Monoclonal antibodies (MAbs) remain the dominant biopharmaceutical product class, but as biotechnologies have advanced in recent decades, developers have found ways to exploit their “magic-bullet” capabilities while putting aside their limitations. That has led to a new generation of antibody-related therapeutics created by cutting and pasting molecular domains. Researchers are mixing and matching functional moieties of antibodies and other molecules to create custom-designed proteins with powerful efficacy and tunable targeting. A simple search at Taylor & Francis Online (https://www.tandfonline.com), the…

To meet the ongoing need for new and improved drugs, the biopharmaceutical community strives to create molecules with new functions. Bispecific antibodies (bsAbs), which can simultaneously home in on two different targets, illustrate the scientific ingenuity needed for this task. The basic proof of concept for these complex molecules was established in 1960 (1), and their application to the redirection of effector cells was reported in the mid-1980s (2–4), but producing them has proved to be challenging. Many technical advances,…