Regulatory teams are under more pressure than ever to submit clean, review-ready data. SEND has been mandatory for CDER nonclinical studies since 2017. Enforcement of Technical Rejection Criteria has been active since September 2021. By now, you would expect most submissions to be arriving at FDA without structural errors. The data says otherwise. Three years into active TRC enforcement, SEND continues to account for the majority of errors across every rejection code FDA trac

Introduction As SEND becomes more established in regulatory submissions to the U.S. FDA, expectations are evolving beyond basic dataset standardization toward greater transparency, expanded domain coverage, and improved support for regulatory review. With SENDIG v4.0 expected to be published in 2026, organizations preparing nonclinical submissions will need to adapt to a broader and more detailed set of requirements. These updates go beyond incremental changes and are likely