INTERVIEW-XenovaPAIs have Prozac potential
Reuters Story - February 18, 1998 06:34
By Jonathan Birt
LONDON, Feb 18 (Reuters) - British biotechnology company
Xenova Group Plc said on Wednesday a new class of blood
clot-inhibiting drugs to be developed with Eli Lilly & Co
had the potential to be blockbusters in the Prozac
class.
"If you look at the potential population and multiple
indications, we have the numbers that could mean a multi-billion
dollar product," chief executive officer Louis Nisbet told
Reuters in a telephone interview.
Earlier, Xenova announced a partnership with Lilly to
develop drugs known as PAI-1 inhibitors which they believe will
prevent blood clots from forming without provoking excess
bleeding associated with existing treatments.
The drugs would be targeted principally at daily
preventative use by individuals who have survived heart attacks
-- an estimated 13 million people in the U.S. alone -- and take
on blood clot warhorses such as Warfarin and aspirin.
However Nisbet said use in patients with unstable angina,
ischaemic stroke, atrial fibrillation and deep vein thrombosis
could add another six million possible users in the U.S.
Pointing to the annual $2.6 billion of sales notched up by
Lilly's anti-depressant Prozac last year, Nisbet said: "The PAIs
have the potential to generate sales of that order of
magnitude."
Nisbet said Lilly had been one of a number of top 10
pharmaceutical companies that had expressed interest in
developing PAIs, which are based on chemicals from a microbe
found in soil.
"We were looking for someone like Lilly -- they are
approaching $400 million cardiovascular sales and want to build
that franchise, and this could propel their position to match
their position in CNS (central nervous system), anti-infectives
and so forth," he added.
Although Lilly is not yet a major player in cardiovascular
drugs, the company has licensed a successful blood clot
inhibitor, ReoPro, from Centocor Inc . Sales of ReoPro,
which is injected, jumped by 70 percent last year to $254
million.
ReoPro is used in angioplasty, surgery to treat narrowed
arteries. Nisbet said it would therefore not compete directly
with an oral PAI (plasminogen activator inhibitor) treatment,
which would be prescribed by general practitioners.
Nisbet said there was little competition in the
anti-thrombotic area.
A successful PAI drug would be pitted against the only
existing oral drugs used to control blood clots: aspirin, which
Nisbet said was effective in only around 20 percent of people,
and Warfarin.
Warfarin was launched by DuPont/Merck in 1954 and has been
the mainstay for prevention of blood clots ever since. Sales of
the drug, which is long off-patent, totalled around $700 million
last year.
However Nisbet said Warfarin had a slow onset of action and
a narrow range between giving an effective dose and a toxic
dose. It can react adversely to other drugs and certain foods
and vitamins, and patients have to be carefully monitored.
Development of PAIs was undertaken by Xenova scientists in
Britain. The next stage of development will pass to Xenova's
Californian subsidiary MetaXen, with Lilly picking up the
clinical work and responsibility for regulatory approval.
Lilly will pay Xenova up to $35 million in licence fees,
research funding and other payments when key stages in the
development work are passed. Xenova would also receive
undisclosed royalties on any products which eventually reach the
market.
Nisbet said Xenova was well ahead in the field of PAI drugs,
and was building a strong patent position.
"With Lilly our intention is not only to push our lead
forward but to block others through defensive patent work," he
said.
The company, which bases drug discovery on a huge library of
natural compounds derived from micro-organisms such as fungi,
bacteria and plant extracts, is also working on PAI-related
drugs in cancer, where it believes the protein plays a part in
the way the disease spreads.
Nisbet said Xenova would push these projects further through
development on its own before seeking partners. |
