Lisa Seachrist

Washington Editor

Less than 90 days after receiving a non-approvable letter from the FDA for its lead compound, Matrix Pharmaceuticals Inc. amended its new drug application (NDA) and got the review back on track.

The amendment to the NDA for AccuSite Injectable Gel as a treatment for genital warts puts the ball back into the agency's court, but Matrix is planning a mid-1998 launch.

"We are definitely pleased that we were able to address the agency's concerns," said Peter Dworkin, senior director of investor relations and corporate communications for the Fremont, Calif., company. "We look forward to the completion of the review process. We do expect that AccuSite can be approved by the end of the year."

AccuSite is directly injected into genital warts, where it provides a sustained release of a standard chemotherapeutic agent, fluorouracil (5-FU). The company has tested the product in more than 2,000 patients. Phase III trial results for AccuSite were published in the January 1997 issue of the Archives of Dermatology.

On December 23, 1996, Matrix received an action letter from the agency which raised concerns about the chemistry of AccuSite Injectable Gel, as well as concerns about its potential side effects, including swelling at the injection site.

At that time, the company requested a meeting with the FDA to clarify the agency's concerns. After that meeting in mid-February, Dworkin said the company reanalyzed the data and "that analysis convinced us that we could adequately address their concerns."

"As a result, we were able to file the amendment without conducting additional clinical or preclinical studies," Dworkin said, noting that when analysts first heard that the company received a non-approvable letter, they assumed Matrix would need more clinical data.

"We are confident that we have answered the agency's concerns," Dworkin said. "And we were very encouraged by the productive and positive dialogue that characterized the tenor of our meeting."

When Matrix released the news of AccuSite's setback, the company's stock plummeted by 30 percent. Their stock (NASDAQ:MATX) closed Thursday at $6.12, up $0.12.

AccuSite gained approval in the United Kingdom in January. Matrix has applied for market clearance in France, Germany, Italy and Sweden. The company also has applied for approval in eight other member states through the European Union's mutual recognition process. Dworkin said AccuSite will be considered at the May meeting of the EU's Committee for Proprietary Medicinal Products, which will make a recommendation for or against approval by the end of May.

Dworkin noted the company would be able to take AccuSite to market in the United States within 90 days of FDA approval.

In addition to AccuSite, Matrix has IntraDose — a biodegradable gel formulation of cisplatin — in Phase III trials for the treatment of refractory head and neck cancers. Like AccuSite, IntraDose allows for a sustained release of the drug directly into tumors. Dworkin said a 1998 NDA filing was likely for IntraDose. *