A Polar Sulfamide Spacer Significantly Enhances the Manufacturability, Stability, and Therapeutic Index of Antibody–Drug Conjugates

• Published in: Antibodies (Basel) Vol. 7; no. 1; p. 12
• Main Authors: Verkade, Jorge, Wijdeven, Marloes, Van Geel, Remon, Janssen, Brian, Van Berkel, Sander, Van Delft, Floris
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 20-02-2018; MDPI
• Subjects: antibody–drug conjugates (ADCs); Cancer; carbamoyl sulfamide; chemoenzymatic; Conjugates; Conjugation; copper-free click chemistry; Design for manufacturability; glycan-remodeling; Manufacturability; Pharmacokinetics; Pharmacology; Spacer; spacer technology; Stability; Sulfamide; therapeutic index; Toxins
• ISSN: 2073-4468; 2073-4468
• DOI: 10.3390/antib7010012

Despite tremendous efforts in the field of targeted cancer therapy with antibody–drug conjugates (ADCs), attrition rates have been high. Historically, the priority in ADC development has been the selection of target, antibody, and toxin, with little focus on the nature of the linker. We show here that a short and polar sulfamide spacer (HydraSpace™, Oss, The Netherlands) positively impacts ADC properties in various ways: (a) efficiency of conjugation; (b) stability; and (c) therapeutic index. Different ADC formats are explored in terms of drug-to-antibody ratios (DAR2, DAR4) and we describe the generation of a DAR4 ADC by site-specific attachment of a bivalent linker–payload construct to a single conjugation site in the antibody. A head-to-head comparison of HydraSpace™-containing DAR4 ADCs to marketed drugs, derived from the same antibody and toxic payload components, indicated a significant improvement in both the efficacy and safety of several vivo models, corroborated by in-depth pharmacokinetic analysis. Taken together, HydraSpace™ technology based on a polar sulfamide spacer provides significant improvement in manufacturability, stability, and ADC design, and is a powerful platform to enable next-generation ADCs with enhanced therapeutic index.