title: Development and properties of beta-glucuronide linkers for monoclonal antibody-drug conjugates.
abstract: A beta-glucuronide-based linker for attaching cytotoxic agents to monoclonal antibodies (mAbs) was designed and evaluated. We employed the cytotoxic auristatin derivatives MMAE (1a) and MMAF (1b) and doxorubicin propyloxazoline (DPO, 2) to give the beta-glucuronide drug-linkers 9a, 9b, and 17, respectively. Cysteine-quenched derivatives of 9b and 17 were determined to be substrates for E. coli beta-glucuronidase, resulting in facile drug release. The beta-glucuronide MMAF drug-linker 9b was highly stable in rat plasma with an extrapolated half-life of 81 days. Each drug-linker when conjugated to mAbs c1F6 (anti-CD70) and cAC10 (anti-CD30) gave monomeric antibody-drug conjugates (ADCs) with as many as eight drugs per mAb and had high levels of immunologically specific cytotoxic activity on cancer cell lines. cAC10-9a displayed pronounced antitumor activity in a subcutaneous Karpas 299 lymphoma tumor model. A single dose treatment led to cures in all animals at the 0.5 mg/kg dose level and above, and the conjugate was well tolerated at 100 mg/kg. In mice with subcutaneous renal cell carcinoma xenografts, the MMAF conjugate c1F6-9b was tolerated at 25 mg/kg and efficacious at 0.75 mg/kg. These results demonstrate that the beta-glucuronide linker system is an effective strategy for targeting cytotoxic agents providing ADCs with high degrees of efficacy at well-tolerated doses.
authors.affiliation: Seattle Genetics, 21823 30th Drive SE, Bothell, Washington 98021, USA. sjeffrey@seagen.com
authors.forename: Scott C
authors.initials: SC
authors.lastname: Jeffrey
authors.forename: Jamie B
authors.initials: JB
authors.lastname: Andreyka
authors.forename: Starr X
authors.initials: SX
authors.lastname: Bernhardt
authors.forename: Kim M
authors.initials: KM
authors.lastname: Kissler
authors.forename: Toni
authors.initials: T
authors.lastname: Kline
authors.forename: Joel S
authors.initials: JS
authors.lastname: Lenox
authors.forename: Ruth F
authors.initials: RF
authors.lastname: Moser
authors.forename: Minh T
authors.initials: MT
authors.lastname: Nguyen
authors.forename: Nicole M
authors.initials: NM
authors.lastname: Okeley
authors.forename: Ivan J
authors.initials: IJ
authors.lastname: Stone
authors.forename: Xinqun
authors.initials: X
authors.lastname: Zhang
authors.forename: Peter D
authors.initials: PD
authors.lastname: Senter
mesh_terms: D000818:Animals; D000911:Antibodies, Monoclonal / Q000737:chemistry* / Q000276:immunology / Q000494:pharmacology* / Q000633:toxicity; D045744:Cell Line, Tumor; D002470:Cell Survival / Q000187:drug effects; D003432:Cross-Linking Reagents / Q000138:chemical synthesis* / Q000737:chemistry; D005260:Female; D020719:Glucuronides / Q000138:chemical synthesis / Q000737:chemistry*; D051379:Mice; D016513:Mice, SCID; D015394:Molecular Structure; D009369:Neoplasms / Q000276:immunology / Q000473:pathology; D013329:Structure-Activity Relationship
chemical_list: D000911:Antibodies, Monoclonal; D003432:Cross-Linking Reagents; D020719:Glucuronides