Experts propose suggestions to improve transparency of FDA complete response letters
The US Food and Drug Administration (FDA) could take additional steps to more successfully implement disclosures of complete response letters (CRLs) to the public, experts argued in a recent paper published in the Journal of Law and the Biosciences.
The recent decisions to publish batches of CRLs in July and September 2025 along with the commitment to publish CRLs in real time as they are issued showed the value of CRL disclosure, the authors said.
“I am a big believer that failures are, first and foremost, sources of knowledge. Non-approvals are no different: they are a source of regulatory knowledge,” Gabriela Lenarczyk, PhD, of the center for advanced studies in bioscience innovation law at the University of Copenhagen, told Focus in an interview. “CRLs can show, in FDA’s own words, what the principal problems were—and often what would be needed to resolve them.”
When FDA decides not to publish CRLs, developers are left to primarily rely on sponsor statements, “which may be accurate but are, unsurprisingly, selective.”
“Publishing appropriately redacted CRLs can help developers learn from earlier review cycles, improve future submissions, and avoid repeating the same errors,” Lenarczyk said.
Lessons from EMA
Comparing FDA’s CRL system to the European Medicines Agency (EMA)’s approach to transparency around regulatory decision-making, the authors noted that FDA CRLs are a “raw and granular but redacted” communication to a sponsor, while an EMA European Public Assessment Reports (EPAR) is “more narrative and synthesized.” In the event of a refusal or withdrawal, EMA also usually publishes a refusal EPAR, a withdrawal assessment, or a public-facing Q&A depending on the circumstances—something which has no FDA counterpart.
FDA could take further actions to expand its commitment to transparency for CRLs in a way that approaches EMA’s system, including creating a disclosure timeline, redaction standards, and retrospective transparency, among other initiatives.
The disclosure timeline could be a guidance or regulation that states FDA’s commitment to posting a CRL within a certain timeframe after it is issued to a sponsor. “Adding a defined publication deadline, an update log, short neutral summaries, and structured metadata is principally a matter of workflow and resourcing,” Lenarczyk told Focus. “I imagine that reviewing and redacting the historical record for applications that remain unapproved, withdrawn, or abandoned would require more resources, but FDA could begin with the staged pilot we propose for high-salience original NDAs and BLAs.”
The agency should also create redaction standards at the same time that follow “existing legal standards for trade secrets and confidential commercial information,” and publish neutral summaries of why an application was not approved in the event redactions make a CRL unreadable.
FDA could use EMA’s approach of requiring applicants to justify proposed commercial-confidentiality redactions and give the agency the final decision whether to follow through with a redaction. “In the FDA context, this could take the form of a short sponsor-notice process in which applicants identify proposed redactions with page-and-line specificity and explain why particular material constitutes a trade secret or confidential commercial information,” Lenarczyk explained.
Lenarczyk said FDA’s FY2027 request for explicit statutory authority and planned rulemaking for proactive CRL disclosure make her “cautiously optimistic” on the feasibility of implementing these suggestions.
She also noted that the US and European Union (EU) could “move closer together in recognizing that transparency and commercial confidentiality are not mutually exclusive.”
“We already have tools, including targeted redactions, to protect information that genuinely warrants protection while still allowing regulatory documents to contribute to further learning and development,” she said. “Rather than viewing transparency only as a public-accountability measure or as an ethical or moral principle, I would like to see it recognized for what it is increasingly becoming—and, to a significant extent, already is in the EU: regulatory infrastructure.”
