Erectile dysfunction (ED) has long been a disorder without a satisfactory treatment. The first biotech product to become available - Vivus Inc.'s MUSE alprostadil suppository - is far more appealing as a treatment than either the older vacuum devices and implants or the newer injectable alprostadil therapies.

As a result, VVUS (Menlo Park, Calif.), which began selling MUSE in January, posted $33.5 million in sales in the second quarter ended June 30, a 20 percent increase over the first quarter (see B16). Both quarters beat Wall Street estimates, despite a period of manufacturing problems at the company.

Nevertheless, VVUS's honeymoon may be short-lived, and MUSE may not have a clear market advantage for long. A variety of oral and topical products are in late clinical development and interviews with physicians indicate that these will be popular alternatives.

As a result, many clinicians expect that products such as MUSE and injection therapies may end up being niche products. In fact, given the variety of products likely to be on the market within the next few years, it seems unlikely now that any will be dominant.

On the bright side, newer, less painful therapeutic alternatives probably will increase the size of the ED market, and men may be willing to try a product like MUSE or injections as second-line therapy if they fail more palatable oral therapies.

About 140 million men worldwide suffer from ED of both organic and psychological origin. But according to physicians, only about 10 percent of them seek treatment. The problem is not that treatments don't work - clinicians say that most of their patients produce erections in response to currently available injectable agents. Rather, the issue appears to be related more to ignorance that effective treatments are available, embarrassment about seeking treatment, and the distastefulness of current therapeutic options.

Marketed injectable agents include The Upjohn Co.'s (Kalamazoo, Mich.) Caverject alprostadil (prostaglandin E1 and prazosin), an injectible launched in September 1995. Schwarz Pharma Inc. (Mequon, Wis.) received FDA approval in June to market Edex, its injectable alprostadil product for ED.

While reviews of VVUS's MUSE are mixed, physicians said they offer it to patients and expect that it will find a niche for itself even after oral therapies become available.

As is often the case outside the controlled clinical trial environment, MUSE's efficacy hasn't been as high in general use as it was in trials. However, according to the company, its sales force has been working with physicians on titrating doses and proper use of the product, and the company said it has seen improvements in efficacy with this effort.

David Ferguson
Consultant, Grayslake, Ill.

Ferguson is an emergency medicine and clinical pharmacology specialist, as well as a consultant to the drug industry in designing clinical trials for ED. The treatment outcome for ED, he said, is always based on multiple factors, both organic and psychogenic.