ENHANCING THE CIRCULATING HALF-LIFE OF ANTIBODY-BASED FUSION PROTEINS

• US 20090088561A1
• Filed: 10/02/2008
• Published: 04/02/2009
• Est. Priority Date: 02/25/1998
• Status: Abandoned Application

• Current Assignee: Merck Patent GmbH (Merck & Co., Inc.)
• Original Assignee: Merck Patent GmbH (Merck & Co., Inc.)
• Inventors: Gillies, Stephen, Wesolowski, John, Lo, Kin-Ming, Lan, Yan
• Application Number:
  US12/244,520
• Publication Number:
  US 20090088561A1
• Time in Patent Office: Days
• US Class Current: 536/23.400
• CPC Class Codes: C07K 16/30 from tumour cells
• CPC Class Codes: C07K 2317/52 Constant or Fc region; Isotype
• CPC Class Codes: C07K 2319/00 Fusion polypeptide
• CPC Class Codes: C07K 2319/30 Non-immunoglobulin-derived peptide or protein having an immunoglobulin constant or Fc region, or a fragment thereof, attached thereto

Abstract

Disclosed are methods for the genetic construction and expression of antibody-based fusion proteins with enhanced circulating half-lives. The fusion proteins of the present invention lack the ability to bind to immunoglobulin Fc receptors, either as a consequence of the antibody isotype used for fusion protein construction, or through directed mutagenesis of antibody isotypes that normally bind Fc receptors. The fusion proteins of the present invention may also contain a functional domain capable of binding an immunoglobulin protection receptor.

Claims

1. A region of a gene construct encoding an antibody-based fusion protein, the region including:

at its 5′

end, nucleotides encoding at least a portion of

1) an IgG1 CH2 domain with a mutation or a deletion at one or more amino acid residues corresponding to amino acid positions set forth in SEQ ID NO;

1 selected from the group consisting of Leu234 and Leu235, or

2) an IgG CH2 domain with a mutation or a deletion at one or more amino acid residues corresponding to an N-linked glycosylation site,

said mutation or deletion reducing binding affinity for an Fc receptor (FcR), and wherein said portion comprises a domain required for immunoglobulin protection receptor (FcRp) binding affinity, and

at its 3′

end, nucleotides encoding a non-Ig protein.

2. The region of claim 1, wherein said non-Ig protein is a cytokine.

3. The region of claim 2, wherein said cytokine is an interleukin.

4. The region of claim 1, wherein the region is fused at its 5′

end to nucleotides encoding an immunoglobulin hinge region.

5. The region of claim 1, wherein the region includes nucleotides encoding, in a 5′

to 3′

orientation, the at least a portion of an IgG CH2 domain and at least a portion of a CH3 domain.