title: In Vitro and In Vivo Evaluation of Cysteine Rebridged Trastuzumab-MMAE Antibody Drug Conjugates with Defined Drug-to-Antibody Ratios.
abstract: The conjugation of monomethyl auristatin E (MMAE) to trastuzumab using a reduction bis-alkylation approach that is capable of rebridging reduced (native) antibody interchain disulfide bonds has been previously shown to produce a homogeneous and stable conjugate with a drug-to-antibody ratio (DAR) of 4 as the major product. Here, we further investigate the potency of the DAR 4 conjugates prepared by bis-alkylation by comparing to lower drug loaded variants to maleimide linker based conjugates possessing typical mixed DAR profiles. Serum stability, HER2 receptor binding, internalization, in vitro potency, and in vivo efficacy were all evaluated. Greater stability compared with maleimide conjugation was observed with no significant decrease in receptor/FcRn binding. A clear dose-response was obtained based on drug loading (DAR) with the DAR 4 conjugate showing the highest potency in vitro and a much higher efficacy in vivo compared with the lower DAR conjugates. Finally, the DAR 4 conjugate demonstrated superior efficacy compared to trastuzumab-DM1 (T-DM1, Kadcyla), as evaluated in a low HER2 expressing JIMT-1 xenograft model.
authors.affiliation: †PolyTherics Ltd. and ‡Antitope Ltd., Abzena, Babraham Research Campus, CB22 3AT Cambridge, United Kingdom.
authors.forename: Penny
authors.initials: P
authors.lastname: Bryant
authors.affiliation: †PolyTherics Ltd. and ‡Antitope Ltd., Abzena, Babraham Research Campus, CB22 3AT Cambridge, United Kingdom.
authors.forename: Martin
authors.initials: M
authors.lastname: Pabst
authors.affiliation: †PolyTherics Ltd. and ‡Antitope Ltd., Abzena, Babraham Research Campus, CB22 3AT Cambridge, United Kingdom.
authors.forename: George
authors.initials: G
authors.lastname: Badescu
authors.affiliation: †PolyTherics Ltd. and ‡Antitope Ltd., Abzena, Babraham Research Campus, CB22 3AT Cambridge, United Kingdom.
authors.forename: Matthew
authors.initials: M
authors.lastname: Bird
authors.affiliation: †PolyTherics Ltd. and ‡Antitope Ltd., Abzena, Babraham Research Campus, CB22 3AT Cambridge, United Kingdom.
authors.forename: William
authors.initials: W
authors.lastname: McDowell
authors.affiliation: †PolyTherics Ltd. and ‡Antitope Ltd., Abzena, Babraham Research Campus, CB22 3AT Cambridge, United Kingdom.
authors.forename: Estera
authors.initials: E
authors.lastname: Jamieson
authors.affiliation: †PolyTherics Ltd. and ‡Antitope Ltd., Abzena, Babraham Research Campus, CB22 3AT Cambridge, United Kingdom.
authors.forename: Julia
authors.initials: J
authors.lastname: Swierkosz
authors.affiliation: †PolyTherics Ltd. and ‡Antitope Ltd., Abzena, Babraham Research Campus, CB22 3AT Cambridge, United Kingdom.
authors.forename: Kosma
authors.initials: K
authors.lastname: Jurlewicz
authors.affiliation: †PolyTherics Ltd. and ‡Antitope Ltd., Abzena, Babraham Research Campus, CB22 3AT Cambridge, United Kingdom.
authors.forename: Rita
authors.initials: R
authors.lastname: Tommasi
authors.affiliation: †PolyTherics Ltd. and ‡Antitope Ltd., Abzena, Babraham Research Campus, CB22 3AT Cambridge, United Kingdom.
authors.forename: Korinna
authors.initials: K
authors.lastname: Henseleit
authors.affiliation: †PolyTherics Ltd. and ‡Antitope Ltd., Abzena, Babraham Research Campus, CB22 3AT Cambridge, United Kingdom.
authors.forename: XiaoBo
authors.initials: X
authors.lastname: Sheng
authors.affiliation: †PolyTherics Ltd. and ‡Antitope Ltd., Abzena, Babraham Research Campus, CB22 3AT Cambridge, United Kingdom.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Camper
authors.affiliation: †PolyTherics Ltd. and ‡Antitope Ltd., Abzena, Babraham Research Campus, CB22 3AT Cambridge, United Kingdom.
