Enzymatic conjugation of antibodies
The present application relates to methods for the functionalization of immunoglobulins, in particular with drugs. Also disclosed herein are linking reagents, functionalized antibodies, pharmaceutical compositions, and method of treating disease and/or conditions.
1. A method for attaching a lysine-based linker to an antibody, comprising:
a) providing a human or humanized antibody comprising one or more solvent exposed glutamine residues in a variable region and at least one acceptor glutamine residue in a constant region or in a sequence fused to a constant region or fused to a variable region, wherein said one or more solvent exposed glutamine residues are present in a light chain variable domain (VL) CDR at a Kabat position selected from the group consisting of 27, 55, and a combination thereof; and
b) reacting said antibody with a lysine-based linker in the presence of a transglutaminase, under conditions permitting said lysine-based linker to be covalently linked to said at least one acceptor glutamine residue in a constant region or in a sequence fused to a constant region or fused to a variable region in said human or humanized antibody.
2. The method of claim 1 , wherein the antibody comprises:
a heavy chain framework region 1 (FR-H1) comprising a glutamine residue at Kabat position 1, 3, 5, 6, 10, 11, 12, 13 and/or 16;
a heavy chain framework region 2 (FR-H2) comprising a glutamine residue at Kabat position 38, 39, 43 and/or 45; and/or
a heavy chain framework region 3 (FR-H3) comprising a glutamine residue at Kabat position 66, 75, 77, 81 and/or 85.
3. The method of claim 1 , wherein said lysine-based linker comprises a reactive group (R) selected from the group consisting of an azide, an alkyne, a tetrazine, a norbornene, another strained or otherwise electronically activated alkene, a substituted cycloalkyne, and an unsubstituted cycloalkyne.
4. The method of claim 3 , further comprising reacting the antibody having said lysine-based linker attached to said acceptor glutamine in a constant region or in a sequence fused to a constant region or fused to a variable region in said human or humanized antibody, with a compound comprising a reactive group (R′) capable of reacting with the reactive group R of said lysine-based linker and a moiety of interest (Z), under conditions sufficient to produce an antibody comprising an acceptor glutamine linked to the moiety of interest (Z) via a lysine-based linker.
5. The method of claim 4 , wherein R′ is selected from the group consisting of an azide, an alkyne, a tetrazine, a norbornene, another strained or otherwise electronically activated alkene, a substituted cycloalkyne, and an unsubstituted cycloalkyne.
6. The method of claim 4 , wherein Z comprises a large chemical entity, a negatively charged chemical entity, a hydrophobic chemical entity, or a combination thereof.
7. The method of claim 4 , wherein Z is selected from the group consisting of taxanes, anthracyclines, camptothecins, epothilones, mytomycins, combretastatins, vinca alkaloids, nitrogen mustards, maytansinoids, calicheamycins, duocarmycins, tubulysins, amatoxins, dolastatins, auristatins, enediynes, pyrrolobenzodiazepines, radioisotopes, therapeutic proteins, toxins and fragments thereof.
8. The method of claim 4 , wherein conjugation of the moiety of interest (Z) does not occur on a glutamine within the variable region.
9. The method of claim 6 , wherein said method comprises conjugating one or more moieties-of interest (Z) to an acceptor glutamine residue in a constant region or in a sequence fused to a constant region or fused to a variable region of said human or humanized antibody, wherein said one or more moieties-of-interest (Z) are conjugated through a linker that comprises a NH—(C) n -moiety,
wherein
(C) n is a substituted or unsubstituted alkyl chain, a substituted or unsubstituted heteroalkyl chain, wherein any carbon of the chain is unsubstituted or substituted with an alkoxy, hydroxyl, alkylcarbonyloxy, alkyl-S—, thiol, alkyl-C(O)S—, amine, alkylamine, amide, or alkylamide, and n is an integer selected from among the range of 2 to 20; and
Z is a reactive moiety or a moiety that improves the pharmacokinetic properties, a therapeutic moiety or a diagnostic moiety.
10. The method of claim 9 , wherein at least 70%, 80% or 90% of the antibodies produced by said method have (m) moieties of interest (Z) conjugated to acceptor glutamine residues (Q) per antibody, wherein m is an integer selected from 2 or 4.
11. The method of claim 1 , wherein said lysine-based linker is covalently linked to at least one acceptor glutamine in said constant region of said human or humanized antibody.
12. The method of claim 9 , wherein n is an integer selected from among the range of 6 to 20.
13. The method of claim 9 , wherein said human or humanized antibody comprises:
a heavy chain framework region 1 (FR-H1) comprising a glutamine residue at Kabat position 1, 3, 5, 6, 10, 11, 12, 13 and/or 16;
a heavy chain framework region 2 (FR-H2) comprising a glutamine residue at Kabat position 38, 39, 43 and/or 45; and/or
a heavy chain framework region 3 (FR-H3) comprising a glutamine residue at Kabat position 66, 75, 77, 81,and/or 85.