Constructs targeting afp peptide/mhc complexes and uses thereof

Abstract

The present application provides constructs comprising an antibody moiety that specifically binds to a complex comprising an AFP peptide and an MHC class I protein. Also provided are methods of making and using these constructs.

1 : An isolated anti-AMC construct comprising an antibody moiety that specifically binds to a complex comprising an alpha-fetoprotein (AFP) peptide and a major histocompatibility (MHC) class I protein (an AFP/MHC class I complex, or AMC). 
     
     
         2 : The isolated anti-AMC construct of  claim 1 , wherein the MHC class I protein is the HLA-A*02:01 subtype of the HLA-A02 allele. 
     
     
         3 : The isolated anti-AMC construct of  claim 1 , wherein the AFP peptide has an amino acid sequence selected from the group consisting of SEQ ID NOs: 3-13 and 16. 
     
     
         4 - 5 . (canceled) 
     
     
         6 : The isolated anti-AMC construct of  claim 1 , wherein the isolated anti-AMC construct binds to the AFP/MHC class I complex with a K d  from about 0.1 pM to about 500 nM. 
     
     
         7 : The isolated anti-AMC construct of  claim 1 , wherein the antibody moiety comprises:
 i) a heavy chain variable domain comprising a heavy chain complementarity determining region (HC-CDR) 1 comprising the amino acid sequence of G-F/Y-S/T-F-D/S/T-D/N/S-Y/A-A/G/W (SEQ ID NO: 87), or a variant thereof comprising up to about 3 amino acid substitutions, an HC-CDR2 comprising the amino acid sequence of I/S-K/S-X-H/Y-X-G-X-T (SEQ ID NO: 88), or a variant thereof comprising up to about 3 amino acid substitutions, and an HC-CDR3 comprising the amino acid sequence of A/G-X-W/Y-Y-X-X-X-F/Y-D (SEQ ID NO: 89), or a variant thereof comprising up to about 3 amino acid substitutions; and   ii) a light chain variable domain comprising a light chain complementarity determining region (LC-CDR) 1 comprising the amino acid sequence of S/T-G/S-D/N-I/V-A/G-A/S/V-X-H/Y (SEQ ID NO: 120), or a variant thereof comprising up to about 3 amino acid substitutions, and an LC-CDR3 comprising the amino acid sequence of Q-S/T-Y/W-D/T-S/T-A/S (SEQ ID NO: 121), or a variant thereof comprising up to 3 amino acid substitutions, wherein X can be any amino acid.   
     
     
         8 : The isolated anti-AMC construct of  claim 1 , wherein the antibody moiety comprises:
 i) a heavy chain variable domain comprising an HC-CDR1 comprising the amino acid sequence of any one of SEQ ID NOs: 57-66, or a variant thereof comprising up to about 5 amino acid substitutions, an HC-CDR2 comprising the amino acid sequence of any one of SEQ ID NOs: 67-76, or a variant thereof comprising up to about 5 amino acid substitutions, and an HC-CDR3 comprising the amino acid sequence of any one of SEQ ID NOs: 77-86; or a variant thereof comprising up to about 5 amino acid substitutions; and   ii) a light chain variable domain comprising an LC-CDR1 comprising the amino acid sequence of any one of SEQ ID NOs: 90-99, or a variant thereof comprising up to about 5 amino acid substitutions, an LC-CDR2 comprising the amino acid sequence of any one of SEQ ID NOs: 100-109, or a variant thereof comprising up to about 3 amino acid substitutions, and an LC-CDR3 comprising the amino acid sequence of any one of SEQ ID NOs: 110-119; or a variant thereof comprising up to about 5 amino acid substitutions.   
     
     
         9 : The isolated anti-AMC construct of  claim 8 , wherein the antibody moiety comprises a) a heavy chain variable domain comprising the amino acid sequence of any one of SEQ ID NOs: 17-26, or a variant thereof having at least about 95% sequence identify to any one of SEQ ID NOs: 17-26; and b) a light chain variable domain comprising the amino acid sequence of any one of SEQ ID NOs: 27-36, or a variant thereof having at least about 95% sequence identity to any one of SEQ ID NOs: 27-36. 
     
