Non-approval in the sunlight: FDA's CRL disclosures, the limits of confidentiality, and lessons from the EMA

The US Food and Drug Administration (FDA) issues complete response letters (CRLs) after completing a review when it determines that it cannot approve a drug or biological product application in its current form. Historically, the FDA has treated CRLs as confidential, leaving sponsors largely in control of how non-approval decisions are described publicly. This approach has been criticized for relying on an expansive view of confidentiality, which can obscure safety, efficacy, and quality-related concerns, and for enabling selective or incomplete sponsor communications. In 2025, the FDA shifted course. On July 10, 2025, the FDA posted more than 200 CRLs tied to applications that had subsequently been approved, consolidating information that was often already embedded in the approval action packages. On September 4, 2025, the FDA released 89 previously unpublished CRLs for pending or withdrawn applications, and committed to real-time disclosure of newly issued CRLs going forward. Using a comparative FDA-European Medicines Agency (EMA) lens, we assess what these initiatives changed at launch and how early implementation through May 2026 affects their durability, legal footing, and information value. By May 2026, the FDA's CRL initiative had evolved into a functioning yet unsettled disclosure infrastructure: openFDA now offers searchable access to CRLs for approved and unapproved applications, while the FDA's FY 2027 budget request simultaneously seeks clearer statutory authority to disclose certain information in CRLs. We argue that FDA CRLs and EMA assessment outputs are complementary, and we propose lessons that FDA can learn from the EMA to maximize the value of CRL disclosure: codifying timelines and redaction standards, adding neutral decisional summaries where redactions or technical language would otherwise obscure the basis for non-approval, and standardizing the classification and discoverability of prior-cycle CRLs in approval packages. These reforms can protect legitimate confidential commercial information while enabling learning from unsuccessful applications.