The US FDA Office of Biotechnology Products’ quality by design (QbD) pilot program defines an expanded change protocol (eCP) as a particular type of comparability protocol that will “describe the quality by design, risk- based approach linking attributes and processes to product performance safety, and efficacy” (1). Sponsors have explored a wide range of potential applications for eCPs (e.g., movement within or beyond an established design space, site transfers, and additional process modifications supported by either a QbD or traditional…