authors.forename: Anais
authors.initials: A
authors.lastname: Manin
authors.affiliation: †PolyTherics Ltd. and ‡Antitope Ltd., Abzena, Babraham Research Campus, CB22 3AT Cambridge, United Kingdom.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Kozakowska
authors.affiliation: †PolyTherics Ltd. and ‡Antitope Ltd., Abzena, Babraham Research Campus, CB22 3AT Cambridge, United Kingdom.
authors.forename: Karolina
authors.initials: K
authors.lastname: Peciak
authors.affiliation: †PolyTherics Ltd. and ‡Antitope Ltd., Abzena, Babraham Research Campus, CB22 3AT Cambridge, United Kingdom.
authors.forename: Emmanuelle
authors.initials: E
authors.lastname: Laurine
authors.affiliation: †PolyTherics Ltd. and ‡Antitope Ltd., Abzena, Babraham Research Campus, CB22 3AT Cambridge, United Kingdom.
authors.forename: Ruslan
authors.initials: R
authors.lastname: Grygorash
authors.affiliation: †PolyTherics Ltd. and ‡Antitope Ltd., Abzena, Babraham Research Campus, CB22 3AT Cambridge, United Kingdom.
authors.forename: Andrew
authors.initials: A
authors.lastname: Kyle
authors.affiliation: †PolyTherics Ltd. and ‡Antitope Ltd., Abzena, Babraham Research Campus, CB22 3AT Cambridge, United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Morris
authors.affiliation: †PolyTherics Ltd. and ‡Antitope Ltd., Abzena, Babraham Research Campus, CB22 3AT Cambridge, United Kingdom.
authors.forename: Vimal
authors.initials: V
authors.lastname: Parekh
authors.affiliation: †PolyTherics Ltd. and ‡Antitope Ltd., Abzena, Babraham Research Campus, CB22 3AT Cambridge, United Kingdom.
authors.forename: Amrita
authors.initials: A
authors.lastname: Abhilash
authors.affiliation: †PolyTherics Ltd. and ‡Antitope Ltd., Abzena, Babraham Research Campus, CB22 3AT Cambridge, United Kingdom.
authors.forename: Ji-Won
authors.initials: JW
authors.lastname: Choi
authors.affiliation: †PolyTherics Ltd. and ‡Antitope Ltd., Abzena, Babraham Research Campus, CB22 3AT Cambridge, United Kingdom.
authors.forename: Jeff
authors.initials: J
authors.lastname: Edwards
authors.affiliation: †PolyTherics Ltd. and ‡Antitope Ltd., Abzena, Babraham Research Campus, CB22 3AT Cambridge, United Kingdom.
authors.forename: Mark
authors.initials: M
authors.lastname: Frigerio
authors.affiliation: †PolyTherics Ltd. and ‡Antitope Ltd., Abzena, Babraham Research Campus, CB22 3AT Cambridge, United Kingdom.
authors.forename: Matthew P
authors.initials: MP
authors.lastname: Baker
authors.affiliation: †PolyTherics Ltd. and ‡Antitope Ltd., Abzena, Babraham Research Campus, CB22 3AT Cambridge, United Kingdom.
authors.forename: Antony
authors.initials: A
authors.lastname: Godwin
mesh_terms: D000818:Animals; D045744:Cell Line, Tumor; D003545:Cysteine / Q000737:chemistry*; D005260:Female; D006801:Humans; D018796:Immunoconjugates / Q000737:chemistry / Q000493:pharmacokinetics* / Q000627:therapeutic use*; D008325:Mammary Neoplasms, Experimental / Q000188:drug therapy*; D051379:Mice; D000068878:Trastuzumab / Q000737:chemistry*; D023041:Xenograft Model Antitumor Assays
chemical_list: D018796:Immunoconjugates; D003545:Cysteine; D000068878:Trastuzumab
keywords: JIMT-1 xenograft model; MMAE; antibody drug conjugates (ADC); auristatin; bis-alkylation; bis-sulfone; disulfide rebridging; drug loading; trastuzumab