By Lisa Seachrist

Washington Editor

WASHINGTON — Diatide Inc. received marketing approval for its lead product, AcuTect, a peptide-based imaging agent that detects acute venous thrombosis.

The product, which garnered priority review in August 1997, was cleared for marketing Tuesday and should be available to radiological imaging labs by Sept. 28. It is the first of the company's products to win marketing approval, and triggers a $2 million milestone payment from development partner Nycomed Amersham plc, of London.

Daniel Harrington, chief financial officer for Londonderry, N.H.-based Diatide, said the FDA "worked very hard on their end. This was as pleasant as a regulatory process can be."

AcuTect will be co-marketed with Nycomed in the U.S., where it will cost $350 per treatment. Nycomed will market the product in Europe, South Africa and the Middle East and has already filed for regulatory approval in the European Union.

AcuTect is synthetic peptide conjugated with technetium-99m, a radioactive molecule that emits gamma radiation. The peptide binds to glycoprotein IIb/IIIa, which is only present when platelets are activated. As a result, the diagnostic targets newly developed blood clots.

Other diagnostic modalities currently used, such as ultrasound or contrast venography (a dye procedure), look at structural changes in the blood flow through the veins in the leg. These procedures do not reveal the type of clot they detect.

Newly active clots require aggressive treatment with anticoagulants and often hospitalization to prevent the clots from traveling to the lung, causing a pulmonary embolism. Older clots, or chronic deep vein thrombosis, can be treated with anti-inflammatory agents and leg elevation.

AcuTect's peptide component adheres specifically to the unique receptors on the surface of activated platelets, which make up an integral part of an acute thrombosis. As a thrombus ages and becomes chronic, it stabilizes, and the activated platelets break down. At this stage, AcuTect will no longer image it.

AcuTect is indicated in patients with the signs and symptoms of acute deep vein thrombosis — pain and swelling of the lower extremities. These blood clots can result from trauma, surgery or stasis due to inactivity. Patients receive an intravenous injection of AcuTect. The drug is allowed to circulate and bind to any active clots for up to two hours. Patients are then scanned with a gamma radiation detector to identify active clots and determine appropriate treatment.

Analysts Peg Market At Between $50M And $100M

Harrington noted that, while ultrasound does a good job identifying clots in legs, up to 28 percent of all ultrasound tests produce equivocal results. He told BioWorld Today AcuTect could claim that market as well as the contrast venography market. Analysts estimate the entire market to be worth between $50 million and $100 million per year.

In addition to AcuTect, Diatide has filed a new drug application with the FDA for NeoTect, its imaging agent to detect malignant lung tumors. That product received priority review status in June.

"We're two for two at this point, which will be a tough act to follow," Harrington said.

Diatide's stock, (NASDAQ:DITI) closed Tuesday at $8.687 up $0.562. *