PBS293

PBS293 (also known as PBS293-MMAE) is a first-in-class cis-bispecific antibody-drug conjugate (ADC) being developed by Promatix Biosciences. It consists of a full IgG1 bispecific antibody that simultaneously targets the Epidermal Growth Factor Receptor (EGFR) and Ephrin type-A receptor 2 (EphA2), conjugated to the cytotoxic payload monomethyl auristatin E (MMAE). The drug utilizes a dual-antigen 'AND-gate' targeting strategy with hybrid avidity-gated binding, which ensures that potent binding and payload internalization occur only when both target antigens are co-expressed on the same cell surface. This approach is designed to maximize tumor selectivity and therapeutic index while minimizing toxicities in healthy tissues that may express only one of the targets. Preclinical studies have demonstrated significant potency in KRAS-mutant colorectal cancer models and efficacy independent of RAS/BRAF mutation status, including in right-sided colorectal tumors.

Other names

EGFR x EphA2 bispecific ADC