Biologic drugs, also called biologics, are among the most advanced and effective treatments available for many complex diseases that were once difficult, or even impossible, to manage.
These medicines are developed from living cells rather than a standard chemical process. Unlike many traditional medications, which may act more broadly throughout the body, biologics are designed to target specific cells, proteins, or immune pathways involved in disease.
Today, numerous biologic drugs are being used to treat and manage a wide range of conditions such as autoimmune disorders, cancers, inflammatory diseases, diabetes, and rare genetic conditions. This article covers the basics of biologics, including what they are, how they work, and lists some of the top biologic drugs and the conditions they treat.
Basics of Biologic Drugs
Biologic drugs are made using advanced biotechnology techniques. Unlike traditional drugs, which are manufactured chemically, scientists use recombinant DNA technology and other genetic engineering techniques to program living cells, such as bacteria, yeast, or mammalian cells, to produce biologic medicines. The finished product is then extracted, purified, and tested to ensure its quality, safety, and effectiveness before use.
Some major examples of biologic drugs include monoclonal antibodies, proteins, hormones, vaccines, and growth factors.
Also, biologics are often larger and more complex molecules than synthetic drugs; they are administered into the bloodstream through injections or IV infusions. Because biologics are large protein molecules, they would be broken down by the digestive system if taken by mouth. As a result, most biologics are administered by subcutaneous injection or intravenous (IV) infusion.
How Biologic Drugs Work
Biologic drugs are designed to work in a specific way or interact with a specific molecule or pathway involved in disease progression. For instance, some biologic drugs block proteins that trigger inflammation in autoimmune diseases, while others help the immune system identify and kill cancer cells.
Biologics are often prescribed when conventional treatments are ineffective, cannot be tolerated, or when highly targeted therapy offers better disease control.
Commonly Prescribed Biologic Drugs
Currently, several types of biologics are available and indicated for the treatment of specific conditions. Here are some of the most commonly prescribed biologic drugs and the conditions they treat.
1. Humira (Adalimumab)
Humira (adalimumab) is one of the most commonly prescribed biologic drugs for patients with the following inflammatory and autoimmune diseases:
- Rheumatoid arthritis
- Psoriatic arthritis
- Crohn’s disease
- Ulcerative colitis
- Plaque psoriasis
- Ankylosing spondylitis
- Juvenile idiopathic arthritis
- Hidradenitis suppurativa
- Non-infectious uveitis
Humira is a monoclonal antibody and belongs to the tumor necrosis factor (TNF) inhibitor drug class. The monoclonal antibody blocks TNF activity (a protein that causes inflammation in autoimmune diseases) and helps reduce signs and symptoms of these diseases.
This drug is given as a subcutaneous injection (under the skin).
2. Keytruda (Pembrolizumab)
Keytruda (Pembrolizumab) is a targeted cancer immunotherapy and is prescribed to treat several types of cancers, including:
- Non-small cell lung cancer (NSCLC)
- Small cell lung cancer (SCLC)
- Melanoma
- Head and neck cancer
- Kidney cancer
- Bladder cancer and urinary tract cancer
- Breast cancer
- Cervical cancer
- Classical Hodgkin lymphoma
- Stomach cancer and certain colorectal and blood cancers
- Ovarian, fallopian tube, and primary peritoneal cancers
This biologic medicine belongs to the PD-1 inhibitor class. Keytruda helps the immune system recognize and attack cancer cells by blocking the PD-1 pathway that tumors use to avoid immune detection. Keytruda is administered as an intravenous (IV) infusion. Depending on the approved treatment regimen, it is typically given every 3 or 6 weeks.
3. Dupixent (Dupilumab)
Dupixent (Dupilumab) is an injectable biologic drug and a monoclonal antibody used to treat type 2 (or allergic) inflammation in people with:
- Asthma
- Atopic dermatitis (eczema)
- Nasal polyps
- Chronic obstructive pulmonary disease (COPD)
- Eosinophilic esophagitis.
Dupixent reduces inflammation by blocking two specific immune proteins, IL-4 and IL-13, which play a key role in type 2 inflammation. This drug is given as a subcutaneous injection under the skin using a pre-filled pen or pre-filled syringe.
4. Herceptin (Trastuzumab)
Herceptin (Trastuzumab) is a targeted biologic drug and belongs to the anti-HER2 drug class. This drug is designed to treat cancers that overexpress the HER2 protein. It is commonly prescribed to patients with:
- HER2-positive breast cancer
- HER2-positive gastric cancer
Trastuzumab, the active component of Herceptin, is a monoclonal antibody that attaches to HER2 receptors on cancer cells and blocks growth signals needed for cancer cells to grow. This drug is given as an IV infusion once every 1 to 3 weeks.
