By MICHAEL REID and SUSANNAH
RODGERS DOW JONES NEWSWIRES LONDON -- GlaxoSmithKline PLC said Friday
that U.S. regulators approved Wellbutrin XL, a new version of a GSK
antidepressant whose earlier forms have been threatened by generic
competition. The U.S. Food and Drug Administration approved Wellbutrin
XL for treatment of major depressive disorder in patients aged 18
The approval has come slightly
earlier than expected and will enable GSK to get the drug into pharmacies
by mid-September. The new drug has two advantages for patients over
other treatments: It's taken only once a day and there is less risk
of side-effects, such as sexual function impairment and weight gain
-- common problems with other treatments.
Company insiders told Dow
Jones Newswires that GSK considers Wellbutrin XL to be one of its
two most important drug launches this year -- the other being impotence
treatment Levitra, GSK's answer to Pfizer Inc.'s multibillion-dollar
drug Viagra. Wellbutrin XL has two dosages, 150mg and 300mg. "We think
it has the potential to be a pretty big product," said one person
at GSK familiar with the company's drug strategy. "We're going to
put a lot of [sales] reps behind it."
For GSK, the approval is
a key step in helping it defend Wellbutrin against generic competition.
"Through the first half of 2003, our twice-daily formulation, Wellbutrin
SR, has remained the No. 1 prescribed antidepressant among U.S. psychiatrists,"
said Chris Viehbacher, GSK's president of U.S pharmaceuticals. "Yet
we know that for many doctors, twice-daily dosing is a major prescribing
barrier." GSK hopes physicians who would otherwise opt for the generic
companies' cheaper copies of the twice- and thrice-daily treatments
(when they eventually launch them), will instead put their patients
on the once-a-day XL version, even though it'll be more expensive.
Williams de Broe analyst Navid Malik said the approval means GSK's
Wellbutrin franchise looks "a little more stable than it did a few
months ago." "Glaxo can now invoke a Paxil/Paxil CR strategy," Mr.
Malik said, referring to GSK's attempt to defend its best-selling
antidepressant, Paxil, by introducing a controlled-release version.
Wellbutrin works differently from the more publicized class of antidepressants
known as SSRIs -- selective serotonin reuptake inhibitors -- including
Eli Lilly & Co.'s Prozac and GSK's own Paxil, and has different side
effects. Paxil, also known as Seroxat, brought GSK sales of £2.1 billion
last year. But it's also facing a possible generic threat. Like many
drug companies, GSK is desperate to extend the life of established
drugs by bringing out new, improved formulations with fresh patent
protection, thereby preserving exclusive selling rights. The industry
is at pains to milk established drugs for all their worth because
of the fierce challenge generic drug makers is presenting to the pharmaceutical
giants. Also, the big pharmaceutical companies are struggling to come
up with new, big-selling medicines to replace the blockbusters that
were the cornerstone of their earnings during the buoyant 1990s.