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.

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