After your Phase III trial closes, every protocol decision, patient case, and data point you recorded converges into a single document that regulators use to decide drug approval: the Clinical Study Report, or CSR. Unlike a journal article or summary, a full CSR can run hundreds or even a thousand pages for complex late-stage trials. It follows the ICH E3 guideline and sits in Module 5 of the regulatory submission dossier.
For sites, understanding the CSR process matters because your source documents, deviation logs, case report forms, adverse event narratives, and ethics approvals feed directly into this report. Incomplete or inconsistent records at the site level can surface as regulatory queries or delays during agency review. The CSR pulls from clinical operations, biostatistics, data management, pharmacovigilance, and medical writing, all working from the foundation you built during trial conduct. Different study phases use different CSR formats, from full reports for pivotal trials to abbreviated versions for PK or early safety studies. Supplemental CSRs may be needed later for delayed or exploratory analyses, meaning your trial documentation remains relevant long after your last patient visit.