TY - JOUR T1 - Antibody-drug conjugates with dual payloads for combating breast tumor heterogeneity and drug resistance JF - bioRxiv DO - 10.1101/2020.12.18.423326 SP - 2020.12.18.423326 AU - Chisato M. Yamazaki AU - Aiko Yamaguchi AU - Yasuaki Anami AU - Wei Xiong AU - Yoshihiro Otani AU - Jangsoon Lee AU - Naoto T. Ueno AU - Ningyan Zhang AU - Zhiqiang An AU - Kyoji Tsuchikama Y1 - 2020/01/01 UR - http://biorxiv.org/content/early/2020/12/21/2020.12.18.423326.abstract N2 - Breast tumors generally consist of a diverse population of cells with varying gene expression profiles. Breast tumor heterogeneity is a major factor contributing to drug resistance, recurrence, and metastasis after chemotherapy. Antibody-drug conjugates (ADCs) are emerging chemotherapeutic agents with striking clinical success, including T-DM1 for HER2-positive breast cancer. However, these ADCs often suffer from issues associated with intratumor heterogeneity. Here, we show that homogeneous ADCs containing two distinct payloads are a promising drug class for addressing this clinical challenge. Our conjugates show HER2-specific cell killing potency, desirable pharmacokinetic profiles, minimal immunogenicity, and marginal toxicity at therapeutic doses. Notably, a dual-drug ADC exerts greater treatment effect and survival benefit than does co-administration of two single-drug variants in a xenograft mouse model representing intratumor HER2 heterogeneity and elevated drug resistance. Our findings highlight the therapeutic potential of the dual-drug ADC format for treating refractory breast cancer and perhaps other cancers.Competing Interest StatementC.M.Y. and A.Y. contributed equally to the work. K.T. conceived the project rationale and supervised all experiments. C.M.Y., A.Y., and K.T. designed experiments. W.X., N.Z., and Z.A. produced mutated monoclonal antibodies. A.Y. and Y.A. prepared and characterized linkers and payload components. A.Y. constructed and characterized antibody conjugates. C.M.Y., J.L., N.T.U., and K.T. established drug-resistant cell lines. C.M.Y., A.Y., Y.A., and J.L. performed in vitro assays. C.M.Y. performed pharmacokinetic studies and xenograft studies. C.M.Y. and Y.O. performed tissue imaging and analysis. C.M.Y., A.Y., Y.A., and K.T. wrote the paper. ER -