Drugmakers step up search for hearing loss medicines
ZURICH/LONDON:
When Swiss biotech firm Auris Medical wanted to recruit patients to
test its experimental hearing loss drug, it decided to enlist partygoers
deafened by firecrackers on New Year's Eve.
In
the weeks leading up to December 31, 2005 it advertised in the subway
and on radio stations in Munich and Berlin, urging victims of sudden
firecracker-induced hearing loss to turn up at designated clinics for
treatment on January 1.
"We had just one single day of enrolment,
we didn't know how many people would show up," Thomas Meyer, managing
director of Auris, told Reuters.
Luckily, his gamble paid off and
the small private company is now one of the leaders in what has been an
empty space for the pharmaceutical industry.
Auris managed to
recruit enough people to show that its compound AM-111 posed no safety
risk and has since successfully completed a mid-stage trial in acute
sensorineural hearing loss, or sudden deafness, involving 210 patients.
While
there is no guarantee that its drug, which is injected through the
eardrum, will pass muster in final-stage tests, the progress by Auris
and a clutch of rival biotech firms is making large pharmaceutical
companies sit up and take notice.
There are currently no approved
disease-modifying drugs for hearing loss, which affects nearly a third
of people aged 65 to 74 and half of those over 75.
But the science
is developing and investor interest is growing, piqued by the huge
commercial success of recent new treatments for sight loss, such as
Lucentis from Novartis and Roche and Eylea from Regeneron and Bayer.
British
charity Action on Hearing Loss conservatively puts the potential
Western market for new drugs at $4.6 billion a year - a figure that
could grow quickly as ageing populations swell the ranks of those with
hearing problems.
NEGLECTED FIELD
"It's one of the few areas
that, as yet, hasn't really been tackled by the drugs industry," said
Kate Bingham, managing partner at SV Life Sciences Advisers, a venture
capital firm with investments in new drugs for both eyes and ears.
Bingham
sits on the board of Autifony Therapeutics - a hearing loss firm spun
out of GlaxoSmithKline in which the British drugmaker retains a stake.
Historically,
hearing loss has received little attention from Big Pharma, given the
lack of obvious targets for drug intervention, the difficulties of
running clinical trials and a widespread belief that most deafness could
not be reversed.
Now the big companies are getting involved, although the work is early-stage.
"A
drug that is therapeutic and priced right could be quite a blockbuster.
That's why they've put their toe in the water," said Jonathan Kil,
chief medical officer at Seattle-based Sound Pharmaceuticals, which is
enrolling young iPod users in a trial of an oral drug for noise-induced
hearing loss.
U.S. giant Pfizer is arguably the most advanced of
the big players, with a drug in initial Phase I clinical testing trial
for age-related sensorineural hearing loss that looks to enhance the
function of existing hair cells.
Some of its biggest rivals are
laying bets, too. Last year French drugmaker Sanofi inked a two-year
research deal with privately held Dutch biotech firm Audion Therapeutics
to develop small molecule drugs to improve hearing.
In October,
Roche joined forces with venture capital firm Versant Ventures and
biotech Inception Sciences to find molecules targeting ear hair cell
protection and regeneration in the cochlea, the spiral-shaped cavity in
the inner ear.
Cross-town competitor Novartis, meanwhile, struck a
2010 deal potentially worth more than $213 million with U.S. biotech
GenVec to develop gene-based treatments to replace hair cells in the ear
that transmit sound.
"We're looking at restoration as our main
line of work and we're interested in whether there are chemicals that
might also play this role instead of having to introduce a gene," said
Novartis research head Mark Fishman.
"This is an area that's a bit more futuristic and ultimately restoring the hair cells will be the cure."
EYES AND EARS
Unlike
new eye drugs, which work by inhibiting an unwanted process, hearing
drugs will need to restore damaged function - a more difficult
proposition.
Experts say the first drugs will target niche areas, such as damage caused by loud noise or as a result of chemotherapy.
"Hearing
loss is not just one condition. It's like cancer - there are lots of
different types and there is work to be done to segment the market,"
said Ralph Holme, head of biomedical research at Action on Hearing Loss.
Heading
the field for noise-induced hearing loss is South Illinois University,
which has launched a late-stage trial with the U.S. military for an drug
to increase protection for people exposed to very noisy environments
like soldiers.
Canada's Adherex also has a late-stage trial to
test a drug that may protect against hearing loss caused by
platinum-based anti-cancer agents in children.
While protective
treatments could become available within the next few years,
regenerative approaches - such as injecting stem cells into the ear or
chemically intervening to switch on genes that control cell growth - are
much further off.
Despite recent promising tests in gerbils, the
potential to replicate this in humans is still uncertain, said Pascal
Senn, an ear specialist at the University of Berne.
"If something
grows inside the ear, you must be sure that it doesn't grow excessively
or form tumors. There are a lot of roadblocks that need to be overcome
in this field. It's highly risky, but I think it's also the hottest
area," he said.
One intriguing possibility for the future is the
convergence of future drugs and devices. Hearing aid manufacturers have
certainly not been deaf to the noises from the pharma sector.
Sonova,
the world's largest maker of hearing aids, has invested in two start-up
companies - one in the United States for drugs to protect hearing and
another Swiss biotech working on a treatment for acute tinnitus.
It
bought U.S. cochlear implant manufacturer Advanced Bionics in 2009 in a
bid to increase its focus on the inner ear and understand how drug
treatments could work with implants.
"It will be interesting
whether the innovation will be driven by pharma companies moving in or
whether the hearing aid companies will branch out," said Auris' Meyer.
(Reuters)
