Immunosuppression compound and treatment method

• US 20070111962A1
• Filed: 11/08/2006
• Published: 05/17/2007
• Est. Priority Date: 11/08/2005
• Status: Abandoned Application

• Current Assignee: Avi Biopharma, Inc.
• Original Assignee: Avi Biopharma, Inc.
• Inventors: Weller, Dwight, Mourich, Dan, Iversen, Patrick
• Application Number:
  US11/595,161
• Publication Number:
  US 20070111962A1
• Time in Patent Office: Days
• US Class Current: 514/44.A
• CPC Class Codes: C12N 15/1138 against receptors or cell surface proteins
• CPC Class Codes: C12N 2310/11 Antisense
• CPC Class Codes: C12N 2310/3233 Morpholino-type ring
• CPC Class Codes: C12N 2310/3513 Protein; Peptide

Abstract

A method and compound for suppressing an immune response in a mammalian subject, for the treatment or prevention of an autoimmune condition or transplantation rejection are disclosed. The compound is an antisense oligonucleotide analog compound having a targeting sequence complementary to a preprocessed CTLA-4 mRNA region identified by SEQ ID NO: 1, spanning the splice junction between intron 1 and exon 2 of the preprocessed mRNA of the subject. The compound is effective, when administered to a subject, to form within host cells, a heteroduplex structure (i) composed of the preprocessed CTLA-4 mRNA and the oligonucleotide compound, (ii) characterized by a Tm of dissociation of at least 45° C., and (iii) resulting in an increased ratio of processed mRNA encoding ligand-independent CTLA-4 to processed mRNA encoding full-length CTLA-4.

Claims

1. A method of suppressing an immune response in a mammalian subject, for the treatment or prevention of an autoimmune condition or transplantation rejection, comprising

(a) administering to the subject, a pharmaceutically effective amount of an oligonucleotide analog compound characterized by:

(i) a nuclease-resistant backbone,

(ii) capable of uptake by mammalian host cells,

(iii) containing between 12-40 nucleotide bases, and

(iv) having a targeting sequence of at least 12 subunits that is complementary to at least 12 subunits of a target sequence identified by SEQ ID NO;

1, spanning the splice junction between intron 1 and exon 2 of preprocessed T cell antigen-4 (CTLA-4) mRNA of the subject, and

(b) by said administering, forming within said cells a heteroduplex structure (i) composed of the preprocessed CTLA-4 mRNA and the oligonucleotide compound, (ii) characterized by a Tm of dissociation of at least 45°

C., and (iii) resulting in an increased ratio of processed mRNA encoding ligand-independent CTLA-4 to processed mRNA encoding full-length CTLA-4.

2. The method of claim 1, wherein the compound to which the subject is exposed is composed of morpholino subunits linked phosphorus-containing intersubunit linkages, joining a morpholino nitrogen of one subunit to a 5′

exocyclic carbon of an adjacent subunit.

3. The method of claim 2, wherein said intersubunit linkages are phosphorodiamidate linkages.

4. The method of claim 3, wherein said morpholino subunits are joined by phosphorodiamidate linkages, in accordance with the structure:

5. The method of claim 2, in which at least 2 and no more than half of the total number of intersubunit linkages are positively charged at physiological pH.

6. The method of claim 2, wherein said morpholino subunits are joined by phosphorodiamidate linkages, in accordance with the structure:

7. The method of claim 4, wherein X=NR₂, where each R is independently hydrogen or methyl.

8. The method of claim 2, which the compound to which the subject is exposed is a conjugate of the compound and an arginine-rich polypeptide effective to promote uptake of the compound into target cells.

9. The method of claim 8, wherein the arginine rich peptide has one of the sequences identified as SEQ ID NOS:

15-20.

10. The method of claim 8, wherein the arginine-rich peptide is covalently coupled at its C terminus to the 5′

end of the compound.

11. The method of claim 1, wherein said targeting sequence is complementary to at least 12 subunits of a target sequence identified by SEQ ID NO:

2 within the 5′

-end region of exon 2 of preprocessed T cell antigen-4 (CTLA-4) mRNA of the subject.

