Benlysta

What is Benlysta?

Benlysta is the trade name for an FDA-approved prescription drug called belimumab. It consists of a human monoclonal antibody (a laboratory-made protein) that inhibits B-cell activating factor (BAFF), or B-lymphocyte stimulator (BLyS), a naturally occurring protein in the body that is causing an abnormal immune response.

Benlysta is administered directly into a vein (or intravenous infusion). It is the first inhibitor manufactured to target the BAFF (or BLys) protein and to reduce the abnormal B cells believed to be causing autoimmune disorders such as systemic lupus erythematosus (SLE, or lupus).

Studies show that patients who receive Benlysta, together with standard therapies, experience less disease activity (fewer symptoms) than those who receive a placebo and standard treatments. Results suggest that it reduces the likelihood of severe flares, thereby reducing the need for high steroid doses.

This human monoclonal antibody was approved for the treatment of SLE by the FDA in 2011, making it the first of its kind specifically designed to treat lupus. In contrast, other drugs (steroids, antimalarial, immunosupressive, and organ-rejection drugs) are currently used as off-label treatments for lupus, which means that they were never FDA-approved specifically for lupus and may have serious side effects.

How does Benlysta work?

The body has B-lymphocyte cells that normally produce proteins (antibodies) to fight harmful viruses, bacteria, and other allergens (antigens). These immune cells are often triggered to attack the foreign antigens to defend the body against disease. The sensitized B-lymphocyte cells produce antibodies against the foreign proteins by clumping together, forming antibody-protein complexes that are ultimately destroyed by the body.

In an autoimmune disease such as SLE, the body mistakenly attacks healthy tissues by producing antibodies against itself (autoantibodies). The resulting antibody-protein complexes stick to surfaces and damage blood vessels in various parts of the body, such as the kidneys, causing organ damage. The B cells, which are normally responsible for immune response against antigens, therefore become over-aggressive and create an autoimmune response, which causes various symptoms.

Scientists found that there is a naturally occurring protein called B-lymphocyte stimulator, or BLyS, which when overproduced, can prolong the survival of B cells and increase the production of autoantibodies. These antibodies target the body’s own tissues, causing an autoimmune disease.

Benlysta was developed as a human monoclonal antibody that specifically recognizes and inhibits the biological activity of BLyS. Studies show that Benlysta can reduce autoantibody levels, which thereby helps control autoimmune disease activity. It is currently approved for the treatment of SLE, but more studies are being done to test its potential to treat other immune disorders like rheumatoid arthritis.

Just like other medications, Benlysta may have some adverse effects. Common side effects include fever, nausea, diarrhea, and hypersensitivity as well as infusion-site reactions. Treatment with an antihistamine before infusion of Benlysta is therefore recommended.

For more information, ask your doctor about Benlysta for SLE.