PFIZER EXPLORES TREATMENT FOR IMPOTENCE : TRIAL PILL OFFERS PROMISE OF RESTORING MEN'S SEXUAL FUNCTION.

Byline: Ron Winslow Wall Street Journal

A new experimental drug is raising hopes that, for the first time, men one day may be able to take a pill to treat one of their most confounding health problems: impotence.

The debilitating and often hidden diagnosis afflicts untold millions - researchers can only guess at the total because so many men are reluctant to report the problem. For years treatment was limited to invasive mechanical devices. Researchers turned to drug therapy a decade ago, but current approaches require injections into the penis just before intercourse - not exactly an appealing proposition, in romantic or marketing terms.

New promise for a pill arose a few years ago, entirely by accident. Pfizer Inc.'s British research operation had developed a drug for angina, the chest pain that is a precursor to heart attacks. In initial experiments the drug, known as UK 92,480, proved to be a weak heart remedy, but participants reported an unexpected side effect: improved erections.

Researchers began exploring the drug's potential as a treatment for impotency and have launched a large-scale, world-wide study that will involve 2,500 patients who will take the pill for as long as a year - the final phase of testing before seeking federal approval to market the drug. The results of three earlier trials involving a smaller sample, to be unveiled today, offer a striking promise, suggesting the medicine helps restore sexual capacity in more than 80% of men who were unable to engage in sexual relations.

Much more research is needed to determine how effective the drug might be and who would benefit. Even if it works, the pill isn't expected to reach the market for at least two years. But if the initial promise is confirmed, urologists say the pill would have a major impact on a condition that often quietly erodes men's self-confidence and can wreck relationships with their partners.

``Men have seen impotence as a personal, moral and psychological failure,'' says Abraham Morgentaler, director of the male infertility and impotence program at Beth Israel Hospital in Boston. Doctors blame that on the landmark Masters & Johnsons study of sexual behavior in the 1960s, which described impotence as a mental, rather than physical, problem. Dr. Morgentaler had a patient who was in psychotherapy for 20 years because of his impotence, ``when in fact what was wrong was that part of his body had failed him,'' he says.

When word leaked out over a year ago in Britain, where Pfizer's research effort is based, that the drug was being developed, the company received some 200 letters from men suffering from the condition. Some provided intimate details of ruined marriages or fears of losing their mates; others simply lamented that they were no longer able to make love with their wives.

``If the letters we get are anything to go by, there are a lot of people devastated by this condition,'' said Ian H. Osterloh, a Pfizer researcher leading the effort.

Urologists in the U.S. estimate that 20 million American men are impotent, although they acknowledge that reliable numbers are difficult to come by. The market could offer blockbuster potentials as Baby Boomers head into their 50s; doctors say that 15% of men in their 50s and one-third of those in their 60s have trouble with erections.

Impotence is particularly common among male diabetics, affects many men with high blood pressure and heart disease and sometimes is a complication of prostate surgery. And it is, indeed, caused in some cases by anxiety and other psychological factors. In one of the early studies being announced today, researchers found that almost 40% of men who took a placebo nonetheless reported improved erections.

In current drug therapy, direct and well-timed injections must be used to deliver high-enough concentrations to work. Pharmacia & Upjohn Co. markets Caverject, a therapy involving injection of the drug alprostadil through small needles into the side of the penis. ``It's an easy technique ... with relatively little pain,'' said Perry Nadig, a urologist in San Antonio, Texas. A recent study found 86% of patients were satisfied with the results.

Still, about 50% of those taking injections quit within a year. ``It just isn't something that provides much romantic-fantasy appeal,'' said Dr. Morgentaler of Beth Israel Hospital. ``Everyone would love a pill to treat erection problems.''

The trial results for Pfizer's new pill, a chemical named sildenafil that carries the brand name Viagra, are to be discussed today at the American Urological Association's annual meeting in Orlando, Fla. In the largest study, 351 patients were randomly assigned to a placebo or doses of as much as 50 milligrams of the drug for 28 days. The higher the dose, the higher the portion of men reporting more frequent arousals and higher sexual satisfaction. In the 50-milligram group, 88% of patients reported improved results.

Still, the results require a bit of faith: Researchers relied on patients' own assessment of whether the treatment improved their condition, rather than objective observation. They used a 15-point questionnaire, diaries and, for more than half the cases, separate written comments from the participants' mates.