By Matthew Willett

Advanced Tissue Sciences Inc. (ATS) said it has reached statistical significance in the primary endpoint of an additional clinical trial of Dermagraft for diabetic foot ulcers, its dermal fibroblast wound treatment.

ATS and partner Smith & Nephew plc, of London, submitted a premarket approval application in the U.S. based on the result.

In weekly applications up to a maximum of eight weeks, Dermagraft showed significantly improved healing over conventional treatment. For the primary endpoint, complete wound closure within 12 weeks, 30 percent of patients treated with Dermagraft healed, compared to 18 percent of control patients.

The study, designed to mimic real-world treatment, allowed its subject patients, sufferers of chronic difficult-to-heal foot ulcers, limited ambulatory freedom.

Approval would significantly increase the company's global marketing efforts for the product, which is approved in this indication in Canada, the UK, Ireland and Finland. The worldwide market for difficult-to-treat-ulcers is about 800,000 patients, 400,000 of whom are in the U.S., said ATS CEO Gail Naughton.

Clearing the product for marketing through the FDA should be a straightforward process, she added. "The data is clean," she said. "Working closely with the FDA, it should be a smooth approval."

That hasn't always been the case for ATS. Dermagraft was deemed non-approvable by the FDA in 1998, despite a 7-2 FDA advisory committee recommendation. (See BioWorld Today, June 15, 1998, p. 1.)

ATS' stock (NASDAQ:ATIS) fell 44 percent to $3.983 the day the product was deemed unapprovable in 1998. It closed Friday at $6.94, up 12.5 cents.

The need for further testing, however, turned into a blessing in disguise for the La Jolla, Calif.-based company. Further research on the tissue-growth technology revealed a host of traits that make the product a potential blockbuster, Naughton said.

"We had hardly gone back into the clinical trials when we found out more about the metabolic activity, how alive the cells were. While we were doing the additional trial we set up a collaboration to study what exactly it is about Dermagraft that makes it work," Naughton said.

What researchers found is that Dermagraft induces new blood vessel formation while reducing inflammation. The finding could be the genesis of additional indications for the product.

Dermagraft is a bioengineered, living, metabolically active skin implant derived from foreskin tissue.

"The largest market by far we've seen successful preclinical research in is from a study by the University of Arizona that shows an ability for Dermagraft to induce new blood vessel growth," Naughton said. "That allows us to develop the product to address small vessel disease and damaged heart muscles. By next year, clinical trials should add to our marketplace for Dermagraft about 59 million patients.

"I believe that the competitive advantage of Dermagraft is the fact that the product can be used with the patient still being ambulatory," she said. "The second is that the product is frozen, has a low shelf life and can be stored at the physician's office should there be a change in the patient's schedule. The product is not released until a full sterility procedure is done, and the fact that we are aligned in a joint venture with Smith & Nephew, now the world's No. 1 wound healing company, makes the product itself competitive, and gives us a practical advantage as well."

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