12. The method of claim 11, wherein the compound sequence includes the sequence defined by SEQ ID NO:

4.

13. The method of claim 1, wherein said targeting sequence is complementary to at least 12 subunits of a target sequence identified by SEQ ID NO:

3 containing the branch point site and/or splice acceptor site of intron 1 of preprocessed T cell antigen-4 (CTLA-4) mRNA of the subject.

14. The method of claim 13, wherein the compound sequence includes one of the sequences defined by SEQ ID NOS:

6 and 7.

15. The method of claim 1, for prevention of transplantation rejection in a human subject scheduled to receive an allogeneic organ transplantation, wherein said administering is initiated at least one week before the scheduled transplantation.

16. The method of claim 15, wherein said administering is carried out by parenteral administration, at a dose level corresponding to between about 5 to 200 mg compound/day.

17. The method of claim 1, for treatment of an autoimmune condition, wherein said exposing is continued until a desired improvement in autoimmune condition is observed.

18. The method of claim 17, wherein said administering is carried out by parenteral administration, at a dose level corresponding to between about 5 to 200 mg compound/day.

19. An oligonucleotide analog compound for use in suppressing an immune response in a mammalian subject, for the treatment or prevention of an autoimmune condition or transplantation rejection, characterized by:

(i) a nuclease-resistant backbone,

(ii) capable of uptake by mammalian host cells,

(iii) containing between 12-40 nucleotide bases, and

(iv) having a targeting sequence of at least 12 subunits that is complementary to at least 12 subunits of a target sequence identified by SEQ ID NO;

1, spanning the splice junction between intron 1 and exon 2 of preprocessed cytotoxic T cell antigen-4 (CTLA-4) mRNA of the subject, and

(b) capable of reacting with the preprocessed CTLA-4 mRNA in mammalian cells to form a heteroduplex complex (i) characterized by a Tm of dissociation of at least 45°

C., and (ii) resulting in an increased ratio of processed mRNA encoding ligand-independent CTLA-4 to processed mRNA encoding full-length CTLA-4.

(i) characterized by a Tm of dissociation of at least 45°

C., and (ii) effective to increase the ratio of processed mRNA encoding ligand-independent CTLA-4 to processed mRNA encoding full-length CTLA-4 in the cells.

20. The compound of claim 19, which is composed of morpholino subunits linked by phosphorus-containing intersubunit linkages, joining a morpholino nitrogen of one subunit to a 5′

exocyclic carbon of an adjacent subunit.

21. The compound of claim 20, wherein said intersubunit linkages are phosphorodiamidate linkages.

22. The compound of claim 21, wherein said morpholino subunits are joined by phosphorodiamidate linkages, in accordance with the structure:

23. The compound of claim 20, in which at least 2 and no more than half of the total number of intersubunit linkages are positively charged at physiological pH.

24. The compound of claim 23, wherein said morpholino subunits are joined by phosphorodiamidate linkages, in accordance with the structure:

25. The compound of claim 22, wherein X=NR₂, where each R is independently hydrogen or methyl.

26. The compound of claim 19, which is a conjugate of the compound and an arginine-rich polypeptide effective to promote uptake of the compound into target cells.

27. The compound of claim 25, wherein the arginine rich peptide has one of the sequences identified as SEQ ID NOS:

10-15.

28. The compound of claim 27, wherein arginine-rich peptide is covalently coupled at its C terminus to the 3′

end of the compound.

29. The compound of claim 19, whose targeting sequence is complementary to at least 12 subunits of a target sequence identified by SEQ ID NO:

2 within the 5′

-end region of exon 2 of preprocessed T cell antigen-4 (CTLA-4) mRNA of the subject.

30. The compound of claim 29, wherein the compound sequence includes the sequence defined by SEQ ID NO:

4.

31. The compound of claim 19, whose targeting sequence is complementary to at least 12 subunits of a target sequence identified by SEQ ID NO:

3 containing the branch site and splice acceptor site of intron 1 of preprocessed T cell antigen-4 (CTLA-4) mRNA of the subject.

32. The compound of claim 31, wherein the compound sequence includes one of the sequences defined by SEQ ID NOS:

6 and 7.