BENLYSTA (belimumab) was granted a priority review by the FDA as a potential treatment for systemic lupus erythematosus (SLE).

The experimental drug is produced by Human Genome Sciences, Inc. and GlaxoSmithKline PLC (GSK).

A priority review designation is granted to drugs that, if approved, offer major advances in treatment or provide a treatment where no adequate therapy exists. The FDA has assigned belimumab a Prescription Drug User Fee Act (PDUFA) target date of December 9, 2010.

SLE is a chronic, inflammatory autoimmune disorder that may affecr the skin, joints, kidneys, and other organs. A majority if patients with SLE have joint pain and many go on to develop arthritis. Joint affected are usually in the fingers, handsm wrists, and knees. Occasionally, inflammation of the heart may occur as well as chest pain and arrhythmias.

Some symptoms include fatigue, fever, joint pain and swelling, muscle aches, nausea and vomiting. Some treatments include NSAIDs for arthritis and corticoid creams for skin conditions.

BENLYSTA works by inhibiting the biological activity of B-lymphocyte stimulator, or BLyS. BLyS is a naturally occurring protein required for the survival and development of B-lymphocyte cells into mature plasma B cells. Plasma B cells produce antibodies. Elevated levels of BLyS are believed to contribute to the production of autoantibodies. The results of prospective observational studies show a significant correlation of elevated levels of BLyS with SLE disease activity

BENLYSTA recognizes and bindsto BLyS. It inhibits BLyS’s stimulation of B-cell development and restores the potential for autoantibody-producing B cells to undergo the normal process of apoptosis.

The Biologics License Application (BLA) for belimumab was submitted to the FDA on June 9, 2010, and includes the results of two pivotal Phase 3 clinical trials. The trials treated a total of 1,684 autoantibody-positive patients with SLE. Human Genome Sciences designed the Phase 3 program for belimumab in collaboration with GSK and international SLE experts, in consultation with the FDA.

“We are very pleased that FDA has chosen to grant priority review to belimumab, the first in a new class of drugs called BLyS-specific inhibitors,” said H. Thomas Watkins, President and Chief Executive Officer, HGS. “We believe that the priority review designation speaks both to the significant medical need of people living with lupus and to the potential belimumab may hold as a new treatment option for these patients.”

Carlo Russo, M.D., Senior Vice President, Biopharm Development, GSK, said, in a press release, “Belimumab is the first medicine for lupus that has completed Phase 3 trials with positive results. We look forward to continuing to work together with HGS to progress regulatory files and we hope that we will be able to deliver a new treatment option for patients living with lupus.”