan individual medication, in other words, to select drugs and dosages that best suit the patient.”

Towards individual drug therapy

In Niemi’s opinion, genetics has an indisputable impact on the efficacy and safety of drug therapy. As an example, he mentions the effect of genes on cholesterol-lowering agents, statins, which are often prescribed to patients with high cholesterol levels to prevent cardiovascular diseases.

“In some patients, the efficacy of statins remains low and, in others, they cause adverse effects – usually muscle pain. Many discontinue their medication due to fairly mild pain, since the drug does not alleviate any current symptoms but, instead, is used minimise future risks.”

However, it is not wise to stop the medication as this will increase the risk of developing serious diseases and cause many unnecessary deaths. In other words, a failed drug therapy becomes expensive in many ways.

Niemi has been studying statins for a long time. Now is known that the reason behind the muscle pain that often leads to discontinuation of medication is often a genetic variation that prevents the drug from working as planned.

“Instead of avoiding drug therapy, patients suffering from adverse effects should discuss their symptoms with their doctor. It may be possible to find a more suitable medication through genetic testing.”

According to Niemi, who is one of the most referenced scientists in the field of pharmacogenetics, genetic testing provides considerable benefits also to many patients suffering from depression. Genetic testing makes it possible to plan individual medication, in other words, to select drugs and dosages that best suit the patient.

“The evidence behind the benefits of genetic testing is so strong that tests have been added to the Current Care Guidelines for depression. When genetic information is utilised in the selection of an antidepressant, the likelihood that a patient becomes free of symptoms is up to 40 per cent higher than without genetic testing.”

Towards routine utilisation of genetic information

With increasing data received from genetic testing, attention should also be paid to the availability of the data.

“The data must be integrated in electronic health records so that they are readily available for clinicians. It is not enough that genetic test results are listed along with other laboratory test results – we need an automated system that transfers the genetic data to be included as a routine part of drug therapy”, Niemi points out.

For example, when treating chronic patients who require several different drugs, the benefits of genetic testing would be cumulated rapidly. Niemi believes that routine utilisation of gene information will be common everyday practice within 5–10 years in this patient group – and, gradually, in others as well.

When a drug therapy succeeds as expected, it benefits both the individual and society. The sooner the right medication is found, the better the treatment response and the less adverse effects that put a strain on the patient and health care system. There are also financial impacts.

“In the future, gene databases integrated in patient information systems will be a key tool for physicians. They will make physicians’ work easier and help them to find drugs that are effective and cause less adverse effects to their patients”, says Niemi.

Learn more about Pgxbase – it serves as a resource for tailoring drug therapies to the unique genetic profile of a patient. 

Text: Leena Hulsi
Photo: Linda Tammisto, Helsinki University