Novel immunoconjugates

Abstract

The present invention generally relates to antigen-specific immunoconjugates for selectively delivering effector moieties that influence cellular activity. More specifically, the invention provides novel immunoconjugates comprising a first antigen binding moiety, an Fc domain and a single effector moiety. In addition, the present invention relates to polynucleotides encoding such immunoconjugates, and vectors and host cells comprising such polynucleotides. The invention further relates to methods for producing the immunoconjugates of the invention, and to methods of using these immunoconjugates in the treatment of disease.

1 . An immunoconjugate comprising (i) an immunoglobulin molecule comprising a first and a second antigen binding Fab molecule, an Fc domain consisting of two subunits, and (ii) an effector moiety, wherein not more than one effector moiety is present; and wherein
 said first and said second Fab molecule are directed to CEA and comprise a heavy chain variable region sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence of SEQ ID NO: 191, and a light chain variable region sequence that is at least about 95%, 96%, 97%, 98%, 99% or 100% identical to the sequence of SEQ ID NO: 189; and   said effector moiety is a mutant human interleukin-2 (IL-2) polypeptide comprising the amino acid substitutions F42A, Y45A, L72G, wherein numbering of the amino acid positions is relative to the human IL-2 sequence in SEQ ID NO: 2.   
     
     
         2 . The immunoconjugate of  claim 1 , wherein said effector moiety is fused to the carboxy-terminal amino acid of one of said two subunits of the Fc domain. 
     
     
         3 . (canceled) 
     
     
         4 . The immunoconjugate of  claim 1 , wherein said Fc domain comprises a modification promoting heterodimerization of two non-identical polypeptide chains, and wherein said modification is a knob-into-hole modification, comprising a knob modification in one of the subunits of the Fc domain and a hole modification in the other one of the two subunits of the Fc domain. 
     
     
         5 . The immunoconjugate of  claim 4 , wherein said knob modification comprises the amino acid substitution T366W, and said hole modification comprises the amino acid substitutions T366S, L368A and Y407V according to the EU numbering of Kabat. 
     
     
         6 . The immunoconjugate of  claim 5 , wherein the subunit of the Fc domain comprising the knob modification additionally comprises the amino acid substitution S354C, and the subunit of the Fc domain comprising the hole modification additionally comprises the amino acid substitution Y349C according to the EU numbering of Kabat. 
     
     
         7 . The immunoconjugate of  claim 4 , wherein said effector moiety is fused to the carboxy-terminal amino acid of the subunit of the Fc domain comprising the knob modification. 
     
     
         8 . (canceled) 
     
     
         9 . The immunoconjugate of  claim 1 , wherein said Fc domain is an IgG1 Fc domain. 
     
     
         10 - 13 . (canceled) 
     
     
         14 . The immunoconjugate of  claim 1 , wherein said Fc domain comprises one or more amino acid mutation that reduces the binding of the Fc domain to an Fcγ receptor. 
     
     
         15 . The immunoconjugate of  claim 14 , wherein said amino acid mutation is an amino acid substitution at position P329 according to the EU numbering of Kabat, or wherein the Fc domain comprises the amino acid substitutions L234A, L235A and P329G according to the EU numbering of Kabat in each of said two subunits. 
     
     
         16 - 18 . (canceled) 
     
     
         19 . The immunoconjugate of  claim 1 , wherein said Fc domain comprises an increased proportion of non-fucosylated oligosaccharides, as compared to a non-engineered Fc domain. 
     
     
         20 - 22 . (canceled) 
     
     
         23 . The immunoconjugate of  claim 1 , wherein said mutant human interleukin-2 (IL-2) polypeptide further comprises the amino acid substitution T3A, and/or the amino acid substitution C125A. 
     
     
         24 . (canceled) 
     
     
         25 . The immunoconjugate of  claim 1 , wherein said mutant human interleukin-2 (IL-2) polypeptide comprises the polypeptide sequence of SEQ ID NO: 3. 
     
     
         26 . The immunoconjugate of  claim 1 , comprising the polypeptide sequences of SEQ ID NO: 277, SEQ ID NO: 281 and SEQ ID NO: 283. 
     
     
         27 . An isolated polynucleotide encoding the immunoconjugate of  claim 1  or a fragment thereof. 
     
     
         28 . An expression vector comprising the isolated polynucleotide of  claim 27 . 
     
     
         29 . A host cell comprising the expression vector of  claim 28 . 
     
     
         30 . A method of producing an immunoconjugate comprising (i) an immunoglobulin molecule comprising a first and a second antigen binding Fab molecule and an Fc domain consisting of two subunits, and (ii) an effector moiety, wherein not more than one effector moiety is present, comprising culturing the host cell of  claim 29  under conditions suitable for the expression of the immunoconjugate. 
     
     
         31 . (canceled) 
     
     
         32 . A pharmaceutical composition comprising the immunoconjugate of  claim 26  and a pharmaceutically acceptable carrier. 
     
     
         33 . A method of treating a disease in an individual, comprising administering to said individual a therapeutically effective amount of a composition comprising the immunoconjugate of  claim 26  in a pharmaceutically acceptable form. 
     
     
         34 . The method of  claim 33 , wherein said disease is cancer or an inflammatory disorder. 
     
     
         35 . (canceled)