AbClick Pro H: Scavenger-Free, Traceless Lys248 Conjugation Via <i>O</i> -Acyl Hydroxamate Chemistry for Homogeneous Antibody–Drug Conjugates (ADCs)

A traceless <i>O</i>-acyl hydroxamate Fc-binding peptide linker enables rapid, scavenger-free, and site-selective conjugation at Lys248 of human IgG₁. The resulting homogeneous DAR2 antibody-drug conjugates (ADCs) retain antigen binding and internalization with payload-dependent stability and cytotoxicity. The linker's intrinsic leaving-group mechanism ensures clean FcBP release and broad payload compatibility. This robust, scalable traceless Lys248 conjugation chemistry underpins investigational new drug (IND)-approved and nonclinical ADC pipelines, offering a predictable platform for next-generation ADC design.