What Is Considered a Clinical Trial? Approval Required Before Starting a Clinical Trial Single Combined Application Process Key Timelines For applications involving consultation with specialist groups or advanced therapy medicinal products (ATMPs), review timelines may extend up to 120 calendar days. Approval With Conditions Appeals Process Key Application Documents The application package must include a detailed cover letter containing: The updated UK framework aims to streamline clinical trial approvals while strengthening regulatory oversight, participant safety, and data reliability.