From Nature:
For more than 50 years, the autoimmune disease lupus has confounded drug developers. But a new therapy finally broke through that barrier yesterday when the US Food and Drug Administration (FDA) announced the approval of Benlysta (belimumab) for the treatment of systemic lupus erythematosus. The greatly anticipated move heralded a step forward not only for belimumab's developers, but also for the many other experimental lupus therapies hot on the trail. “It's a very exciting time in lupus,” says Richard Furie, a rheumatologist at the North Shore-Long Island Jewish Health System in New York, who has conducted clinical trials of belimumab. “There's an awful lot of activity right now.”
Lupus is a mysterious disease in which the immune system attacks healthy tissues. Nearly all lupus patients experience some degree of joint pain, and some will face life-threatening complications including kidney failure, heart problems and difficulty in breathing. Belimumab is an antibody that interferes with the immune system's assault by binding to and inhibiting a protein called the 'B-lymphocyte stimulator' (BLyS). Blocking BLyS is thought to cause the immune system's antibody-producing B cells to self-destruct, thereby reducing the body's ability to attack its own tissues.
More here.