Tuesday March 12, 4:18 PM EST
By Toni Clarke
NEW YORK, March 12 (Reuters) - Biogen Inc. (BGEN) launched the first salvo in its battle to protect multiple sclerosis drug Avonex from competition in the United States by asking regulators to stop Serono SA (SEOZ) from claiming its rival drug is superior.
Biogen on Tuesday said the U.S. Food and Drug Administration told it Serono, Europe's biggest biotechnology company, could not say its drug Rebif is superior to Avonex because whatever advantage Rebif has was based on "limited findings from a short-term study."
The FDA, however, denied Biogen's statement and said the biotechnology company's claim that the agency had agreed to "take enforcement action" against Serono if it made claims of superiority for its drug was "wrong."
Cambridge, Massachusetts-based Biogen's statement comes as it attempts to defend the dominant position of Avonex in a market it estimates could reach $4 billion by 2005. Avonex generated worldwide sales of $972 million in 2001 and is Biogen's only marketed product.
The FDA last week abolished the protection from competitors Avonex has enjoyed under a rule designed to promote drug development for diseases with small populations. To overturn Avonex's so-called orphan drug status Serono had to show that Rebif was either safer or more effective than Avonex.
Biogen said the FDA's chief legal counsel told it he would take action against Serono if the company tried to make a general claim that Rebif was a superior to Avonex.
Dan Troy, the FDA's legal counsel, said through a spokeswoman that he had made no such statement and that he was "not happy" about Biogen's public exploitation of a private telephone conversation.
"All he said was that he would look at promotional materials," the FDA spokeswoman said. "He made no commitment to doing anything further."
The FDA ruled last week that on the basis of a six-month head-to-head study, patients on Rebif suffered fewer relapses than those on Avonex. FDA investigators in documents posted on its Web site note that Rebif maintains its advantage over Avonex after 48 weeks.
Investigators, summarizing their reasons for approving Rebif's launch, said the FDA "has fully evaluated these issues and has determined that Rebif is clinically superior to Avonex."
Figures on the Web site show that over 48 weeks, 62 percent of patients on Rebif remained relapse-free compared with 52 percent patients on Avonex.
Biogen argues that the 48-week data, not previously released by Switzerland-based Serono, show Rebif's advantage over Avonex dwindling over time. While the overall figure for the year shows Rebif to be more effective, the company says, the advantage of Rebif dwindles away in the second 24-week period.
In weeks 0 to 24, 75 percent of patients on Rebif were relapse-free compared with 63 percent on Avonex, data posted on the FDA's Web site shows. In weeks 24 to 48, however, 82 percent of patients on Rebif were relapse-free compared with 83 percent on Avonex.
"Rebif shows clinical superiority on one measure over 24 weeks, but they cannot claim that Rebif is a better drug than Avonex," said Kathleen O'Donnell, a Biogen spokeswoman. "At 48 weeks you see the lines start to narrow."
Carolyn Castel, a Serono spokeswoman, said Biogen's parsing of the data is "irresponsible" and "disgraceful."
"The FDA observed that at 48 weeks the treatment advantage of Rebif was maintained," she said.
Doctors say they are unlikely to switch patients en masse from Avonex, which currently has about 60 percent of patients on multiple sclerosis treatments in the U.S., to Rebif. But they may well put new patients on Rebif.
Avonex is effective, doctors say, and has some advantages over Rebif in terms of convenience. Rebif must be injected three times a week, while Avonex needs to be injected once a week. Avonex is also as much as 30 percent cheaper than Rebif, which is administered in higher doses.
Still, Rebif, which is sold alongside Avonex outside the United States, has proven to be a formidable competitor. It holds the leading share of the market -- 38 percent -- outside the United States. The company aims to capture 25 percent of the U.S. market by 2005.
Biogen's shares rose 10 cents to $50.49. Serono's shares fell 2.7 percent
to 1,435 Swiss francs on the Swiss Market Index.
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