Paul Scherrer Institut

Eth Zurich

Martin Behe

Roger Schibli

Philipp Rene Spycher

Viola Vogel

David Hurwitz

Olivier Kreis

Samuel Hertig

Simon Arnoldini

Alessandra Moscaroli

Mamta Chabria

Jori Wehrmuller

Thomas Mindt

Nathalie Grob

The present invention relates to a method for generating an antibody-payload conjugate by means of a microbial transglutaminase (MTG). The method comprises a step of conjugating a linker having a primary amine residue, said linker having the peptide structure (shown in N->C direction) (Aax)-(Aax)(NH)-(Aax)-B-(Aax), or (Aax)-B-(Aax)-(Aax)(NH2)-(Aax), to a Gln residue comprised in the heavy or light chain of an antibody. Aax(NH) is an amino acid, amino acid derivative or amino acid mimetic comprising a side chain having a primary amine group.

Transglutaminase conjugation method and linker

The present invention is directed to a composition comprising at least one fibronectin binding polypeptide (FnBP) linked to at least one diagnostic or therapeutic agent, a nucleic acid encoding a fusion polypeptide comprising at least one fibronectin binding polypeptide (FnBP) linked to at least one diagnostic or therapeutic polypeptide agent as well as a corresponding recombinant vector and host cell comprising such a nucleic acid and preferably expressing said fusion polypeptide. The invention also relates to a kit of parts comprising at least one fibronectin binding polypeptide (FnBP), at least one diagnostic or therapeutic agent, and optionally one or more chemical agents for linking the fibronectin binding polypeptide (FnBP) to the diagnostic or therapeutic agent. In addition, the present invention intends said composition, nucleic acid, vector, host cell and kit for use in the therapeutic or prophylactic treatment of a disease, preferably a disease associated with abnormal fibronectin accumulation such as cancer, fibrosis or immune diseases.

Fibronectin-binding peptides for use in tumor or fibrosis diagnosis and therapy

A gastrin analogue shows high uptake in CCK-2 receptor positive tumors and simultaneously a very low accumulation in the kidneys. This is achieved by a mini-gastrin analogue PP-F11 having the formula: PP-F11-X-DGlu-DGlu-DGlu-DGlu-DGlu-DGlu-Ala-Tyr-Gly-Trp-Y-Asp-Phe-NH, wherein Y is an amino acid replacing methionine and X is a chemical group attached to the peptide for diagnostic and/or therapeutic intervention at CCK-2 receptor relevant diseases. Very suitable compounds with respect to a high tumor to kidney ratio are mini-gastrin analogues with six D-glutamic acids or six glutamines. These compounds still possess a methionine which can be oxidized easily which is a disadvantage for clinical application under GMP due to the forms which may occur. The elimination of the methionine leads to a lower affinity to oxidation which in general favors the tumor-kidney-ratio. Ideally, the methionine is replaced by norleucine. This PP-F11N mini gastrin exhibits currently the best tumor-kidney-ratio and is the most promising candidate.

Mini-gastrin analogue, in particular for use in CCK2 receptor positive tumour diagnosis and/or treatment

Site-specific modification of proteins with microbial transglutaminase (MTG) is a powerful and versatile strategy for a controlled modification of proteins under physiological conditions. Solid-phase microbead-immobilization is used to site-specifically and efficiently attach different functional molecules important for further downstream applications to proteins of therapeutic relevance including scFV, Fab-fragment and antibodies. MTG remained firmly immobilized with no detectable column bleeding and enzyme activity was sustained during continuous operation. Immobilized MTG shows enhanced selectivity towards a certain residue in the presence of several reactive residues which are all targeted when the conjugation was carried out in solution. The generation of dual site-specifically conjugated IgG1 with immobilized and MTG in solution is reported, i.e. site-specific conjugation to glutamine and lysine residues of IgG1 antibody. Site-specific glutamine conjugation with small peptides containing a lysine residue and a functional moiety is also described.

Site-specific conjugation to antibody lysine residues with solid-phase immobilized microbial transglutaminase MTG and MTG in solution

A gastrin analog shows high uptake in CCK-2 receptor positive tumors and simultaneously a very low accumulation in the kidneys. This is achieved by a mini-gastrin analog PP-F11 having the formula: PP-F11-X-DGlu-DGlu-DGlu-DGlu-DGlu-DGlu-Ala-Tyr-Gly-Trp-Y-Asp-Phe-NH, wherein Y is an amino acid replacing methionine and X is a chemical group attached to the peptide for diagnostic and/or therapeutic intervention at CCK-2 receptor relevant diseases. Very suitable compounds with respect to a high tumor to kidney ratio are mini-gastrin analogs with six D-glutamic acids or six glutamines. These compounds still possess a methionine which can be oxidized easily which is a disadvantage for clinical application under GMP due to the forms which may occur. The elimination of the methionine leads to a lower affinity to oxidation which in general favors the tumor-kidney-ratio. Ideally, the methionine is replaced by norleucine. This PP-F11N mini gastrin exhibits currently the best tumor-kidney-ratio and is the most promising candidate.

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Gelterkinden, Switzerland

Martin Behe