Three months after receiving an approvable letter from the FDA, Vicuron Pharmaceuticals Inc. finalized plans to address its new drug application for anidulafungin.

The King of Prussia, Pa.-based company said it plans to pursue two routes to approval for the antifungal agent, based on discussions with the agency and the approvable letter. Vicuron will keep its initial NDA open and file an amendment for the broad-spectrum product's use in treating esophageal candidiasis, the indication for which it first filed for approval, and in about a year will file another NDA for invasive candidiasis/candidemia.

"There were some question marks around exactly what the regulatory strategy for anidulafungin would be," Dov Goldstein, Vicuron's chief financial officer, told BioWorld Today. "Now we have that cleared up with two pathways."

The company does not have to conduct additional studies, though it must complete an ongoing trial in order to augment its existing NDA. To that end, Vicuron expects the amendment to provide supplemental clinical data for anidulafungin largely at the 100-mg dose, in part from a pivotal Phase III study that has completed its enrollment of 250 invasive candidiasis patients. (A previous large trial for esophageal candidiasis tested a 50-mg dose.)

"Management indicated that the safety and efficacy data for anidulafungin from the invasive candidiasis study may (along with other data) be suitable to overcome the agency's concerns on the approvability of the drug for the treatment of esophageal candidiasis," Gregory Wade, an analyst with Pacific Growth Equities in San Francisco, wrote in a research note. He upgraded Vicuron's securities based on the improved visibility into potential regulatory paths.

Vicuron expects to file the amendment in the second quarter of next year, meaning that the earliest anidulafungin could be approved for esophageal candidiasis would be the fourth quarter of 2005.

"We, as a company, would really like to focus on not interpreting what [the FDA] needs, but rather on what we're committed to delivering," Goldstein said. "We discussed and went back and forth with the FDA on the efficacy and safety information we will provide for both files."

For the treatment of invasive candidiasis/candidemia, the company will file a new NDA using clinical data to provide a statistical analysis of all studies with the product. It will include findings from the recently completed pivotal trial, which are expected to be released in the first half of next year. Vicuron plans to submit the second NDA in the third quarter of next year and expects a standard 10-month review period for the filing.

"These are two parallel paths," Goldstein said. "You can have two NDAs open at the same time, but you can't do a supplemental NDA for another indication until you get an approved NDA, and we won't yet have an approved NDA when we file the second one."

The original NDA was filed about a year and a half ago, and the approvable letter was released a little more than a year later, indicating concerns about a secondary endpoint associated with relapse rate after two weeks of follow-up. That news caused the company's stock to lose about 40 percent of its value. (See BioWorld Today, April 29, 2003, and May 25, 2004.)

Vicuron gained rights to anidulafungin about five years ago though an in-licensing deal from Eli Lilly and Co., of Indianapolis.

Outside of anidulafungin, Vicuron's portfolio includes another product about to go through the FDA's regulatory proceedings. Last month the company unveiled plans to file by the end of this year for approval of dalbavancin, an injectable, hospital-based antibiotic that can be administered once weekly. Favorable Phase III data pointed to the semi-synthetic glycopeptide's ability to treat skin and soft-tissue infections caused by Gram-positive bacteria. That news caused the company's stock to jump about 20 percent. (See BioWorld Today, Aug. 13, 2004.)

Dalbavancin was discovered by Biosearch Italia SpA, the firm in Milan, Italy, which two years ago merged with Versicor Inc. in a $225 million transaction to form Vicuron. It owns all rights to anidulafungin and dalbavancin. (See BioWorld Today, Aug. 1, 2002.)

On Tuesday, its shares (NASDAQ:MICU) fell 11 cents to close at $15.86.