Biologics

What are biologics?

Biologics are large-molecule substances that are produced in living organisms, usually using biotechnological processes. These drugs contain proteins, antibodies or other biological components that target specific molecular structures in the body. The most important classes of biologics include monoclonal antibodies, cytokines and fusion proteins.

Compared to chemical drugs, which are small molecules and can affect a variety of target structures in the body, biologics are often more targeted. They bind specifically to certain molecules or cells that are involved in the disease. In this way, they specifically interrupt pathological processes. This precision makes them particularly effective and at the same time reduces potential systemic side effects.

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How do biologics work?

The mechanism of action varies depending on the type of biologic. In general, they work by specifically binding to certain proteins or receptors in the body. This allows them to inhibit signalling pathways, activate the immune system or replace missing proteins.

• Inhibition of signaling pathways
  ‍Many biologics target pro-inflammatory molecules or receptors that are responsible for the progression of a disease. For example, some agents block specific cytokines that play a key role in inflammatory processes. By inhibiting these cytokines, the inflammatory response in the body can be reduced.
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• Activating the immune system
  ‍Some biologics stimulate the immune system to recognise and attack abnormal cells, such as cancer cells. Monoclonal antibodies, for example, can bind to cancer cells and activate the immune system to destroy these cells.
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• Substitution of missing proteins
  ‍In some genetic or metabolic diseases, the body may lack certain proteins or enzymes. Biologics can serve as a substitute. A well-known example of this is insulin, which is administered in diabetes mellitus to regulate blood sugar levels.
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Despite their good efficacy, biologics can cause side effects. The most common side effects include the risk of infection and allergic reactions. In rare cases, long-term use can lead to the development of autoimmune reactions. Studies also indicate that the risk of certain types of cancer may be increased.

Biological or biotechnological active ingredients are therefore used for different purposes. The following section takes a closer look at the mode of action of these biotechnologically produced active ingredients in common areas of application.

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Biologics for autoimmune diseases

In autoimmune diseases, the immune system mistakenly targets the body's own tissue. This is the case, for example, with inflammatory rheumatic diseases such as rheumatoid arthritis. Psoriasis, Crohn's disease and multiple sclerosis are also autoimmune diseases for which biologics can be used.

Mechanism of action in autoimmune diseases

In autoimmune diseases, biologics often interfere with the activity of cytokines that are responsible for the inflammatory reactions.

Active substances such as infliximab or adalimumab are TNF-α inhibitors. These inhibit the so-called tumour necrosis factor-alpha, a cytokine. This cytokine plays a central role in immunological inflammation and tissue destruction. By blocking this cytokine, the excessive immune response is reduced, which leads to symptom relief.

Possible side effects

The most common side effects include an increased risk of infections, as the immune response is weakened overall. Allergic reactions to the biologic may also occur. In rare cases, an autoimmune reaction can be triggered, in which the immune system acts against the administered biologic.

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Biologics in Oncology

In cancer treatment, biologics are used to combat tumour cells. Trastuzumab (Herceptin) or rituximab are examples of active substances that specifically bind to tumour cells and inhibit their growth.

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Mechanism of action in autoimmune diseases

In oncology, biologics are used that bind to specific receptors on the surface of cancer cells. In this way, they block signals that promote tumour growth. Other biologics mark cancer cells for the immune system so that they can be recognised as a target and destroyed.

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Possible side effects

In addition to general side effects such as weakness, nausea and flu-like symptoms, biologics in cancer therapy can also have specific side effects. These include reactions to the infusion, heart problems or an increased risk of secondary infections.

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Biologics for inflammatory bowel disease

Chronic inflammatory bowel diseases such as Crohn's disease and ulcerative colitis are characterised by chronic inflammation of the digestive tract. Biologics such as infliximab and adalimumab are available as treatment options.

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Mechanism of action in inflammatory bowel disease

Biologics block inflammatory mediators, such as TNF-α, which play a central role in the inflammatory response in the gut. By inhibiting these cytokines, the inflammatory response is interrupted and the symptoms of the disease can be alleviated.

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Possible side effects

As with other autoimmune diseases, there is an increased risk of infections as the functions of the immune system are inhibited. Side effects such as headaches, skin rashes or reactions at the injection site may also occur.