MacroChem Corporation announced that it is expanding a double-blind Phase 2 clinical trial of Topiglan, its easy-to-apply topical cream for erectile dysfunction (ED), into the United States. Trial sites in the U.S. will follow the same protocol as that of an ongoing trial in the United Kingdom, where this innovative treatment is being tested in men with mild-to-moderate ED. Topiglan combines alprostadil, a well-proven vasodilator, with SEPA, MacroChem's patented drug-absorption enhancer.

"Recent news of the imminent availability of Levitra in the U.S. will heighten awareness of available therapies as well as their limitations," explained Robert J. DeLuccia, president and chief executive officer of MacroChem. "Many patients and their physicians are concerned about the risks of drug-drug interactions and systemic side effects of the oral ED medications. We believe both doctors and patients will be attracted to a truly topical, easy-to-apply, locally acting alternative like Topiglan."

"The alprostadil in Topiglan is different from the active ingredients in the oral 'PDE-5 inhibitor' ED drugs," DeLuccia said. "Alprostadil alone isn't adequately absorbed when applied locally, and must be either injected or inserted into the urethra as a suppository. SEPA in Topiglan facilitates penetration of alprostadil through skin and into erectile tissues."

MacroChem believes that a truly topical alprostadil formulation could theoretically offer significant advantages over oral ED medications. Those advantages include no significant systemic side effects; rapid onset of action; and low risk of systemic interaction with any known cardiovascular drug.

"We are advancing the clinical development of Topiglan consistent with our global plan by expanding this trial into the U.S., the world's largest ED market," DeLuccia said. "Expanding the scope of this trial enables U.S. investigators who had successful experience with our first-generation gel to evaluate our new cream formulation."

This Phase 2 study builds on the successful Phase 1 data with the new cream formulation, which appeared to be better tolerated than the first generation gel. It also builds on the previously completed home trial of the gel, in which a 435-patient protocol-conforming subset of 550 men with moderate-to-severe ED achieved statistically significant improvement in both primary end points: Improvement in IIEF erectile function score and improvement in intercourse completion.

As in the current U.K. trial, the new U.S. sites will utilize the same RigiScan monitoring technique to compare the response of men with erectile dysfunction to Topiglan or a placebo cream. This RigiScan technology has been used by developers of oral ED drugs to predict the likely efficacy of their products.