The 'Viagra' man
That was a `wow' moment," says Dr Peter Ellis, Pfizer's Executive
Director and joint patent-holder on Viagra, recalling 1993, when a
pilot study on 16 patients showed that sildenafil citrate (the
ingredient in Viagra) was indeed effective in erectile dysfunction (ED).
"Wow" led to "eureka", when it was found that a single doze was
effective and the side effects could be overcome. Then came the next
bout of doubt: Would the drug that worked in a controlled lab
environment work in a home environment too? And the response of one
patient on clinical trial says it all. "The patient was unwilling to
return unused drugs (after the trial). He knew that it would be years
before he would be able to buy a formal supply from the market,"
recounts Dr Ellis.
There were still several rounds of research to go before the drug
could be commercially launched in the market as Viagra. But that done,
it did not take long for Viagra to become a blockbuster drug, grossing
$1 billion in sales.
But how does it feel to be associated with a drug that is popular to
the extent that, ever so often there is a Viagra write-up, favourable
or otherwise, well researched or tongue-in-cheek? "Strange," he
replies and bursts into laughter. But then again, he adds, it has been
exciting. Exciting because the team of scientists achieved what they
set out to do.
"We set out to develop a PDE-5 inhibitor and we achieved it. Though it
did not work for the heart-indication that we proposed, it worked for
ED," he says. Exciting also because, till date, there are researches,
scientific papers and anecdotal reports emerging on alternate
indications of Viagra.
Put simply, Viagra is being used for heart-related problems in
infants. In fact, Pfizer has a sildenafil citrate drug Revatio to
treat pulmonary arterial hypertension (PAH), a rare, aggressive and
life-shortening vascular disease. There are reports that Viagra works
in fertility too. Anecdotal reports, unsupported by research, also
claim that it helps memory, he exclaims.
Dr Ellis wrote the research proposal on Viagra in 1986. He did have a
hunch in 1989 that the drug may work in ED, but it was only
two-and-a-half years later that the drug was worked upon for the
indication that finally raked in the moolah.
So did he make pots of money too on Viagra? "I have not received a
single rupee for Viagra," he guffaws and adds, "just the salary!"
It is not a one-man drug, he says, explaining that the team working on
the drug "explodes as it goes along." From being among just 15-odd
chemists and biologists in 1986, to 40 people in 1989 to 100 people in
1992, 300 people in 1994, 500 people in 1997 when the drug was being
filed for approvals etc and over thousands of people subsequently!
But did they ever guess they were sitting on something so big? "Not at
all... at least not at the beginning," he says. Taking head-on the
safety concerns around Viagra, Dr Ellis says: "Regarding the
cardio-vascular events, this drug does not have any link with the
heart-related problems that came up or the morbidity. And as for the
loss of vision, it comes and goes, it is transient," he says.
But Viagra has also been in the spotlight for NAION
(non-arteriticanterior ischemic optic neuropathy). "NAION is the most
common acute optic nerve disease in adults over age 50 and it shares a
number of common risk factors with erectile dysfunction: age over 50,
high blood pressure, high cholesterol, diabetes," says a Pfizer statement.
Dr Ellis adds emphatically there is no evidence showing that NAION
occurred more in men taking Viagra. Nevertheless, given the concerns
on side effects, the regulatory authority has asked for a caution
label on all drugs in this category, he says.
Viagra has two patents, a chemical molecule patent that expires in
2012 and a field-of-use patent in the US till 2019. Patents ward off
chemical equivalents that erode the sales of the original drug.
The original Viagra was launched recently in India, about five years
after the 15-odd desi-clones made their appearance. Product patent
protection has become effective in India only this year. Pfizer is now
looking at a drug for female sexual dysfunction, too, but Dr Ellis
points out that this will not be as simple as the drug for men and was
still some time away.
Reflecting on life with and around Viagra, he admits he is known as
the "Viagra man" in certain circles, but there are several people who
do not know him that way too. Being associated with Viagra has helped
people open up to him and say things they may not have said at other
times. In one such instance, Dr Ellis got Viagra to help a couple, but
not in the known indication. "I do know a couple who were able to bear
a child after the woman took Viagra to address a fertility problem,"
he says, happy with the ever-unfolding list of indications for
sildenafil citrate. Dr Ellis now pursues other interests in obesity
andurology, as well.