Biologic medications have transformed the treatment landscape for autoimmune and chronic inflammatory diseases. While initiation often comes from specialists like rheumatologists, dermatologists, and allergists, clinicians are increasingly likely to encounter patients who are taking or being considered for biologic therapy. Understanding how these medications work, what conditions they treat, and the safety implications is essential for providing comprehensive care.
Biologics are a class of targeted therapies derived from living cells—usually proteins—that are designed to interrupt specific components of the immune system. Unlike traditional small-molecule drugs that are chemically synthesized and often act broadly, biologics target specific immune pathways like tumor necrosis factor (TNF), interleukins (ILs), and immunoglobulins.
They are most commonly administered via subcutaneous injection or intravenous infusion and have become first-line or adjunct therapies in several chronic conditions.
Biologics are approved for a wide range of inflammatory and immune-mediated diseases, typically when conventional therapy fails. Common indications include:
▪️Moderate to severe asthma
Commonly Prescribed Biologics
|
Medication |
Target |
Indications |
Route |
|
Adalimumab (Humira) |
TNF-α |
RA, Crohn disease, psoriasis, uveitis |
Subcutaneous |
|
Etanercept (Enbrel) |
TNF-α |
RA, psoriasis, ankylosing spondylitis |
Subcutaneous |
|
Infliximab (Remicade) |
TNF-α |
Crohn disease, RA, ulcerative colitis |
IV infusion |
|
Ustekinumab (Stelara) |
IL-12/23 |
Psoriasis, Crohn disease, ulcerative colitis |
SC/IV |
|
Dupilumab (Dupixent) |
IL-4 receptor α |
Asthma, eczema, nasal polyps, eosinophilic esophagitis |
Subcutaneous |
|
Omalizumab (Xolair) |
IgE |
Allergic asthma, chronic urticaria |
Subcutaneous |
While generally well-tolerated, biologics come with specific risks due to their immunomodulatory effects. Common adverse effects include injection site reactions (pain, redness, swelling), headache, fatigue, and nausea/GI upset. There is a serious risk of infections, especially bacterial, fungal, or latent infections like TB, while on biologic therapies. Biologics that suppress immune function, like TNF-α inhibitors, are more likely to increase the risk of infection. Reactivation of TB and hepatitis B and C is also a risk with TNF-α inhibitors.
Clinical Tip: Teach patients on a biologic to notify you if they have any signs of infection, especially signs of TB, including fever, cough, and night sweats.
Hypersensitivity reactions or anaphylaxis have been reported with all biologic medications. There has been a rare association with lymphoma or other malignancies, including non-melanoma skin cancer. Hepatotoxicity is another recognized risk of biologic medications.
Even if you are not the one who has initiated the biologic therapy, as a clinician, you may play a critical role in screening for adverse effects, serious risks, and monitoring biologic therapy. Some biologics require baseline tests to screen for latent infections and underlying conditions prior to initiation. The screening requirements vary by biologic but can include:
▪️TB screening: QuantiFERON-TB Gold or TST prior to TNF inhibitors
▪️Baseline labs: Complete blood count (CBC), liver function tests (LFT), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), depending on the agent and condition.
Additionally, some biologics may require frequent lab monitoring during therapy, including CBC and LFTs. Patients should have regular office visits to monitor for infections, as well as their response to therapy. Patients on biologics also have specific vaccine guidance. Live vaccines, including MMR and varicella, are contraindicated during most biologic therapies.
💡 Clinical Tip: Administer all needed vaccines before starting biologic therapy when possible. It is advised to administer all live vaccines at least 4 weeks before initiating biologic therapy and to avoid live vaccine administration for up to 3 months after discontinuation.
Inactivated vaccines such as influenza, COVID-19, Tdap, and pneumococcal vaccines are considered safe during biologic therapy.
Biologics have revolutionized care for many patients with chronic inflammatory diseases, offering relief and disease control where older therapies have failed. As a clinician, your role is pivotal in ensuring that these powerful agents are used safely, effectively, and in collaboration with specialists. Staying current with biologic options, monitoring guidelines, and patient education can significantly improve outcomes and empower patients in their care journey.