     
         10 : The isolated anti-AMC construct of  claim 1 , wherein the isolated anti-AMC construct is multispecific. 
     
     
         11 : The isolated anti-AMC construct of  claim 10 , wherein the isolated anti-AMC construct is a tandem scFv, a diabody (Db), a single chain diabody (scDb), a dual-affinity retargeting (DART) antibody, a dual variable domain (DVD) antibody, a knob-into-hole (KiH) antibody, a dock and lock (DNL) antibody, a chemically cross-linked antibody, a heteromultimeric antibody, or a heteroconjugate antibody. 
     
     
         12 : The isolated anti-AMC construct of  claim 11 , wherein the isolated anti-AMC construct is a tandem scFv comprising two scFvs linked by a peptide linker. 
     
     
         13 : The isolated anti-AMC construct of  claim 10 , wherein the isolated anti-AMC construct further comprises a second antibody moiety that specifically binds to a second antigen. 
     
     
         14 : The isolated anti-AMC construct of  claim 13 , wherein the second antigen is selected from the group consisting of CD3γ, CD3δ, CD3ε, CD3ζ, CD28, OX40, GITR, CD137, CD27, CD40L, and HVEM. 
     
     
         15 : The isolated anti-AMC construct of  claim 13 , wherein the second antigen is CD3ε, and wherein the isolated anti-AMC construct is a tandem scFv comprising an N-terminal scFv specific for the AFP/MHC class I complex and a C-terminal scFv specific for CD3ε. 
     
     
         16 : The isolated anti-AMC construct of  claim 1 , wherein the isolated anti-AMC construct is a chimeric antigen receptor comprising an extracellular domain comprising the antibody moiety, a transmembrane domain, and an intracellular signaling domain comprising a CD3ζ intracellular signaling sequence and a CD28 intracellular signaling sequence. 
     
     
         17 : The isolated anti-AMC construct of  claim 1 , wherein the isolated anti-AMC construct is an immunoconjugate comprising the antibody moiety and an effector molecule, wherein the effector molecule is a therapeutic agent selected from the group consisting of a drug, a toxin, a radioisotope, a protein, a peptide, and a nucleic acid. 
     
     
         18 : The isolated anti-AMC construct of  claim 1 , wherein the isolated anti-AMC construct is an immunoconjugate comprising the antibody moiety and a label. 
     
     
         19 : A pharmaceutical composition comprising the isolated anti-AMC construct of  claim 1 . 
     
     
         20 : A host cell expressing the isolated anti-AMC construct of  claim 1 . 
     
     
         21 : A nucleic acid encoding the polypeptide components of the isolated anti-AMC construct of  claim 1 . 
     
     
         22 : An effector cell expressing the isolated anti-AMC construct of  claim 16 . 
     
     
         23 . (canceled) 
     
     
         24 : A method of detecting a cell presenting a complex comprising an AFP peptide and an MHC class I protein on its surface, comprising contacting the cell with the isolated anti-AMC construct of  claim 18  and detecting the presence of the label on the cell. 
     
     
         25 : A method of treating an individual having an AFP-positive disease, comprising administering to the individual
 an effective amount of the pharmaceutical composition of  claim 19 .   
     
     
         26 - 27 . (canceled) 
     
     
         28 : A method of diagnosing an individual having an AFP-positive disease, comprising:
 a) administering an effective amount of the isolated anti-AMC construct of  claim 18  to the individual; and   b) determining the level of the label in the individual, wherein a level of the label above a threshold level indicates that the individual has the AFP-positive disease.   
     
     
         29 : A method of diagnosing an individual having an AFP-positive disease, comprising:
 a) contacting a sample derived from the individual with the isolated anti-AMC construct of  claim 18 ; and   b) determining the number of cells bound with the isolated anti-AMC construct in the sample, wherein a value for the number of cells bound with the isolated anti-AMC construct above a threshold level indicates that the individual has the AFP-positive disease.   
     
     
         30 - 34 . (canceled) 
     
     
         35 : A method of treating an individual having an AFP-positive disease, comprising administering to the individual an effective amount of the effector cell of  claim 22 .