ROCKVILLE, Md. _ The FDA's Peripheral and CentralNervous System Drugs Advisory Committee Mondayvoted unanimously to recommend approval of BiogenInc.'s Interferon Beta-1A (Avonex) for treatment ofcertain types of multiple sclerosis.
Biogen's stock (NASDAQ:BGEN) closed at $59.25, up$6.50, or 12 percent, in trading of more than 6 millionshares.
A single clinical trial sponsored by the Cambridge,Mass.-based company at four centers found that Avonexclearly was efficacious in shortening the progression ofdisability when compared to placebo. Multiple sclerosisprogressed in 15 percent of the patients in the treatmentarm compared to 25 percent in the placebo arm, clearevidence of the "quantified effect on progression ofdisability," said Biogen's John Alam, medical director.The study also found the drug reduced the exacerbation ofsymptoms and number and volume of brain lesionsdocumented by magnetic resonance scans.
While the committee found the drug safe and efficacious,it did not believe that Biogen had adequate evidence tosupport extrapolating the evidence to support expandinglabeling beyond those patients with relapsing andremitting symptoms. If the expanded labeling had beenapproved, another 20 percent of the multiple sclerosismarket would have been made available to Biogen, saidStephen Reingold, vice president for research, at theNational Multiple Sclerosis Society.
Estimates of the prevalence of multiple sclerosis in theU.S. population range from 120,000 to 300,000,according to a spokeswoman for the National MultipleSclerosis Society.
If the FDA approves the advisory committee'srecommendation, multiple sclerosis patients will havetwo biotech drugs from which to select. Two years ago,Betaseron, an interferon beta-2 version, was the first drugapproved to treat multiple sclerosis. Its labeling alsorestricts use to remitting and relapsing multiple sclerosispatients. Because multiple sclerosis patients have amultiplicity of symptoms, neurologists typically useseveral therapies including prednisone to treat thesymptoms.
Biogen officials declined to indicate how they wouldprice the new drug, which may be more appealing tomultiple sclerosis patients because it is injected intra-muscularly once a week while Betaseron, developed byChiron Corp., of Emeryville, Calif., is injectedsubcutaneously daily, Reingold said. Betaseron, whichcosts about $10,000 annually, has never penetrated themultiple sclerosis market as initially thought because ofreaction at the site of injection and flu-like side effects, headded.
"But [Avonex] faces the same challenges as Betaseron,"said Reingold. "If the manufacturer can formulate a self-administered dose, price it below Betaseron and deal withside effects, it will be more attractive to managed carefirms," he told BioWorld Today.
Avonex has behavioral side effects similar to Betaseronincluding depression and seizures.
Biogen plans to conduct another clinical trial to test ifAvonex, like Betaseron, stimulates production ofantibodies which block the drug's effect after prolongeduse. The drug also will be tested at higher dosages, inpatients with greater disability and if its effect continueseven after therapy ceases.
Committee members wanted data about whether the drugwas effective for two or four years or perhaps lifelongtreatment.
"The data are too limited to draw any conclusions about asustained effect," said Biogen's Alam.
"The question is whether the effectiveness is maintainedfour years out," said Chris Gennings, assistant professorof biostatistics, at the Medical College of Virginia, inRichmond. "FDA needs the proper data . . . aboutwhether the drug builds antibodies," he said.
Panel members also indicated that they were satisfiedwith Biogen's use of video taped clinical assessments inthe studies.
"Efforts should be made to standardize this technique,"said Ira Shoulson, professor of neurology, at theUniversity of Rochester Medical Center, in Rochester,N.Y. Another panel member found the techniquescientifically valid because "there is proof that it workedbecause when the FDA pulled this patient out of thetabulations the results were not changed," said JustinZivin, professor of neuroscience at the University ofCalifornia, at San Diego. n
-- Michele L. Robinson Washington Editor
(c) 1997 American Health Consultants. All rights reserved.