5. Enbrel (Etanercept)
Enbrel (Etanercept) is a prescription biologic medicine used to treat inflammatory and autoimmune diseases affecting joints and skin such as:
- Rheumatoid arthritis
- Plaque psoriasis
- Psoriatic arthritis
- Polyarticular juvenile idiopathic arthritis
Enbrel is an anti-TNF agent or TNF inhibitor that blocks the inflammation-causing TNF proteins in the body. It helps reduce symptoms related to autoimmune diseases, such as joint pain, swelling, and stiffness. It also helps reduce skin redness and scaling in patients with plaque psoriasis.
Enbrel is given as a shot under the skin once a week.
6. Avastin (Bevacizumab)
Avastin (Bevacizumab) is a monoclonal antibody designed to treat several types of cancer. It is prescribed to people with:
- Metastatic colorectal cancer
- Non-small cell lung cancer (NSCLC), glioblastoma
- Renal cell cancer
- Cervical, ovarian and fallopian tube cancer
Bevacizumab specifically targets and blocks vascular endothelial growth factor (VEGF), a protein that stimulates blood vessel formation in tumors. By blocking VEGF, Avastin helps slow tumor growth by preventing the formation of new blood vessels that supply tumors with oxygen and nutrients.
It is administered through an IV infusion into a vein, once every 2 or 3 weeks.
7. Stelara (Ustekinumab)
Stelara (Ustekinumab) is an injectable biologic drug and an interleukin inhibitor that specifically blocks the immune system’s proteins (IL-12 & IL-23) that contribute to inflammation. By blocking interleukins, it helps to reduce inflammation and relieve symptoms in people with Crohn’s disease, plaque psoriasis, psoriatic arthritis, and ulcerative colitis.
Stelara is administered as an injection under the skin every 8 weeks.
8. Rituxan (Rituximab)
Rituxan (Rituximab) is a prescription biologic that treats certain cancers such as non-Hodgkin’s lymphoma (NHL) and chronic lymphocytic leukemia (CLL) and non-cancer conditions including rheumatoid arthritis, polyangiitis, and pemphigus vulgaris.
Rituximab specifically targets and destroys the B-cells involved in the disease process. It is given as an intravenous infusion into a vein.
Rituxan was among the first monoclonal antibodies to demonstrate how targeted biologic therapies could successfully treat multiple disease types.
9. Neulasta (Pegfilgrastim)
Neulasta (Pegfilgrastim) is a biologic drug derived from the bacteria Escherichia coli. It stimulates neutrophil growth, a type of white blood cell that helps fight infection. Neulasta is administered as a subcutaneous injection (injected under the skin) to patients who have:
- Neutropenia (low neutrophil counts) associated with cancer chemotherapy
- Acute Radiation Syndrome (ARS)
This drug typically helps to prevent serious infection in cancer patients as well as increase survival in adults and children with ARS.
10. Xolair (Omalizumab)
Xolair (Omalizumab) is an anti-IgE monoclonal antibody and is available in injectable drug form. Xolair is used to treat allergic reactions and immune-mediated conditions in people. It is typically prescribed to patients with:
- Moderate-to-severe allergic asthma
- Chronic hives
- Food allergies
- Nasal polyps
Omalizumab binds to the IgE antibodies in the body and blocks the immune system’s allergic response, leading to decreased allergic responses and improved symptom control in patients. Xolair is injected under the skin every 2 to 4 weeks.
11. Lantus (Insulin Glargine)
Unlike monoclonal antibodies, insulin is a recombinant protein produced using biotechnology rather than being derived directly from human or animal sources.
Lantus (Insulin glargine) is a long-acting biologic insulin used to improve and manage blood glucose levels in patients with type 1 and 2 diabetes mellitus. It is usually administered once a day.
Lantus is produced by recombinant DNA technology using a non-pathogenic laboratory strain of Escherichia coli (K12) as the production organism.
Biologics vs. Biosimilars
Many biologic drugs now have biosimilars, which are highly similar versions of FDA-approved biologics. Unlike generic drugs, biosimilars are not exact chemical copies because biologics are produced in living cells. However, they have no clinically meaningful differences in safety, purity, or effectiveness compared with their reference biologic. Biosimilars can improve access to treatment by increasing competition and lowering healthcare costs.
