What Are Biologics?

The term “biologic” refers to a wide group of therapies used to treat many different types of medical conditions, such as rheumatoid arthritis and cancer. You might also hear them called “biologic therapies,” “biological therapy,” or even “biopharmaceuticals.” Biologics are different from standard drugs, which can be created without using any living substances. In comparison, scientists require some living component to make a biologic.

Many biologics are cutting-edge therapies, and they are often expensive. They must be prepared and administered more carefully than many standard drug treatments. They also usually can’t be taken orally, so you’ll need to receive an injection or an infusion to receive your treatment.

Many biologics are considered more effective than their alternative, non-biologic drug options. Each year, the U.S. Food and Drug Administration (FDA) approves new biologic therapies for a variety of medical conditions.

What Do Biologics Do?

Biologics have different impacts on the body and different purposes, depending on their class, design, and their specific use. 

Autoimmune and Inflammatory Conditions

Many, but not all, biologics work by targeting a specific part of your immune system and causing it to respond in a certain way. 

For example, some biologics can be very helpful in treating autoimmune conditions, which cause your body's immune system to mistakenly attack healthy cells, causing symptoms such as inflammation, fatigue, and pain, among others. Biologics can also be helpful for some conditions that aren’t necessarily autoimmune but still cause excess inflammation. 

A biologic can target a very specific part of your immune system. For example, the TNF-blocker Humira (adalimumab) works by controlling the effects of tumor necrosis factor (TNF), a protein made by your immune system that can promote inflammation. This contrasts with non-biologic drug treatments, which tend to have broader effects on your immune system. 

The following are only some of the autoimmune and inflammatory conditions for which biologics are sometimes helpful:

• Rheumatoid arthritis
• Psoriasis and psoriatic arthritis
• Atopic dermatitis
• Asthma
• Inflammatory bowel disease
• Lupus
• Multiple sclerosis
• Ankylosing spondylitis
• Vasculitis

Cancer

A variety of biologics are also sometimes used to treat many different kinds of cancer, often paired with other kinds of treatments. 

For example, Keytruda (pembrolizumab) is a type of biologic treatment that can be used to treat many different kinds of cancer, including some kinds of lung cancer, melanoma, lymphoma, stomach cancer, and some breast cancers. It works by targeting a specific protein found in certain immune cells called T cells. This helps the T cells kill cancer cells more easily.

Your healthcare provider might not always mention the word “biologic” when talking about these treatments. Often when people are talking about biologics in the context of cancer treatment, they use the word “immunotherapy” instead.

Miscellaneous

These are only some general categories of conditions for which biologics are used. Some other applications include:

• Osteoporosis
• Macular degeneration and diabetic eye complications
• Certain infections, like rabies, anthrax, or COVID-19
• Alzheimer’s disease
• Rare genetic diseases, like blood clotting disorders such as hemophilia

However, not everyone with conditions such as these will need biologic therapy.

Types of Biologics

The term "biologics" often refers just to the types of products sometimes used to treat autoimmune diseases. However, there are several types of biologics. They are generally categorized based on how they work and the cells that they address.

Monoclonal Antibodies 

Monoclonal antibodies are basically modified antibodies. Antibodies are cells that help fight foreign invaders in your body (like bacteria and viruses). But unlike the antibodies your immune system naturally makes, technicians use parts of mice and human antibodies to make many antibodies that are targeted against a specific part of the body. These can be made in a variety of different ways. 

If a product has “ab” at the end of its name, it’s a good clue that you are probably dealing with a monoclonal antibody. Another closely related kind of biologic, fusion proteins, are basically modified versions of monoclonal antibodies.

Some examples of monoclonal antibodies used in autoimmune or inflammatory conditions include:

• B-cell-related monoclonal antibodies: Rituxan (rituximab)
• TNF blockers: Remicade (infliximab), Humira (adalimumab), Cimzia (certolizumab pegol), and Simponi (golimumab)
• IL-4 blockers: Dupixent (dupilumab)
• IL-5 blockers: Nucala (mepolizumab)
• Blockers of IL-6: Actemra (tocilizumab)
• Blockers of IL-17: Cosentyx (secukinumab), Taltz (ixekizumab), and Siliq (brodalumab)
• Blockers of IL-12 and/or IL-23: Stelara (ustekinumab), Skyrizi (risankizumab), Tremfya (guselkumab)

Monoclonal antibodies are also an important part of some cancer treatment regimens. Some examples include:

• Herceptin (trastuzumab)
• Avastin (bevacizumab)
• Kadcyla (trastuzumab emtansine)
• Keytruda (pembrolizumab)
• Opdivo (nivolumab)
• Blincyto (blinatumomab)

Prolia (denosumab) and Evenity (romosozumab) are two monoclonal antibodies used to treat osteoporosis. Lucentis (ranibizumab) and Zaltrap (aflibercept) are two examples used to treat eye problems such as macular degeneration. 

Other Biologics

Because they are made with living components, the following types of treatments are also all technically biologics. However, they aren't always referred to in this way. Examples include:

• Blood products such as red blood cells or platelets
• Tendons, ligaments, or other tissues used for transplantation
• Vaccines to prevent certain infections
• Vaccines to treat or prevent certain cancers
• Antitoxins, such as those used to treat a snake bite
• Proteins synthesized in a lab, like insulin
• T-cell therapies (CAR-T cell therapy), such as Breyanzi (used to treat to treat lymphoma)
• Stem cell therapies
• Gene therapies
  

How Are Biologics Taken?

