Pfizer ( PFE) has received conditional approval from the Food and Drug Administration for a new fungal infection drug, but the company declined to say what the conditions are or how long it will take to meet those requirements. The drug, called anidulafungin, is designed to fight fungal infections that affect the skin or mucous membrane but that also can enter the bloodstream and damage the heart. Pfizer initially asked the FDA to approve the drug for fungal infections of the esophagus. The FDA was scheduled to act in late November, but the company didn't announce the agency's response. A Pfizer spokesman on Tuesday confirmed that his company received an "approvable letter" from the FDA on Nov. 25, indicating the agency wanted more information. He declined to comment on the requirements. Anidulafungin is one of two anti-infectives that were in late-stage development at Vicuron Pharmaceuticals when Pfizer offered $1.9 billion for the company on June 16. The deal closed Sept.14. The other Vicuron product, the antibiotic dalbavancin, also received conditional approval from the FDA. The agency had been scheduled to act in mid-September. Pfizer confirmed in its third-quarter financial report issued Oct. 20 that it had received conditional approval. Dalbavancin treats dangerous hospital-based infections featuring bacteria that have become resistant to other antibiotics. At the time, Pfizer declined to provide details about the requirements or a timetable, saying only that "we anticipate a rapid and successful resolution of outstanding issues." Pfizer acquired Vicuron in order to bolster its collection of infection-fighting drugs that produced $4.72 billion in sales last year, or 9% of corporate revenue. However, the antifungal Diflucan, which had $945 million in sales last year, lost U.S. patent protection in July 2004 and is being battered this year. For the first nine months of 2005, Diflucan produced $370 million in sales vs. $805 million for the same period last year. Generic competition is expected to take a greater toll on the antibiotic Zithromax, which is used primarily for respiratory infections. That drug lost U.S. patent protection last month. Last year, its worldwide sales were $1.85 billion.