Atomic description of immune complex that causes heparin-induced thrombocytopenia

Patent metadata

Field	Value
Publication number	US-2018024140-A1
Application number	US-201515524511-A
Country	US
Kind code	A1
Filing date	Nov 5, 2015
Priority date	Nov 6, 2014
Publication date	Jan 25, 2018
Grant date	—

Abstract

The present invention provides a humanized antibody or antibody fragment comprising (a) a humanized light chain comprising 1) Complementarity Determining Region (CDR)-L1, the sequence of which is identical to the sequence of SEQ ID NO: 3; 2) CDR-L2, the sequence of which is identical to the sequence of SEQ ID NO: 4; and 3) CDR-L3, the sequence of which is identical to the sequence of SEQ ID NO: 5, and (b) a humanized heavy chain comprising 1) CDR-H1, the sequence of which is identical to the sequence of SEQ ID NO: 6; 2) CDR-H2, the sequence of which is identical to the sequence of SEQ ID NO: 7; and 3) CDR-H3, the sequence of which is identical to the sequence of SEQ ID NO: 8, as well as methods for treating, diagnosing, and monitoring the progression of HIT. The present invention also provides methods for assessing the antigenicity and ability to cause HIT of anionic anticoagulants. The present invention also provides a mutant protein which has the same amino acid sequence of a wild type PF4 monomer except that (i) at least one amino acid of the wild type PF4 monomer has been deleted, (ii) at least one amino acid of the wild type PF4 monomer has been replaced by another amino acid, or (iii) a combination of such changes has been made. The present invention also provides methods of treating or reducing the likelihood of HIT, treating angiogenesis, treating abnormal cell growth, or affecting coagulation pathologies that lead to thrombus formation, by administering such mutant proteins to a patient.

First claim

1 - 15 . (canceled)

16 . A method for detecting heparin-induced thrombocytopenia (HIT) in a subject, comprising
i) obtaining a plasma or serum sample from the subject; and ii) detecting whether HIT is present by determining the ratio of
(1) the reactivity of antibodies in the sample to wild-type PF4, to
(2) the reactivity of antibodies in the sample to a mutant PF4 monomer that remains in a monomeric state.

17 . The method of claim 16 , wherein the subject is diagnosed as having HIT if the ratio of (1) to (2) in the sample is equal to or greater than a reference ratio of (1) to (2) obtained from a plasma or serum sample from a subject or group of subjects afflicted with HIT.

18 - 20 . (canceled)

21 . The method of claim 16 , wherein determining the ratio of (1) and (2) comprises ELISA.

22 . The method of claim 21 , wherein the ratio of (1) to (2) is obtained using the optical density for (1) and the optical density for (2) obtained using ELISA.

23 - 25 . (canceled)

26 . The method of claim 16 , wherein heparin is being or has been administered to the subject.

27 . The method of claim 26 , wherein the heparin is low-molecular-weight heparin or unfractionated heparin.

28 . The method of claim 16 , wherein a heparin mimic is being or has been administered to the subject.

29 . The method of claim 28 , wherein the heparin mimic is fondaparinux.

30 - 39 . (canceled)

40 . A mutant platelet factor 4 (PF4) monomer which has the same amino acid sequence of wild type PF4 monomer except that
(i) at least one amino acid of the wild type PF4 monomer has been deleted, (ii) at least one amino acid of the wild type PF4 monomer has been replaced by another amino acid, or (iii) a combination of such changes has been made.

41 . The mutant platelet factor 4 (PF4) monomer of claim 40 , wherein the at least one amino acid that has been deleted or replaced is on the N-terminal end of the wild type PF4 monomer.

42 . The mutant platelet factor 4 (PF4) monomer of claim 40 , wherein at least 8 amino acids are deleted from the N-terminal end of a wild type PF4 monomer.

43 . The mutant platelet factor 4 (PF4) monomer of claim 42 , wherein the amino acid sequence of the mutant protein comprises SEQ ID NO:17.

44 . The mutant platelet factor 4 (PF4) monomer of claim 40 , wherein at least 5 amino acids are deleted from the N-terminal end of a wild type PF4 monomer.

45 . The mutant protein of claim 40 , wherein the mutant platelet factor 4 (PF4) monomer interferes with wild type PF4 tetramer oligomerization.

46 . A method for treating a subject afflicted with heparin-induced thrombocytopenia (HIT) or coagulation pathologies that lead to thrombus formation, angiogenesis or abnormal cell growth comprising administering to the subject an effective amount of the mutant platelet factor 4 (PF4) monomer of claim 40 so as to interfere with PF4 tetramer oligomerization.

47 - 48 . (canceled)

Assignees

• Univ Pennsylvania

Inventors

• Greene Mark I
• Cines Douglas B
• Cai Zheng
• Zhu Zhiqlang

Classifications

• G01N2800/52

  Predicting or monitoring the response to treatment, e.g. for selection of therapy based on assay results in personalised medicine; Prognosis · CPC title

• G01N2800/50

  Determining the risk of developing a disease · CPC title

• C07K16/24

  against cytokines, lymphokines or interferons · CPC title

• A61K2039/505

  comprising antibodies · CPC title

• G01N33/6863 Primary

  Cytokines, i.e. immune system proteins modifying a biological response such as cell growth proliferation or differentiation, e.g. TNF, CNF, GM-CSF, lymphotoxin, MIF or their receptors · CPC title