belimumab (Benlysta)

Belimumab is a synthetic (man-made) injectable antibody that reduces the activity of immune cells called B-cells in patients with systemic lupus erythematosus (SLE). SLE is an inflammatory autoimmune disease, which means that the body's immune system attacks its own tissues and causes inflammation. Parts of the body affected by SLE include the heart, skin, joints, kidneys, lungs, and brain. Common symptoms include rash, fever, chest pain, hair loss, joint pain, fatigue, and sensitivity to light.

One type of immune cell that is involved in the immune attack in SLE is the B-cell. One of the functions of B-cells is to produce antibodies, proteins that the body usually produces to fight infection. The B-cells in SLE produce antibodies that may be involved in the autoimmune attack in SLE. Belimumab blocks the action of B-cell (lymphocyte) stimulator (BLyS) protein, which B-cells require for survival. By blocking BLys, belimumab reduces the number of B-cells available to produce antibodies that contribute to SLE. In clinical studies, belimumab-treated patients experienced less activity of their SLE than those who received other SLE therapies. Belimumab was approved by the FDA in March 2011.

What brand names are available for belimumab?

Benlysta

Is belimumab available as a generic drug?

No

Do I need a prescription for belimumab?

Yes

The most common adverse reactions of belimumab are:

• nausea,
• diarrhea,
• vomiting,
• stomach pain,
• fever,
• stuffy or runny nose,
• cough (bronchitis),
• insomnia,
• leg or arm pain,
• migraine, and sore throat.

Other important side effects of belimumab include:

• allergic or infusion-related reactions such as itching; swelling of the face,
• lips,
• tongue, mouth, or throat as well as
• difficulty breathing,
• low blood pressure,
• dizziness,
• fainting,
• rash,
• redness, or
• swelling of the skin.

Infections, heart problems, depression, and suicide have also occurred in patients taking belimumab. Like other drugs that reduce the activity of the immune system, belimumab may increase the risk of certain cancers.

The recommended dose of belimumab is 10 mg/kg at two-week intervals for the first three doses and at four-week intervals thereafter. Belimumab is administered intravenously over a one-hour period.

Drug interactions have not been studied. Since belimumab reduces the activity of the immune system it may interfere with the response to immunizations. Live vaccines should not be administered concurrently with belimumab or at least 30 days before administration of belimumab.

Belimumab has not been adequately studied in pregnant women. Belimumab can cross the placenta. A pregnancy registry has been established for monitoring the safety of belimumab in pregnant women. The number for the registry is 1-877-681-6296.

It is not known whether belimumab is excreted in human breast milk. Since antibodies are usually excreted in breast milk, mothers should consider not breastfeeding or discontinuing belimumab if they want to breastfeed.

What preparations of belimumab are available?

Lyophilized powder for reconstitution: 120 mg (5 ml) and 400 mg (20 ml) single-use vials

How should I keep belimumab stored?

Belimumab should be refrigerated between 2 C-8 C (36 F-46 F). It should not be frozen or exposed to heat. Vials should be stored in their original carton and protected from light.