Another erectile dysfunction study came up short for MacroChem Corp., which saw its stock absorb a loss in the immediate aftermath.

Shares in the Lexington, Mass.-based specialty pharmaceutical company fell 20.6 percent Thursday - the stock (NASDAQ:MCHM) dropped 35 cents to close at $1.35. The reaction followed the release of preliminary Phase II data showing that MacroChem's Topiglan topical cream failed to meet the pharmacodynamic study's primary clinical endpoint - a measure of penile rigidity over a full dosing period of about an hour.

The study, which used the RigiScan monitoring technique, compared the efficacy of Topiglan in 34 men with mild to moderate erectile dysfunction to a placebo cream. Conducted at four sites - three in the U.S. and one in the UK - the trial's results revealed the drug's effects to be comparable to that of placebo.

"This was a new cream formulation, and we needed to design an objective test that would give us some good information for decision making, as to whether or not to move forward," MacroChem CEO Robert DeLuccia told BioWorld Today. "This particular test was designed to do just that."

He said the company would further analyze data over the next couple of weeks before drawing a final conclusion as to the product's direction.

"Now the decision is on us as to whether to go into the next trial, which is a very large, in-home trial with about 500 couples and subjective endpoints," DeLuccia added. "That's a multimillion-dollar trial, and the question is, Do we want to go forward with that?' That's a decision we need to make as a company."

The setback is not the first related to the product. Two-and-a-half years ago, the company reported a failed Phase III trial of Topiglan in a gel formulation, which resulted from dosing issues and a missed endpoint. That news cut in half MacroChem's stock, though at the time the company seemed to remain committed to advancing the product's development. (See BioWorld Today, Sept. 7, 2001.)

The drug's active pharmaceutical ingredient is alprostadil, a synthetic version of a hormone found naturally in human semen. The latest trial cost about $1.5 million, DeLuccia said.

"When you see those kinds of results, you say to yourself, There's no suggestion of efficacy here,'" he added. "However, we did find that it was relatively well tolerated, which was one of our objectives in reformulating this to a cream."

MacroChem reported about $7 million in cash reserves as of Dec. 31, a figure that has been bolstered by a $7.3 million financing raised last month. DeLuccia said this year's burn would range between $650,000 and $700,000 per month.

Among its costs going forward are clinical programs for two other products. The company is conducting a dose-proportionality study of Opterone cream, an absorption-enhanced topical treatment for male testosterone deficiency, and results are expected later this year. Patient screening is nearly complete in a Phase I study of EcoNail in patients with onychomycosis, a fungal infection of nails, with data expected to be available by the end of the year as well.

"As a company, MacroChem has a portfolio of products," DeLuccia said. "So when you run into challenges like this with one product, the other two absorb that and you move them forward. Both of those products are in large and growing markets."

Along with Topiglan, Opterone and EcoNail employ MacroChem's drug-absorption enhancement technology, SEPA (soft enhancement of percutaneous absorption). Another MacroChem technology, MacroDerm, is designed to retard skin absorption of certain chemicals. Along with academic collaborators, the company is evaluating its use in conjunction with an insect repellant and for other dermatological indications.