The Biotechnology Innovation Organization (BIO) submitted comments supporting the FDA’s proposed Plausible Mechanism Framework for individualized and disease-targeted therapies where traditional nonclinical or large randomized trial evidence is difficult to generate. BIO backed the Agency’s intent to create an alternative evidence pathway for safety and efficacy. In its letter, BIO urged refinements including broadening applicability beyond individualized products, adding operational clarity and definitions, adjusting chemistry, manufacturing and controls (CMC) expectations to match feasibility constraints, and strengthening recommendations around platform technologies and systematic use of prior knowledge. For developers, the framework—if implemented with predictable standards—could reduce trial-size barriers in rare diseases and enable more consistent regulatory decision-making across modalities.