government approved a novel drug Monday to help patients
with the AIDS virus who are running out of options,
while acknowledging lingering questions about the
pills' long-term effects.
Selzentry is the first anti-AIDS drug that works by blocking
a crucial doorway, called the CCR5 receptor, that HIV
often uses to enter white blood cells.
York--based Pfizer said the pill, known chemically as
maraviroc, would be available next month. A
spokeswoman said it would cost about the same as other
HIV medicines, roughly $900 a month wholesale.
It marks the
first in a new class of HIV medicines since 2003, when the
FDA approved an injectable ''fusion inhibitor'' that blocks
a slightly later stage of infection.
long known that people who naturally lack a working
version of the CCR5 doorway are somewhat resistant to HIV
infection, and slow to develop AIDS if they do become
infected. But the race to develop CCR5 receptor
blockers slowed with concerns that this family of drugs
might cause serious side effects, including liver or heart
damage and an increased risk of other infections or
The Food and Drug
Administration approved Selzentry after concluding that
certain hard-to-treat patients need the new
option--but is requiring Pfizer to conduct
further research to assess long-term side effects, said
Debra Birnkrant, the agency's HIV drugs chief.
For that select
group Selzentry's ''benefits clearly outweigh the
risks,'' Birnkrant said. ''That doesn't mean there aren't
The drug is not
for the newly diagnosed but only for patients whose virus
is fast becoming resistant to today's HIV drugs, she
also must get a blood test to ensure that the HIV
strain they have uses the CCR5 pathway. Doctors would send a
frozen blood sample to a San Francisco Bay
area testing company, Monogram Biosciences.
determined to have so-called 'R5 virus' would take the
twice-a-day pill in addition to their usual HIV drugs.
In a six-month
study where patients added either Selzentry or a dummy
pill to their regular medicine, Selzentry users were twice
as likely to have their virus levels become almost
unmeasurable, she said.
Topping the side
effect list is a stern warning that the drug may damage
the liver, with symptoms that may at first mimic an allergic
reaction. People who develop signs of hepatitis or an
allergic reaction should see a doctor immediately.
warned that studies counted more cardiovascular problems,
including heart attacks, in Selzentry users. Other side
effects include dizziness, upper respiratory
infections, and fever.
Pfizer said it
planned to use the brand name Celsentri outside the U.S.
The FDA forced a spelling change for fear of mix-ups with
similar-sounding drugs here, Birnkrant said. (AP)