Personalized medicine improves chances of recovery

Personalized or individualized medicine seeks to find the most suitable medical treatments for patients based on their personal characteristics. Rather than assuming that the same drug will work equally well for every patient, individual factors are taken into account when choosing a treatment. These factors primarily consist of biological traits such as genes and other biomarkers that are detected in the blood or tissue. For certain types of cancer and certain infectious diseases in particular, personalized treatments are already being used in many cases today.

Often, the same medication doesn’t work as effectively for some patients as for others. In some cases, the medication may be ineffective or may cause side effects. With a personalized approach, the most effective medication can be selected for the individual patient before treatment begins. This can also reduce the risk of side effects. 

One crucial advantage of personalized medicine is the possibility of making treatments more effective. For example, if a person’s biological characteristics are taken into account when choosing a therapy, this can significantly increase the effectiveness of their treatment. In addition to better treatment results, this approach may also reduce side effects by excluding unsuitable therapies from the outset. By avoiding unnecessary therapies, this also reduces costs in the healthcare system.

In personalized medicine, various tests are required before treatment begins. Blood or tissue samples are taken to identify whether certain biomarkers are present. These biomarkers include, for example, proteins on the surface of cells or genetic information (genes). Doctors can use the results of testing to determine whether a certain drug is suitable for treatment of a specific patient. 

In principle, personalized drugs work the same way as other drugs. What sets them apart, however, is that they are only effective in treating a certain group of people who have specific biological characteristics.

In the area of cancer treatment, for example, certain markers (biomarkers) are present in the cancer cells of some patients. These same biomarkers are not present in other patients with the same type of cancer. Certain drugs will be considered for treatment based on whether or not the patient has these biomarkers. Such drugs include, for example, monoclonal antibodies. These bind directly to the biomarkers and therefore to the cancer cells, slowing the growth of the cancer. In the area of cancer medicine, this approach is also known as targeted therapy. 

In addition to monoclonal antibodies, personalized medicine may also use small molecules. These are substances that are small enough to penetrate cancer cells, where they are able to interrupt signal chains. The personalized selection of the substance used ensures that the precise signal chain that promotes the growth of the relevant cancer cells is interrupted.

Personalized therapies are not available to treat every disease. Various personalized therapies are currently used to treat cancer and infectious diseases in particular. 

Examples include: 

• breast cancer
• chronic myeloid leukemia (CML)
• lung cancer
• melanoma skin cancer
• bowel cancer
• HIV
• hepatitis C 

Example: Targeted interruption of cancer cell growth in breast cancer

In breast cancer, cells grow uncontrollably in the tissue of the mammary glands. The cells can penetrate into surrounding tissue and destroy it. There are many different forms of breast cancer. In some people, for example, the number of HER2 proteins on the surface of the cancer cells is significantly increased. As a result, the tumor often grows relatively quickly. However, the HER2 protein also serves as a biomarker. If a person has a type of breast cancer with an increased number of these proteins, therapies to target HER2 can be used. The drugs bind to the HER2 proteins, blocking further growth signals for the tumor.

Example: Avoiding side effects through genetic testing in the treatment of HIV

HIV (human immunodeficiency virus) destroys specific cells in the immune system. If left untreated, a HIV infection therefore leads to an immune deficiency and secondary diseases (AIDS). Drugs to treat HIV can protect patients from this immune deficiency. One of these drugs is called abacavir. While it works well for many patients, it causes side effects that are sometimes life-threatening in approximately 5 percent of people. It is now understood that these severe side effects only occur in people with a certain gene. This gene can be detected by DNA analysis of a blood sample. People who don’t carry the gene can be treated with the HIV drug abacavir. Meanwhile, alternative HIV drugs are available for carriers of the gene.

To date, personalized medicine has primarily made significant progress in the treatment of cancer, whereas no personalized approaches are available for many other diseases. One reason for this is that a number of key biomarkers have already been identified for cancer. This, in turn, facilitates the use of personalized treatment approaches.

However, challenges still persist in cancer medicine, as cancer cells often contain many different mutations in their genetic material. Not all of these mutations are yet known or have been studied in detail. This means that, while drugs can be used to block individual cancer-inducing mechanisms, this is often not enough to completely stop the cancer from growing due to the many mutations within the cancer cells.

Another complicating factor for personalized approaches is the fact that the development of new therapies is both complex and expensive. Extensive clinical trials are needed before a drug can be placed on the market. In addition, individual countries have their own regulations governing the approval of new therapies. As a result, a drug approved in the USA may not be approved in the EU.

Despite these challenges, the area of personalized medicine is very promising. Thanks to continuous progress, personalized treatments may soon be possible for a wider range of illnesses.