Belimumab

Monoclonal antibody- Belimumab

Belimumab (brand name: Benlysta) is a drug that uses monoclonal antibodies to treat patients with systemic lupus erythematosus (SLE).  Monoclonal antibodies use hybridomas, a fusion of B cells and myeloma cells. This hybrid can produce antibodies like B cells and also divide indefinitely like myeloma cancer cells so it’s like taking the best of both worlds. They are called “monoclonal” because the antibodies come from clones of one parent cell. Belimumab helps patients with SLE by creating antibodies that block the B-cell lymphocyte stimulator (BLyS) protein; blocking the protein decreases the number of B-cells.

Side-effects of the drug

Why decrease the number of B-cells? SLE is an autoimmune disease where the patient’s B-cells produce antibodies that attack healthy tissue. Symptoms of SLE include sun sensitivity, swelling, and a butterfly-shaped rash around the cheeks and nose. Most people with lupus can have a normal lifespan because the availability of treatments like Belimumab. But, Belimumab has complications of its own. The most common side-effects of Belimumab include: nausea, diarrhea, vomiting, stomach pain, fever, runny nose, cough, insomnia, limb pain, migraine, and sore throat. Some of these symptoms slightly overlap with those of SLE like joint pain. The additional side-effects include: swelling of the face, lips, tongue, mouth, throat, or skin, difficulty breathing, low blood pressure, dizziness, fainting, rash, and redness. All the possible inconveniences the drug may bring can be worth it though because without the drug, people with lupus can die from complications with the heart or kidney.

Regulatory submissions in 2020

The drug impacts the acquired response negatively by reducing the number of B-cells. Since the drug decreases the number of B-cells available, patients cannot receive live vaccines in fear of getting infected. In addition to infections, the drug increases the risk of certain cancers. Some patients taking Belimumab have reported signs of depression and suicide. With all these possible side-effects, does Belimumab really improve life for lupus patients? According to a BLISS-LN study, yes. The study showed a response rate of 43% and statistical significance compared to a placebo- taking Belimumab can improve the life of patients suffering from SLE despite the risk of other symptoms. Belimumab is on track for regulatory submission.