By Lisa Seachrist
WASHINGTON — Berlex Laboratories Inc. and Chiron Corp. submitted additional data to the FDA to expand the use of their multiple sclerosis drug, Betaseron, to include patients who have entered a progressive form of the disease.
Approved for use in patients with relapsing and remitting multiple sclerosis in 1993, Betaseron (interferon beta-1b) now has shown it can delay progression of neurological deficits in a clinical study of 718 patients with secondary progressive multiple sclerosis (MS). Should the agency grant the company an expanded label, it will be the first product approved to treat that specific form of MS.
Biogen Inc.'s Avonex (interferon beta-1a) is also on the market for the treatment of MS; however, like Betaseron, to date it has only been approved for treatment of the relapsing-remitting form of the disease.
"This is the first time a beta interferon has shown efficacy in treating secondary progressive MS," said Jeffrey Latts, vice president of clinical research and development at Berlex, in Wayne, N.J. "What we are seeing is really the beginning of the products [Betaseron and Avonex] differentiating themselves. No other product has shown an effect in secondary progressive disease."
MS is a progressive, degenerative, autoimmune disease that disrupts the brain's nerve impulses and interferes with movement, speech, vision and memory. It is a highly variable disorder, which affects about 250,000 in the United States.
Approximately 80 percent of patients begin with a relapsing-remitting form of the disease, which is characterized by acute episodes of exacerbated symptoms followed by stable periods where symptoms abate to one degree or another. Nearly half of all patients who develop relapsing-remitting MS eventually enter a stage of steady progression of their disease, referred to as secondary progressive disease.
Berlex, the developer and marketer of Betaseron, and Emeryville, Calif.-based Chiron, the manufacturer of the drug, filed a supplement to their original biologics license application (BLA) to expand Betaseron's label following results of a multicenter, randomized, placebo-controlled clinical study conducted in Europe.
In that trial, 718 patients were given either 8 million units of Betaseron injections every other day or received placebo injections. The study was designed to last for three years, but an independent data monitoring board halted the trial after two years when it became clear Betaseron delayed progression of the disease by ninr to 12 months.
In addition, Betaseron prolonged the time until patients became wheelchair bound, decreased the number and severity of relapses and decreased the number of brain lesions visible by magnetic resonance imaging.
"Because the trial was stopped early, it is hard to characterize the treatment effect," Latts said. "But the nine- to 12-month delay is pretty unequivocal. It is a very meaningful result medically."
Analyst Expects Modest Sales Gain
Eric Schmidt, an analyst with Cowen & Co., in Boston, expects a new indication to help stem the loss of market share that Betaseron has experienced since Biogen's Avonex entered the market in 1996.
Schmidt noted that patients seem to prefer Avonex because it allows for once-weekly intramuscular injections as compared to Betaseron's every-other-day subcutaneous regimen. However, if Betaseron gets an expanded label, it may allow wheelchair-bound patients to be reimbursed for therapy.
"We are expecting sales to modestly improve," Schmidt said. "We project that Betaseron is going to continue to lose share in relapsing-remitting disease, but we expect it to gain market share in secondary progressive disease."
Schmidt said the study results were good news for Chiron, which has had a number of disappointments over the past two years.
Berlex is a U.S. subsidiary of Schering AG, of Berlin.
Chiron's stock (NASDAQ:CHIR) closed at $15.688, down $0.844. *