(Adds analyst comments, background, byline, updates share
By Deena Beasley
LOS ANGELES Oct 29 Biogen Idec Inc (BIIB.O)
said on Wednesday that it has notified regulators of a new case
of a potentially deadly brain disease in a multiple sclerosis
patient being treated with Tysabri in the United States.
The company's shares fell about 12 percent in after-hours
"This creates a further overhang on the stock. It's
inevitably going to worry investors about what's around the
corner and it's just too early to know what the true rate is
for PML with Tysabri in commercial use," said Jim Birchenough,
an analyst at Barclays Capital.
Biogen and marketing partner Elan Corp Plc ELN.I said in
July that two new cases of the brain infection, known as
progressive multifocal leukoencephalopathy (PML), had emerged
They were the first PML cases to be announced since Tysabri
was withdrawn from the market in 2005 after three patients
developed the brain infection.
The drug returned to the market in 2006 with warnings after
the U.S. Food and Drug Administration decided MS patients
willing to accept the risks should be able to have access to
the drug's potential benefits.
"Since the last two cases were disclosed we've had about
3,000 patients on the drug -- about 1,000 a month ... I think
every case that comes along next will have minimal impact as
long as that rate stays about 1 in 1,000," said Cowen & Co
analyst Eric Schmidt.
But Birchenough said Tysabri sales trends are sensitive to
even a single case of PML and there is concern that physicians
may hesitate to start new patients on the drug.
"The problem for Biogen is this is their only growth
driver," he said.
Biogen said last week that 35,000 patients worldwide were
being treated with Tysabri and it continued to expect that
100,000 patients will be taking the drug by 2010.
Tysabri also won U.S. approval this year to treat adults
with moderate to severe Crohn's disease who have had a poor
response to, or cannot take, other therapies.
Shares of Biogen, which fell 41 cents to close at $41.94 on
Nasdaq, were lower at $37.00 after hours.
(Additional reporting by Bill Berkrot; Editing by Bernard