By Frances Bishopp

Diatide Inc. has submitted its first new drug application for its lead product, P280, known as AcuTect, for the detection and localization of acute venous thrombosis.

The product is the first of Diatide's pipeline to be submitted for marketing approval, Ron Kinder, executive vice president and chief operating officer at the Londonderry, N.H.-based company, told BioWorld Today.

AcuTect is a receptor imaging agent that is highly specific for detecting glycoprotein IIb/IIIa, which is only available when platelets become activated, Kinder explained.

Other diagnostic modalities currently used, such as ultrasound or contrast venography (dye procedure), look at structural changes. "Ultrasound measures the flow of blood through the veins in the leg. If a lower flow is found, there is the assumption a clot may be there," Kinder said. Ultrasound, however, doesn't reveal what kind of clot it detects. At present, there are no procedures on the market which reliably detect the activity of an acute clot.

The significant difference between AcuTect and ultrasound, as was demonstrated in a Phase III trial, Kinder pointed out, is that AcuTect can differentiate new clots from old clots.

New clots require aggressive therapy, possibly hospitalization and treatment with anticoagulants. Old clots, or chronic deep vein thrombosis, can be treated with anti-inflammatory agents and leg elevation.

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

Analyst Mary Ann Gray, of Dillon, Read & Co. Inc., of New York, said the initial market for AcuTect is several hundred thousand patients, which could result in substantial revenues for Diatide.

"Diatide's novel peptide-based imaging technology overcomes many of the disadvantages of monoclonal antibody-based products. We feel that Diatide has a strong proprietary position in this area as well as a lead in the development of these agents," Gray said.

Another product in Diatide's pipeline is techtide P829, which is currently in three Phase III trials: for the detection and localization of lung cancer, for the detection of malignant melanoma and for the detection of neuroendocrine tumors.

Another product, P483H, is in Phase II trials for the detection of sites of infection and P748 is in Phase II trials for the detection of pulmonary emboli. A third product, Sn-117m (not a peptide), is in Phase II/III clinical trials for relief of bone pain associated with metastatic cancer.

AcuTect is licensed to Nycomed A.S.A., of Oslo, Norway, for regulatory approval and distribution in Europe, South Africa and parts of the Middle East. In the U.S., Nycomed and Diatide have an agreement to market the product on a joint basis. Nycomed plans to file for European regulatory approval of AcuTect in the fourth quarter of 1997. *