A New Drug Treatment Approved for Lupus

On March 9 the Food and Drug Administration (FDA) approved Benlysta, the first new drug approved for the treatment of lupus in 56 years. While there are several types of lupus, I will use the term as an abbreviated name for systemic lupus erythematosus (SLE), an autoimmune disease caused by an attack of the body’s immune system on its own tissues that results in chronic inflammation.  How does this latest drug help?  Let's look at some background.

Prevalence and manifestations of lupus

Estimates of the prevalence of lupus among Americans vary from a low of about 320,000 to as many as a million. Women are affected nine-times more commonly than men. The disorder may begin at any age, but most often occurs in people between the ages of 10 and 50. Lupus is more common in African Americans and Asians than in Caucasians.

Lupus can be either mild or severe enough to cause death. In most people the disorder produces mild to moderate symptoms that may develop slowly or occur suddenly.  A common feature of lupus are flares, periodic episodes when its signs and symptoms worsen for a while and then may improve or even disappear completely for a time.  Lupus affects many tissues and organs, especially the skin, joints, kidneys, and nervous system. Common symptoms include:

• Pain, stiffness and swelling of joints
• Butterfly-shaped rash covering the cheeks and bridge of the nose
• Fatigue
• Fever
• Weight loss
• Skin lesions that may appear or worsen with exposure to the sun
• Hair loss
• Dry eyes
• Easy bruising
• Raynaud's phenomenon: fingers and toes turn white or blue when exposed to cold
• Shortness of breath
• Chest pain
• Anxiety
• Depression
• Memory loss

Treatment

Because there is no cure for lupus, treatments are aimed at controlling symptoms and preventing the progression of tissue damage. The type of treatment depends on the severity of the symptoms. For example, fever and mild to moderate arthritis can be treated with nonsteroidal anti-inflammatory medications (NSAIDs) and steroid creams are used for skin lesions. Drugs used for more severe manifestations of lupus include oral steroids such as prednisone, antimalarials like hydroxychloroquine, and the immunosuppressive medications methotrexate, azathioprine, and cyclophosphamide.

Benlysta (belinumab)

Benlysta reduces the activity of the immune system.  It does this by inhibiting the action of a protein which stimulates the production of B-lymphocytes.  Abnormal B-lymphocytes are thought to promote the tissue-damaging effects of lupus. Since the B-lymphocyte-stimulating protein was discovered by examining a collection of human genes, Benlysta is one of the first and few practical benefits reaped from mapping the human genome.

Clinical trials compared patients taking standard lupus medications plus placebo with those taking the same medications plus Benlysta. Patients treated with Benlysta experienced fewer disease manifestations than those who received the placebo.  When given by intravenous infusion every four weeks, however, the drug produced only modest clinical benefits in these trials. And there are other downsides to its use:

• Common side effects included nausea, diarrhea, fever and infusion reactions.
• There were more deaths and serious infections as might be expected with a drug that interferes with the immune system.
• African Americans did not appear to respond to the drug in the available trials.
• High cost: estimated at $30,000 a year or more.

Nonetheless, Benlysta is considered a valuable new addition to existing medications for the management of signs and symptoms associated with lupus.