ABS' MH-1 BLOOD CLOT IMAGING AGENT WILL ENTER PHASE I STUDY
This article was originally published in The Gray Sheet
Executive Summary
ABS' MH-1 BLOOD CLOT IMAGING AGENT WILL ENTER PHASE I STUDY in early-to-mid April, the firm reports. FDA granted clearance of American Biogenetic Sciences' investigational new drug application on March 11. The Phase I study will evaluate the agent in 50-60 patients for detection of pulmonary embolism, intracardiac thrombosis and deep-vein thrombosis. The studies will take place at The Johns Hopkins University School of Medicine, Baltimore, Maryland, and at the West Haven Veterans' Administration Medical Center in West Haven, Connecticut. MH-1 is a monoclonal antibody "specific to the fibrin component of a blood clot" that has been labeled with technetium- 99m, a gamma-emitting radionucleotide. When used for imaging, a small amount of MH-1 is injected through the arm into the bloodstream. The firm says that, in animal studies, gamma camera- generated images of vasculature contours have indicated pulmonary embolisms and intracardiac thromboses within 15 to 30 minutes following an MH-1 injection. MH-1 is ABS' first product to enter human clinicals and its second fibrinogen-related product. The firm currently has marketing clearance for its in vitro Cadkit monoclonal antibody- based test for measuring blood fibrinogen levels ("The Gray Sheet" May 13, 1991, In Brief) and is looking for U.S. and international marketing partners for the test. Yamanouchi Pharmaceutical Co., Ltd. holds licensing rights for Japan and Taiwan. ABS says that imaging using MH-1 "will reduce the need for invasive diagnostic procedures such as pulmonary angiography." Pulmonary angiography, the "gold standard" for diagnosing pulmonary embolism, is less specific and more complicated to administer than MH-1, says the firm. Whereas imaging using MH-1 indicates the presence and location of an embolism, pulmonary angiography only shows the location of unspecified obstructions. Pulmonary angiography permits imaging of the vessels after a contrasting agent is introduced into the bloodstream through a catheter and can take from several minutes to several hours to perform. Risks associated with the procedure include blood vessel damage due to the catheter and allergic reactions to the imaging agent. ABS notes that approximately 500,000 cases of pulmonary embolism occur each year in the U.S. and that this condition is "the leading cause of preventable deaths in hospitals today." ABS says that no specific tests currently are available to detect intracardiac thromboses. MH-1, which the firm believes should fill this diagnostic gap, should also improve upon contrast venography, the established test for detecting deep-vein thrombosis. Contrast venography is not only time-consuming and "uncomfortable" for the patient, but the dye used in the procedure has been shown to cause clots, says the firm. ABS also believes that its in vivo and in vitro diagnostics may be useful for other indications such as the early diagnosis and treatment of Alzheimer's disease.