This blog explores the EMA’s revised CTIS transparency rules, the increase in clinical trial transitions to the Clinical Trial Regulation (CTR), and how the new publication framework (introduced in June 2024) aimed to simplify trial disclosure, reduce redaction burdens, and improve access to meaningful clinical trial information.
Clinical trial applications that were transitioned to the Clinical Trial Regulation
Of the 5,088 transitional applications submitted during the transitional period, 62 were submitted (1.2%) in 2022, 569 (11.2%) in 2023, 4,303 (84.6%) in 2024 and 154 (3.0%) by 30 January 2025.1
We previously wrote about the landscape of European clinical trials 3 years on from the transition to the CTR.
Although the entire transition period from the CTD to the CTR was three years, the number of clinical trials that transitioned was substantially higher in 2024 than in 2023, which may have coincided with the EMA’s loosened guidance on transparency and deferral rules in the CTIS database.
Transparency rules for clinical trial sponsors
When CTIS was launched in 2022, it did so with transparency rules outlined in the “Appendix on disclosure rules,” requiring broad publication of clinical trial application dossiers and lifecycle information while ensuring protection of personal data and commercially confidential information (CCI).
To support this, the system allowed submission of “for publication” and “not for publication” document versions,2 initially intended for personal data protection but used in practice to shield CCI. Additionally, the framework introduced a deferral mechanism linked to a categorisation of trials, recognising that different trial types contain varying levels of CCI depending on development stage. These categories determined the length of deferral periods, enabling sponsors to delay publication of sensitive information, notably key documents such as protocols, until the end of the deferral period, triggered by the trial’s end in the EU/EEA, results submission, or CSR submission, allowing, in some cases, up to seven years of delayed disclosure.2
However, the deferral mechanism proved difficult to manage from both an information-management and data-security standpoint. The original transparency framework, requiring extensive publication of data and documents, including optional attachments, and not sufficiently prioritising information most relevant to patients and researchers, combined with complex system functionalities, affected how CTIS was used.2
Additionally, derogations for the disclosure of documents in paragraphs (c) and (d) of Article 81(4) of the CTR allowed Member States’ competent authorities to protect confidential communication between Member States concerning assessment report preparation. This resulted in draft assessment reports not being published.2
Also, redaction was applied to other documents in CTIs to protect sponsors’ CCI, which resulted in extensively redacted published documents being of little use to stakeholders and patients.
Revised transparency rules for clinical trial sponsors
The EMA’s revised transparency rules include a revised CTIS public website (the CTIS public portal), which launched in June 2024.2 The aim was to simplify access to clinical trial information by focusing publication on structured data and documents most relevant to patients and researchers, reducing system complexity and the need for extensive redactions. The EMA also removed the deferral procedure; instead, emphasis is now on redacting personal data and CCI from any publicly available documents.2
Revised transparency rules vs rules that remain the same
Revised publication rules for structured data fields
Structured data fields in CTIS are completed directly by sponsors and include predefined and free-text entries capturing key trial information such as titles, designs, eligibility criteria, endpoints, investigational products, trial sites, sponsor contacts, authorisation status, and relevant trial dates.2 These fields cannot be redacted, meaning no personal data or CCI should ever be included in them.
Revised publication rules for documents
Documents submitted through CTIS are published at the time of the application decision or upon submission, depending on their role, and may be redacted to protect CCI and personal data. CTIS allows sponsors to include two document versions: “for publication” (redacted) and “not for publication” (unredacted for regulatory review),2 and documents not intended for public release remain only in the secure domain. Under the revised transparency rules, publication is limited to documents most meaningful for patients and clinical researchers.
Summary
In the past three years, a total of 5,088 clinical trial applications were transitioned to the CTR, with most transitions occurring in 2024, potentially influenced by the EMA’s updated guidance on CTIS transparency and deferral rules. The original CTIS framework offered a publication deferral option and required broad publication of data while protecting personal and commercially confidential information, using dual document versions and a deferral mechanism. However, this approach proved complex, led to heavily redacted documents, and limited the usefulness of published information.
In June 2024, the EMA introduced revised transparency rules and a redesigned CTIS public website to simplify access to clinical trial information. The new approach removes deferrals, focuses publication on structured data and key documents relevant to patients and researchers, and reduces redaction burdens. Core CTR requirements, such as publication at application decision and alignment with WHO registry standards, remain unchanged, ensuring both improved usability and continued regulatory compliance.
