Method of diagnosing blood clots using fibrin-binding proteins

• US 5,217,705 A
• Filed: 09/22/1988
• Issued: 06/08/1993
• Est. Priority Date: 09/25/1987
• Status: Expired due to Fees

• Current Assignee: NeoRx Corporation, Genentech, Inc. (Roche Holding AG)
• Original Assignee: NeoRx Corporation
• Inventors: Mohler, Marjorie A., Reno, John M., Hadley, Stephen W.
• Primary Examiner(s): Stoll, Robert L.
• Assistant Examiner(s): COVERT, JOHN
• Application Number:
  US07/247,973
• Time in Patent Office: 1,720 Days
• Field of Search: 424/1.1, 530/380, 530/402, 530/409, 530/410, 930/280
• US Class Current: 424/1.69
• CPC Class Codes: A61K 2121/00 Preparations for use in therapy
• CPC Class Codes: A61K 2123/00 Preparations for testing in vivo
• CPC Class Codes: A61K 51/08 Peptides, e.g. proteins , carriers being peptides, polyamino acids, proteins
• CPC Class Codes: A61K 51/088 conjugates with carriers being peptides, polyamino acids or proteins antibodies A61K51/10
• CPC Class Codes: Y10S 930/28 Bound to a nonpeptide drug, nonpeptide label, nonpeptide carrier, or a nonpeptide resin

Abstract

A fibrin-binding protein such as t-PA is labeled with a detectable substance, such as a radionuclide, and administered to a patient for diagnosis of blood clots and for monitoring the dissolution thereof during therapy. The detectable substance preferably is attached to t-PA through linkers which specifically bind to the portion of the t-PA protein responsible for enzymatic activity, thereby diminishing this activity while leaving the fibrin-binding property of the protein intact.

Claims

1. A method for detecting a fibrin-platelet clot in vivo, comprising the steps of:

(a) intravenously administering to a patient suspected of having a fibrin-platelet clot a radiolabeled thrombolytic protein wherein the radiolabeled thrombolytic protein'"'"'s clot-dissolving activity is eliminated or reduced to a degree sufficient to prolong localization of the protein at a fibrin-platelet clot, compared to localization of a corresponding native protein at a fibrin-platelet clot, and the radiolabel is selectively attached through a linker that binds specifically to a portion of the thrombolytic protein other than a fibrin-binding domain; and

p1 (b) detecting the biodistribution of the radiolabeled thrombolytic protein in the patient.

2. The method of claim 1 wherein said radiolabeled thrombolytic protein is t-PA.

3. The method of claim 1 or 2 wherein said radiolabel is a radionuclide metal bound within a chelate.

4. The method of claim 3 wherein said radionuclide metal is ^99m Tc and detecting the biodistribution of the ^99m Tc is by scanning the patient with a gamma camera.

5. The method of claim 1 wherein said radiolabeled substance is attached to the thrombolytic protein through a linker which specifically binds to a clot-dissolving portion of the thrombolytic protein.

6. The method of claim 5 wherein said thrombolytic protein is a fibrin-binding serine protease and the linker is an oligopeptide chloromethyl ketone that binds to the clot-dissolving portion of the serine protease.

7. The method of claim 6 wherein said thrombolytic protein is t-PA and said linker is selected from D-Phe-L-Pro-L-Arg-CH₂ Cl or Tyr-L-Pro-L-Arg-CH₂ Cl.

8. The method of claim 5, 6, or 7 wherein said radiolabel is a radionuclide metal bound within a chelate.

9. The method of claim 1 wherein said clot-dissolving activity is essentially eliminated.

10. A thrombolytic protein having a radioisotope attached thereto, wherein the radioisotope is attached to said thrombolytic protein through a linker that binds specifically to a portion of the protein other than a fibrin-binding domain.

11. The thrombolytic protein of claim 10, wherein the thrombolytic protein is t-PA and the linker is derived from an oligopeptide chloromethyl ketone inhibitor of t-PA.