In a safety and efficacy study of its PT-141 drug for erectile dysfunction, Palatin Technology reported statistically significant improvement in erections across all four dosing levels tested, with no cardiovascular side effects, the tiny Cranbury, New Jersey-based company said.

Results of the month-long study, which involved 271 patients with mild to severe erectile dysfunction who had previously responded well to sildenafil citrate (Viagra), were presented Saturday night at a medical conference in Los Angeles.

"The clinical results here indicate that there is no reason why we can't move this drug forward and get it approved," Palatin Chief Executive Carl Spana told Reuters.

The trial gave patients either a placebo or the Palatin drug at 5-milligram, 10-mg, 15-mg or 20-mg doses.

The one piece of apparently negative news to come out of the study was that some 12% of patients discontinued use of the drug due to adverse side effects.

About 60% of the discontinuations were due to gastrointestinal problems, and those were limited to patients taking the two higher doses, the company said. Virtually none of the dropouts were taking the two lower doses.

Palatin said in next trial it will eliminate the 20-mg dose.

Even with no unforeseen hitches in what Spana called "a very clear path to approval," it will be late 2007 or early 2008 before Viagra and its similar competitors face a challenge from this new class of drug, the company predicted.

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