Human Genome Sciences, Inc. (HGSI) and GlaxoSmithKline Plc (GSK,GSK.L) said Monday that Benlysta, or belimumab, met its primary endpoint in the second of its two pivotal Phase 3 trials in seropositive patients with systemic lupus erythematosus, or SLE. The companies plan to submit marketing applications in the first half of 2010, following discussions with regulatory authorities in the US, Europe and other regions.
The data through 52 weeks of the study, named BLISS-76, achieved a statistically significant improvement in patient response rate compared with placebo plus standard of care. Belimumab was generally well tolerated, with overall adverse event rates comparable between belimumab and placebo treatment groups.
The study evaluated patient response rate based on the SLE Responder Index, or SRI, to achieve clinically important reduction in SLE disease activity, no worsening of disease as measured by the Physician's Global Assessment, and no clinically significant BILAG worsening.
In the current study through 52 weeks, belimumab 10mg/kg plus standard of care showed statistically significant improvement over placebo, while 1 mg/kg dose plus standard of care did not. However, the BLISS-76 study is ongoing and will continue for 24 more weeks. Additional data will be available following completion of the full 76-week study period.
SLE is a chronic, life-threatening autoimmune disease, with no FDA approved medicine since 50 years. Around 5 million people worldwide, including approximately 1.5 million in the United States, suffer from various forms of lupus, including SLE. Lupus can lead to arthritis, kidney failure, heart and lung inflammation, central nervous system abnormalities, inflammation of the blood vessels and blood disorders.
Belimumab is an investigational drug and the first in a new class of drugs called BLyS-specific inhibitors. Benlysta is a fully human monoclonal antibody that specifically recognizes and inhibits the biological activity of B-Lymphocyte stimulator (BLyS). In lupus and certain other autoimmune diseases, elevated levels of BLyS are believed to contribute to the production of autoantibodies.
Benlysta is given FDA's Special Protocol Assessment, which enables review of uncompleted Phase III trial's design, clinical endpoints, and statistical analyses for FDA approval. In August 2006, Human Genome and GSK entered into an agreement for co-development and commercialization of belimumab.
Phase III development program for belimumab included two double-blind, placebo-controlled, multi-center Phase 3 superiority trials - BLISS-52 and BLISS-76, with similar design but different duration. Earlier in October, BLISS-52 demonstrated statistically significant improvement in patient response rate when compared with placebo.
BLISS-76 is a 76 weeks, randomized treatment enrolling 819 patients at 136 clinical sites in 19 countries, primarily in North America and Europe. Data from BLISS-76 were analyzed after 52 weeks in support of a potential Biologics License Application in the United States and Marketing Authorization Applications in Europe and other regions.
"The results from this second pivotal Phase 3 trial reinforce our belief that belimumab could deliver a significant therapeutic option for patients with lupus who have had no new treatment in fifty years," said Carlo Russo, M.D., Senior Vice President, Biopharm Development, GSK.
Among other drugs being developed for SLE, Immunomedics, Inc. (IMMU) is developing UCB's epratuzumab and Wyeth is developing SBI-087 of Trubion Pharmaceuticals, Inc. (TRBN).
Friday, HGSI closed regular trading at $18.69, on the Nasdaq and GSK finished at $41.16, on the NYSE.
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