Drug – bio-affecting and body treating compositions – Radionuclide or intended radionuclide containing; adjuvant... – In an organic compound
Patent
1995-01-05
1999-07-20
Hollinden, Gary E.
Drug, bio-affecting and body treating compositions
Radionuclide or intended radionuclide containing; adjuvant...
In an organic compound
534 14, 530380, 530382, 530331, A61K 5108, A61K 3514, C07F 1300
Patent
active
059253312
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to radiodiagnostic reagents and methods for producing labeled radiodiagnostic agents. Specifically, the invention relates to reagents that can be labeled with technetium-99m (Tc-99m), methods and kits for making and radiolabeling such reagents, and methods for using such reagents to image sites of thrombus formation in a mammalian body.
2. Description of the Related Art
Thrombosis and thromboembolism, in particular deep vein thrombosis DVT) and pulmonary embolism (PE), are common clinical conditions that are associated with significant morbidity and mortality. It has been estimated that in the U.S. approximately 5 million patients experience one or more episodes of DVT per year and that over 500,000 cases of PE occur, resulting in 100,000 deaths (J. Seabold, Society of Nuclear Medicine Annual Meeting 1990). It has also been estimated that over 90% of all pulmonary emboli arise from DVT in the lower extremities. Foretunately, anticoagulant therapy can effectively treat these conditions, if applied early enough. However, such treatment is associated with risks (e.g. internal bleeding) that preclude unnecessary prophylactic application. More advanced techniques of thrombolytic intervention (such as the administration of recombinant tissue plasminogen activator or streptokinase) can be used in acute cases, but these techniques carry even greater risks. Moreover, effective clinical application of these techniques requires that the site of the offending thrombus be identified so as to monitor the effectiveness of treatment.
For these reasons, a rapid means of localizing thrombi in vivo, most preferably using non-invasive methods, is highly desirable. Methods currently utilized for the identification of thrombolytic sites are contrast venography and compression B-mode ultrasound; the choice of which technique is used depends on the expected location of the thrombus. However the former technique is invasive, and both techniques are uncomfortable for the patient. In addition, these methods are in many cases either unsuitable or yield inaccurate results.
In the field of nuclear medicine, certain pathological conditions are localized, or their extent is assessed, by detecting the distribution of small quantities of internally-administered, radioactively-labeled tracer compounds (called radiotracers or radiopharmaceuticals). Methods for detecting these radiopharmaceuticals are known generally as imaging or radioimaging methods.
In radioimaging, the radiolabel is a gamma-radiation emitting radionuclide and the radiotracer is located using a gamma-radiation detecting camera (this process is often referred to as gamma scintigraphy). The imaged site is detectable because the radiotracer is chosen either to localize at a pathological site (termed positive contrast) or, alternatively, the radiotracer is chosen specifically not to localize at such pathological sites (termed negative contrast).
A number of factors must be considered for optimal radioimaging in humans. To maximize the efficiency of detection, a radionuclide that emits gamma energy in the 100 to 200 keV range is preferred. To minimize the absorbed radiation dose to the patient, the physical half-life of the radionuclide should be as short as the imaging procedure will allow. To allow for examinations to be performed on any day and at any time of the day, it is advantageous to have a source of the radionuclide always available at the clinical site.
A variety of radionuclides are known to be useful for radioimaging, including .sup.67 Ga, .sup.99m Tc (Tc-99m), .sup.111 In, .sup.123 I, .sup.125 I, .sup.169 Yb or .sup.186 Re. Tc-99m is a particularly preferred radionuclide because it emits gamma radiation at 140 keV, it has a physical half-life of 6 hours, and it is readily available on-site using a molybdenum-99/technetium-99m generator.
Radioimaging, specifically gamma scintigraphy, provides a non-invasive method for detecting the location of thrombi in vivo. A gamma-emitting radiotracer
REFERENCES:
patent: 4578079 (1986-03-01), Ruoslahti et al.
patent: 4792525 (1988-12-01), Ruoslahti et al.
patent: 4957903 (1990-09-01), Ranby
patent: 5371184 (1994-12-01), Rajagopalan et al.
patent: 5443816 (1995-08-01), Zamora et al.
* Knight, 1990, "Radiopharmceuticals for Thrombus Detection", Sem. Nucl. Med. 20:52-67.
Baidoo & Lever, 1990, "Synthesis of a Diaminedithiol Bifunctional Chelating Agent for Incorporation of Technetium-99m into Biomolecules", Bioconjugate Chem. 1: 132-137.
Bryson et al., 1990, "Protecting Groups in the Preparation of Thiolate Complexes of Technetium", Inorganic Chem. 29: 2948-2951.
Dean Richard T.
Lister-James John
Diatide, Inc.
Hartley Michael G.
Hollinden Gary E.
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