ADAPTNeg-ABD-mcDM1

**ADAPTNeg-ABD-mcDM1** is an experimental non-targeting albumin-binding domain-derived affinity protein drug conjugate developed as a negative-control comparator for the HER2-targeted conjugate ADAPT6-ABD-mcDM1. It comprises ADAPTNeg, an engineered scaffold protein designed not to bind a cellular target, fused to an albumin-binding domain to prolong systemic exposure and covalently linked through a noncleavable maleimidocaproyl linker to the maytansinoid cytotoxic payload mertansine. The construct is intended to distinguish nonspecific payload effects from HER2-mediated delivery in preclinical cancer models; it was administered intravenously in mice bearing HER2-expressing SKOV3 ovarian cancer xenografts.