Biologics can’t generally be taken as pills or liquids. Instead, you might take your biologic as an injection. Because biologics are delicate, they must be stored correctly (often in the refrigerator). Other biologics are given as infusions which you usually receive in a clinic. 

Most biologics don’t need to be taken every day. Instead, you receive the biologic on a medical schedule according to the specific product and your medical situation. For example, if you were taking Humira (adalimumab) for rheumatoid arthritis, you might give yourself an injection every other week. But some other biologics might be taken monthly or even less frequently. 

In certain situations, you take a biologic only for a limited time. For example, you might take a biologic to treat cancer only temporarily. You might take a biologic to treat osteoporosis until your bone strength has improved.

Other times, people take biologics chronically, for years or decades. This might apply to someone taking a biologic for an autoimmune disease like rheumatoid arthritis. 

Potential Side Effects

The potential side effects of a biologic vary widely based on the specific biologic and the clinical context. 

Common Reactions

Symptoms like headache, rash, or mild flu-like symptoms are some of the most common, especially in the day or so after you receive your treatment. You also might notice some mild redness, stinging, or bleeding in the area where you had an injection.

Infusion Reactions

Infusion reactions are another potential side effect of some biologic therapies. These might occur within minutes to an hour of receiving a biologic infusion. Such reactions might cause symptoms such as the following:

• Headache
• Dizziness and shortness of breath
• Itchiness
• Nausea and vomiting
• Rash
• Fever
• Heart palpitations

Usually, these reactions are mild. However, sometimes they may be more severe (such as difficulty breathing) and require immediate medical attention. 

Broad Impacts to Organ Systems

Many different organ systems can be affected by biologics, depending on the agent used and your specific medical risks. These are usually rare, but some potential examples include:

• Liver problems
• Lung problems, like interstitial lung disease
• Skin issues, like atopic dermatitis
• Anemia
• Neurological symptoms, like nerve pain
• Heart problems, like worsened heart failure
• Gastrointestinal problems, like a hole (perforation) in your intestines

Infection Risks

Many biologics work by suppressing parts of the immune system. While this can help reduce symptoms from your disease, it may also put you at greater risk of certain infections. There’s also a risk that an existing infection like hepatitis C might become more active if you start taking a biologic.

To minimize your risk of side effects, you may need certain tests before starting a biologic, like tests for specific infections or blood tests of your liver and kidneys.  

Cancer Risks

Some studies have shown that certain biologics might increase the risks of some cancers, like lymphoma. But the results of this have not been totally clear, and the risks, if they exist, seem small. More research is needed to determine if there is a connection between biologics and cancer risk.

Other Considerations

Biologics are complicated, and many people have questions about their terminology and their treatment options.

Biologics and DMARDs

Some people get confused about biologics and DMARDs (disease-modifying anti-rheumatic drugs). 

DMARDs are agents used to decrease your future symptoms from disease by addressing some of the key causes. This contrasts with treatments that immediately address your symptoms, like pain relievers. Traditionally these have been used for conditions like rheumatoid arthritis, but now they are sometimes used for conditions like inflammatory bowel disease (IBD).

Some DMARDs are standard pharmaceutical drugs, sometimes called “conventional DMARDs.” Other DMARDs are biologics. In the past, healthcare providers have often prescribed biologic DMARDs only after a person has tried conventional DMARDs that haven’t provided enough relief. But in some areas of medicine, healthcare providers are trying to move people to biologic DMARDs more quickly.

Biologics and Biosimilars

The relationship between biosimilars and biologics is also confusing. The term “biosimilar” applies to a subset of biologics. 

Because of the complex nature of these substances, it’s impossible for new companies to make completely identical products to an existing biologic approved by the FDA. However, companies can make biosimilar products that have the same design as an existing biologic. 

These new products can’t exactly be considered “generics,” because they aren’t manufactured as traditional pharmaceuticals. However, they can go through a shorter approval process through the FDA. If the FDA approves a biosimilar product, that means it should be just as safe and effective as the original biologic product. 

For example, multiple biosimilars are now available for the biologic product Humira (adalimumab). Depending on your insurance coverage, you might be required to get a biosimilar product instead, such as Amjevita (adalimumab-atto).

When to Call Your Healthcare Provider

If you notice mild, manageable side effects from your biologic, like rash or headache, you can discuss how to manage them at your next appointment. 

For more significant symptoms, like yellowed skin or whites of the eyes, severe fatigue, increasing breathlessness, or tingling in your extremities, call your healthcare provider’s office for input.

For serious and potentially life-threatening symptoms, like severe abdominal pain, sudden chest pain, or extreme difficulty breathing, seek immediate medical attention by calling 911.

A Quick Review

Biologics are a class of medical therapeutics made with living organisms. They are more complex than pharmaceutical drugs, and they can’t be manufactured as easily. Biologics are delicate and require careful storage, and they usually can’t be taken orally. They are usually expensive, but they may be more effective than older disease treatments. 

The FDA has approved many different kinds and classes of biologics. Often when people use the term “biologic,” they are referring to monoclonal antibodies, which can be used to treat a number of different autoimmune and inflammatory conditions, as well as cancer. 

If you are considering a biologic, your healthcare provider will need to screen you for conditions that might make biologics riskier. Although most people do very well on these therapies, they can cause serious side effects in some people, as well as some suppression of the immune system.