Have you recently started treatment with belimumab (sold under the brand name Benlysta) for lupus? Are you wondering whether it’s working and when you’ll start to feel better?

Belimumab can be an effective treatment option for adults and children (age 5 and older) with systemic lupus erythematosus (SLE), cutaneous lupus erythematosus (CLE, lupus that affects the skin), and lupus nephritis — kidney disease caused by lupus.

More than 4,300 members of MyLupusTeam report taking it. Belimumab has been shown to help decrease lupus disease activity and the need for long-term use of medications like steroids. However, it might take months to see and feel its benefits.

Read on to learn how belimumab works to control lupus and why it may take longer than other lupus treatments to feel like it’s working.

How Belimumab Works

Belimumab is a biologic medication, or one made from natural sources. It’s the first targeted biological treatment approved by the U.S. Food and Drug Administration (FDA) for treating lupus .

Belimumab is a monoclonal antibody that works to block the activity of B-lymphocyte stimulator (BLyS), a protein that promotes the survival of B cells. B cells are white blood cells that usually produce antibodies to fight off invaders like viruses and bacteria in the body. However, in the case of lupus and other autoimmune diseases, B cells create high levels of autoantibodies, which attack a person’s own cells and tissues.

Belimumab is considered a B cell depletion therapy, because it works to eliminate B cells. While other lupus treatments work to reduce systemic inflammation throughout the body, belimumab targets B cells, or the source of inflammation, directly. Reducing B cell activity leads to lower levels of autoantibodies, and thus lower lupus disease activity and symptoms.

Belimumab has been shown to be effective in treating active autoantibody-positive SLE and active lupus nephritis by reducing the levels of autoantibodies. This lowers the risk of severe lupus flares and reduces the amount of steroids needed to control lupus. Researchers also have found that it can help improve CLE.

How Long Does It Take To See Belimumab’s Effects?

Belimumab will take some time before reaching its full effect. It may take anywhere from a few weeks to 12 weeks before you notice belimumab working, and four to eight months before you can feel its full effect in relieving symptoms like joint pain and fatigue. It might take even longer for some people.

It’s important to keep taking belimumab as instructed by your doctor, as long as you tolerate it well and don’t experience severe side effects. Even if you don’t notice an improvement within several months, continuing the medication will allow you and your doctor to see if it will eventually work and how effective it is.

Several members of MyLupusTeam shared their experiences with taking belimumab:

• “Benlysta worked really well for me. It takes a little time for it to get to strength, so a little patience goes a long way.”
• “Benlysta infusions really helped with my joint pain and fatigue for a couple years. It took about four months of treatment before I realized how well it was working.”
• “I noticed a difference on my fourth time, which was my first monthly treatment. I really feel much better since I’ve been taking Benlysta.”

Why Does Belimumab Take a While To Work?

Belimumab works to reduce the number of B cells in lupus through a gradual process. In a research study on the safety and effectiveness of belimumab, scientists found the number of a set of B cells targeted by belimumab was reduced after four to eight weeks of treatment, and that it took even longer to see an improvement in lupus symptoms.

While belimumab takes some time to work, research has found that it’s effective at reducing the number of B cells in the long term. One study found that people with lupus who took belimumab for over six years had between 40 percent and 99 percent reduction in the amount of B cells.

Researchers have also found that taking belimumab in the earlier stages of lupus was more effective at treating lupus symptoms.

Side Effects of Belimumab

Belimumab treatment is given as an infusion into your veins, or an intravenous (IV) infusion. To receive treatments, you need to go to a medical clinic where a health care professional will give you an IV infusion. For adults with lupus, there’s also the option to administer it to yourself as a subcutaneous injection (injection under the skin) at home using a prefilled syringe autoinjector. This method isn’t currently an option for children.

Choosing to take belimumab through IV infusion or subcutaneous injection doesn’t seem to affect how long it takes to start working. You won’t experience faster results if you choose one method over the other.

Infusion Reactions

Infusions of belimumab can cause hypersensitivity or infusion reactions. This reaction may happen during the infusion or days to weeks afterward. Signs of an infusion reaction include:

• Rash
• Nausea
• Fatigue
• Muscle pain
• Headache
• Swelling in the face

If you experience any of these symptoms during or after your infusion, tell your infusion nurse or doctor right away. A belimumab infusion should only be given by health care providers prepared to manage anaphylaxis (severe allergic reaction) and infusion reactions. Your doctor can prescribe medications before your belimumab infusion to help lower the risk of hypersensitivity or infusion reactions.

Other Side Effects

Serious side effects of belimumab include an increased risk of serious infections, certain types of cancer, and depression or thoughts of suicide. Be sure to let your doctor know immediately if you notice any signs of infection or changes in your mental health.

General side effects of belimumab include:

• Nausea
• Diarrhea
• Fever
• Inflamed airways
• Trouble sleeping
• Depression
• Migraine
• Injection site reaction (from a subcutaneous injection)

These side effects should go away as your body becomes adjusted to belimumab. If they persist or become worse, contact your doctor for medical advice right away.

Treatment Options While You’re Waiting for Belimumab To Take Effect

Belimumab is usually given in combination with other standard therapies for lupus. These may include:

• Antimalarial medications, including hydroxychloroquine and chloroquine
• Immunosuppressive medications, including azathioprine (Imuran), methotrexate, and mycophenolic acid (Myfortic)
• Corticosteroids, including prednisone

When used in combination with other lupus medications, belimumab may reduce the dose of prednisone needed to control inflammation from lupus. If your symptoms persist and do not improve after you have started belimumab treatment, talk to your rheumatologist. They may adjust the doses of other lupus medications given with belimumab to manage your symptoms until belimumab’s effects kick in.

Talk to Your Doctor About What To Expect While on Belimumab

While belimumab can be an effective treatment option for many people with SLE, CLE, or lupus nephritis, it can take months before it starts improving your lupus symptoms. Talk to your doctor to learn the benefits and risks of belimumab and what to expect once you start the treatment.

Talk With Others Who Understand

MyLupusTeam is the social network for people with lupus and their loved ones. On MyLupusTeam, more than 223,000 members come together to ask questions, give advice, and share their stories with others who understand life with lupus.

Did you recently start belimumab treatment? If you have taken belimumab for lupus, how long was it until you noticed an effect? Share your experience in the comments below, or start a conversation by posting on MyLupusTeam.