Side Effects of Biologic Therapies
Biologic therapies, or biotherapies, are medications that are derived from living organisms to treat diseases. They can be produced in a lab or derived from humans or animals to suppress or modify the immune system. They are unlike broad-spectrum immunosuppressants because they laser-focus on the target(s) that are responsible for inflammation. This means fewer systemic side effects, though they do still have them. In this blog, we will discuss the most common side effects of biologic medications used to treat lupus.
It is important to remember that medications used to treat lupus are not “one-size-fits-all”. Lupus is heterogeneous, meaning signs and symptoms vary widely from person to person, as do the immune triggers that drive the disease. This also means doctors carefully consider the best course of treatment for each individual and that each treatment plan is unique to the individual. Biologic medications are generally added as treatment options for patients who are not responding to standard treatments like hydroxychloroquine or prednisone alone.
The following are biologic medications used to treat lupus and lupus nephritis and their most common side effects. This list is not inclusive and does not review severe side effects, nor is it a substitute for your doctor’s advice. It also does not include any contraindications. Please speak with your doctor or refer to the manufacturer’s website for additional information.
- Belimumab (BENLYSTA®) – targets a B-lymphocyte stimulator (BlyS). Approved for use in SLE and LN. The most common side effects of BENLYSTA® include nausea, diarrhea, fever, stuffy/runny nose, sore throat, persistent cough, trouble sleeping, leg and arm pain, depression, headache (migraine), pain, redness, itching, or swelling at the site of the injection.
- Anifrolumab (SAPHNELO®) – blocks the receptor for type 1 interferons, which are a major cause of inflammation. Approved for use in SLE. The most common side effects of SAPHENELO® are upper respiratory infections, bronchitis, infusion reactions (when given intravenously), shingles (herpes zoster), and cough.
- Obinutuzimab (GAZYVA®) – an anti-CD20 therapy which depletes CD20 positive B lymphocytes. Approved for use in LN and is under review for SLE. Common side effects of GAZYVA® include upper respiratory tract infection, COVID-19, urinary tract infection, bronchitis, pneumonia, infusion-related reactions, and low white blood cell counts (neutropenia).
- Rituximab (RITUXAN®), which targets CD20 +B cells, is also used off-label for lupus, often for cases where other treatments aren’t working. Off-label means that a doctor wants to use an FDA-approved drug for unapproved use. RITUXAN® is FDA-approved for rheumatoid arthritis and some cancers, but not for lupus. However, some lupus patients respond well to RITUXAN®. Common side effects of RITUXAN® include infusion-related reactions, infections (which may include fever and chills), body aches, tiredness, and nausea.
Most side effects occur in less than 10% of individuals. In addition, some of the minor side effects, such as nausea, fatigue, headache, etc. can be treated symptomatically, or may even resolve during continued use of the biologic medication.
Before starting a new biologic medication, talk openly with your healthcare provider about what to expect – including rare but severe side effects. It would also be a good idea to discuss any vaccinations, for example pneumonia or shingles, prior to starting any biologic therapy. Having these honest conversations with your doctor ensures you stay informed and actively engaged in building the best treatment plan for your care.
This article was medically reviewed by Stanley Ballou, MD on August 4, 2026.