Antibodies specific for immunoglobulin-like transcript 3 (ilt3) and uses thereof

A method for treatment of a cancer in a subject comprising:

• administering concurrently or consecutively to the subject a therapeutically effective amount of an antibody or antigen binding fragment that binds the extracellular domain of human immunoglobulin-like transcript 3 (ILT3) having amino acids 1-238 of SEQ ID NO:
• 1 and a therapeutically effective amount of one or more inhibitors or antagonists of PD-1, PD-L1, and/or PD-L2,
• wherein the antibody or antigen binding fragment that binds the extracellular domain of human ILT3 comprises:
• (a) a heavy chain complementarity determining region 1 (HC-CDR1), wherein the HC-CDR1 has the amino acid sequence set forth in SEQ ID NO:
• 17;
• an HC-CDR2, wherein the HC-CDR2 has the amino acid sequence set forth in SEQ ID NO:
• 19, 20, or 21;
• an HC-CDR3, wherein the HC-CDR3 has the amino acid sequence set forth in SEQ ID NO:
• 23;
• and
• (b) a light chain complementarity determining region 1 (LC-CDR1), wherein the LC-CDR1 has the amino acid sequence set forth in SEQ ID NO:
• 34, 35, 36, 37, 38, 39, 40, 41, or 42;
• an LC-CDR2, wherein the LC-CDR2 has the amino acid sequence set forth in SEQ ID NO:
• 43;
• and an LC-CDR3, wherein the LC-CDR3 has the amino acid sequence set forth in SEQ ID NO:
• 44.

A method for treatment of a cancer in a subject comprising administering to the subject a therapeutically effect amount of an antibody or antigen binding fragment that binds the extracellular domain of human immunoglobulin-like transcript 3 (ILT3) having amino acids 1-238 of SEQ ID NO:

• 1 and a therapeutically effective amount of one or more inhibitors or antagonists of PD-1, PD-L1, and/or PD-L2,
• wherein the antibody or antigen binding fragment that binds the extracellular domain of human ILT3 comprises:
• (a) a heavy chain complementarity determining region 1 (HC-CDR1), wherein the HC-CDR1 has the amino acid sequence set forth in SEQ ID NO:
• 17;
• an HC-CDR2, wherein the HC-CDR2 has the amino acid sequence set forth in SEQ ID NO:
• 20;
• an HC-CDR3, wherein the HC-CDR3 has the amino acid sequence set forth in SEQ ID NO:
• 23;
• and
• (b) a light chain complementarity determining region 1 (LC-CDR1), wherein the LC-CDR1 has the amino acid sequence set forth in SEQ ID NO:
• 41;
• an LC-CDR2, wherein the LC-CDR2 has the amino acid sequence set forth in SEQ ID NO:
• 43;
• and an LC-CDR3, wherein the LC-CDR3 has the amino acid sequence set forth in SEQ ID NO:
• 44.