Table 1: Concise Summary of Top Biologic Drugs
| Biologic Drug | Drug Class/ Target | Common Uses | How It Works | Administration |
| Humira (Adalimumab) | TNF inhibitor | Rheumatoid arthritis, Crohn’s disease, ulcerative colitis, psoriasis, ankylosing spondylitis | Blocks TNF protein to reduce inflammation | Subcutaneous injection |
| Keytruda (Pembrolizumab) | PD-1 inhibitor | Various cancers, including lung, melanoma, breast, kidney, and cervical cancers | Helps the immune system recognize and destroy cancer cells | IV infusion (typically every 3 or 6 weeks, depending on the indication). |
| Dupixent (Dupilumab) | IL-4 and IL-13 inhibitor | Asthma, eczema, COPD, nasal polyps, eosinophilic esophagitis | Reduces type 2 inflammation by blocking IL-4 and IL-13 pathways | Subcutaneous injection |
| Herceptin (Trastuzumab) | HER2-targeted monoclonal antibody | HER2-positive breast and gastric cancers | Blocks HER2 receptors and inhibits cancer cell growth | IV infusion (every 1–3 weeks) |
| Enbrel (Etanercept) | TNF inhibitor | Rheumatoid arthritis, plaque psoriasis, psoriatic arthritis, juvenile idiopathic arthritis | Reduces inflammation caused by TNF proteins | Subcutaneous injection (weekly) |
| Avastin (Bevacizumab) | VEGF inhibitor | Colorectal, lung, kidney, ovarian, cervical cancers, and glioblastoma | Prevents tumor blood vessel formation | IV infusion (every 2–3 weeks) |
| Stelara (Ustekinumab) | IL-12 and IL-23 inhibitor | Crohn’s disease, ulcerative colitis, plaque psoriasis, psoriatic arthritis | Blocks inflammatory interleukin proteins | Subcutaneous injection (every 8 weeks) |
| Rituxan (Rituximab) | Anti-CD20 monoclonal antibody | Non-Hodgkin’s lymphoma, chronic lymphocytic leukemia, rheumatoid arthritis, pemphigus vulgaris | Targets and destroys B-cells involved in disease | IV infusion |
| Neulasta (Pegfilgrastim) | Granulocyte colony-stimulating factor (G-CSF) | Chemotherapy-induced neutropenia and acute radiation syndrome | Stimulates neutrophil production to fight infection | Subcutaneous injection |
| Xolair (Omalizumab) | Anti-IgE monoclonal antibody | Allergic asthma, chronic hives, food allergies, nasal polyps | Blocks IgE-mediated allergic responses | Subcutaneous injection (every 2–4 weeks) |
| Lantus (Insulin Glargine) | Long-acting biologic insulin | Type 1 and Type 2 diabetes mellitus | Helps regulate blood glucose levels throughout the day | Subcutaneous injection (once daily) |
Bottom Line
Biologic drugs have transformed the treatment of many autoimmune diseases, cancers, and other serious medical conditions by targeting specific disease pathways. Although these medications can be highly effective, they may also cause serious side effects and require ongoing monitoring by a healthcare provider.
Before starting biologic therapy, talk with your healthcare provider to determine whether a biologic is appropriate for your condition. They can help select the most suitable treatment based on your diagnosis, disease severity, previous therapies, and overall health.
References
- Revers, L., & Furczon, E. (2010). An Introduction to Biologics and Biosimilars. Part I: Biologics: What are They and Where Do They Come from? Canadian Pharmacists Journal / Revue des Pharmaciens du Canada. https://doi.org/10.3821/1913-701X-143.3.134.
- US Food and Drug Administration (FDA). Humira (adalimumab) label.
- US Food and Drug Administration (FDA). Keytruda (Pembrolizumab) label.
- US Food and Drug Administration (FDA). Dupixent (Dupilumab) label.
- US Food and Drug Administration (FDA). Herceptin (Trastuzumab) label.
- US Food and Drug Administration (FDA). Enbrel (Etanercept) label.
- US Food and Drug Administration (FDA). Avastin (Bevacizumab) label.
- US Food and Drug Administration (FDA). Stelara (Ustekinumab) label.
- US Food and Drug Administration (FDA). Rituxan (Rituximab) label.
- US Food and Drug Administration (FDA). Neulasta (Pegfilgrastim) label.
- US Food and Drug Administration (FDA). Xolair (Omalizumab) label.
- US Food and Drug Administration (FDA). Lantus (Insulin glargine) label.