A branched linker-payload is an advanced molecular design used primarily in the development of antibody-drug conjugates (ADCs). It features a central branching point that enables a single antibody attachment site to carry multiple functional moieties, such as cytotoxic payloads and solubilizing PEG arms. This design can improve aqueous solubility, enhance conjugate stability, and reduce aggregation.
In conventional ADCs, a linear linker connects a single payload to a single antibody conjugation site. In contrast, a branched linker functions like a molecular multi-adapter. It consists of a main stem that attaches to the antibody and bifurcates into two or more distinct arms, allowing the incorporation of multiple payloads or other functional groups. This architecture enables higher payload loading and greater flexibility in ADC design while maintaining controlled and site-specific conjugation.