ATB Therapeutics presented “atbodies,” antibody-peptide fusions designed to address ADC off-target toxicity and widen the therapeutic window. Speaking at the Antibody Engineering and Therapeutics conference in Basel, Switzerland, co-founder and chief business officer Max Houry described a catalytic payload intended to avoid membrane-crossing and limit damage to untargeted cells. ATB’s platform uses an enzymatic payload attached through a peptide linker, with the company emphasizing manufacturability as a core design constraint. Houry argued that the approach redefines ADC performance goals by focusing on potency delivered in small doses rather than cytotoxic payload spread. Preclinical in vitro data shared in the report indicated strong killing of non-targeted cells for a conventional ADC carrying MMAE, while the atbody showed substantially lower toxicity even at high dosing levels. The concept could inform how next-gen ADCs are engineered to satisfy both efficacy and safety expectations from regulators and clinicians.