Benlysta Approved (Finally) for SLE
I wrote about the "Belimumab Buzz" as a top 10 story of 2009. Now, some 14 short months later, the FDA announces its approval of the molecule, trade name Benlysta, for the treatment of systemic lupus erythematosus (SLE). The IV monoclonal antibody, developed by Human Genome Sciences and comarketed by GSK, is indicated for patients with active, autoantibody-positive SLE, who are already receiving standard immunosuppressive therapy (eg, corticosteroids). According to the Lupus Foundation of America, belimumab is the first treatment for SLE to be FDA approved in about 30 years.*
Belimumab approval is based on the results of 2, placebo-controlled, phase 3 trials involving a total of 1684 patients: BLISS-52 and BLISS-76. However, only the results of the former trial have been published in a peer-reviewed journal (last month in The Lancet).** A user-friendly tabulation of the non-peer-reviewed BLISS trial results can be found here. The major safety issues associated with belimumab appear to be serious infections and, to a lesser extent, infusion reactions. Notably neither trial enrolled patients with kidney or CNS involvement.
Another caveat, per the FDA: African Americans did not appear to respond to the drug; although the studies "lacked sufficient numbers to establish a definite conclusion." (About 3%-4% of enrollees in BLISS-52 were of Af-Am descent.) "To address this concern," the FDA continued, "the sponsor has agreed to conduct an additional study of people with those backgrounds to further evaluate the safety and effectiveness of Benlysta for this subgroup of lupus patients."
Belimumab acts by inhibiting the activity of B-lymphocyte stimulator (BLys), which otherwise promotes the survival of antibody-producing B cells. The drug's mechanism of action supports its use in autoimmune disorders, like SLE. The LFA estimates that there are about 1.5 million Americans with the disease.
Yesterday's approval was associated with a 12% spike in HGSI's share price: from 25.68 to 28.91.
* As previously written, even the almighty Rituxan (rituximab; Genentech/Roche) bit the dust in phase 3 studies of patients with SLE. And another recent great hope for SLE, CellCept (mycophenolate mofetil; Roche), died a death of noninferiority after it performed no better than cyclophosphamide for the induction treatment of lupus nephritis.
** Although the results of BLISS-76 have been reported.
