Versicor Inc., just a month after agreeing to acquire collaborator Biosearch Italia SpA, reported positive results from a Phase II trial of its antibiotic, dalbavancin, for the treatment of skin and soft-tissue infections.

Dalbavancin, a glycopeptide agent that belongs to the same class as vancomycin, is being developed as the first once-weekly injectable antibiotic for Staphylococcal aureus and other Gram-positive hospital infections, the company said.

The trial demonstrated that dalbavancin administered once a week for two weeks had "higher clinical and microbiological response rates than a variety of standard-care regimens, including vancomycin," when given for a mean duration of 15 days, the company said.

"It is a very important milestone for the company," Dov Goldstein, Versicor's vice president of finance and chief financial officer, told BioWorld Today. "It also lays the groundwork for the dosing of the Phase III study, which will begin in the fourth quarter in complicated skin and soft-tissue [infections]."

The trial involved 62 hospitalized patients with SSTIs involving deep skin structures or requiring surgical intervention, such as abscesses, infected ulcers, burns and cellulitis, the company said.

The primary endpoint of Fremont, Calif.-based Versicor's trial was clinical response at follow-up. The outcome in that group demonstrated a 94.1 clinical success rate with two doses of dalbavancin given one week apart, compared with 76.2 percent for the standard-care arm and 61.5 percent for the single-dose dalbavancin arm, the company said.

Microbiological success was 72.7 percent with two weekly doses, compared with 64.3 percent for standard of care and 27.3 percent for the single-dose dalbavancin arm.

"We're extremely excited about this drug," Goldstein said, noting that one of the main sources of bloodstream infections is via catheters, and that dalbavancin dosing once a week "may offer the possibility of taking catheters out early, which would reduce the risk of bloodstream infection as well as local infection."

Dalbavancin is also in Phase II trials for bloodstream infections that are catheter-related.

Versicor's lead product, anidulafungin, is in Phase III trials for esophageal candidiasis and aspergillus, and in a Phase II study in invasive candidiasis. Goldstein said the Phase III data are expected in March, and if the results are positive, the company would file a new drug application with the FDA in April of next year.

In July, Versicor reported that it had agreed to buy Biosearch Italia for $260.7 million in a stock swap expected to close early next year. Antibiotics and antifungals will be the focus of the new company. (See BioWorld Today, Aug. 1, 2002.)

Biosearch Italia, of Milan, Italy, has oral ramoplanin in Phase III trials for bloodstream infections caused by vancomycin-resistant enterococci, which is being developed with licensing partner Genome Therapeutics Corp., of Waltham, Mass. (See BioWorld Today, Oct. 10, 2001.)

Versicor's stock (NASDAQ:VERS) gained 14 cents Thursday to close at $10.52.