The United States of America (USA) clinical trials registry, ClinicalTrials.gov, is considered as a global platform for registering the clinical trials. It is not a World Health Organization (WHO) recognized primary registry. However, the clinical trials registered on this registry fulfill the criteria for publication of manuscript in an International Committee of Medical Journal Editors (ICMJE) accredited journal. In the USA, registration of protocols and submission of results is governed by the NIH Final Rule (42 CFR Part 11), which has been in effect since January 18, 2017. This regulation requires registration and results reporting for phase 2-4 interventional clinical trials.

Registries at a Glance
Registry	PHUSE Categorization	Information to be Entered By	Route of Data in Registry	Study Type	Language
ClinicalTrials.gov	Country requiring/recommending ClinicalTrials.gov use	Sponsor	Through a dedicated registration platform (process independent from clinical trial application)	Interventional (Phase 2-4)	English

Regulation effective since January 18, 2017
Registry Name	ClinicalTrials.gov
Requirement	Mandatory
Study Type	Interventional required Observational optional
Study Phase	2 to 4
When to Register	Within 21 days of the first subject enrollment
Timing of Registration	Prospective and Retrospective
Scope	Applicable clinical Trials (ACT) – Interventional Phase 2-4 clinical trials that are either investigational new drug (IND) or investigational device exemption (IDE) trials or conducted in the USA or study drug manufactured/exported from the USA
Registry Site	https://clinicaltrials.gov
Registration Site	https://register.clinicaltrials.gov/
Language	English
Data Fields	Protocol Data Elements
QA Review	Yes
Registration Publicly Available	Yes
Alternate Registry	No
Additional Details After submitting (releasing) a study record to ClinicalTrials.gov, it is reviewed by a ClinicalTrials.gov staff member before publishing, for apparent validity (when possible), meaningful entries, logic and internal consistency, and formatting. The review may take up to a few days. Reviewers can provide feedback, clarify items or make corrections to the record before publication. Registration records should be updated within 15 calendar days after feedback was provided. Once the study record is submitted and accepted by review staff for publication, a National Clinical Trial (NCT) Number is assigned. Then the record, including its NCT Number, will be available on ClinicalTrials.gov within 2–5 business days. Registration should be updated within 30 days of a change to any of the following: Individual Site Status and Overall Recruitment Status data elements on ClinicalTrials.gov. Primary Completion Date data elements on ClinicalTrials.gov. Other changes or updates to the record must be made at least every 12 months. It is recommended that the Record Verification Date be updated at least every 6 months for studies that are not yet completed, even if there were no changes to the record. There are no requirements for registration of observational studies. In general, clinical trial registration information submitted to ClinicalTrials.gov must be updated not less than once every 12 months. There are no legal requirements for registration of interventional Phase 1 or observational clinical trials. However, sponsors can voluntarily register such trials. The expanded access (EA) record for investigational drug or biological product must be submitted based on when the EA becomes available:  After the ACT information is submitted: no later than 30 calendar days after it becomes available.  At the time of ACT information submission: no later than the ACT registration deadline (within 21 calendar days of first enrollment).

Regulation effective since January 18, 2017
Registry Name	ClinicalTrials.gov
Requirement	Mandatory
Study Type	Interventional required Observational optional
Study Phase	2 to 4
Product Marketing Status	Approved or Unapproved
When to Post	Primary Results - within one year of primary completion date (PCD); Subsequent Results - within one year of the last subject last visit for each secondary outcome measure (SOM); Final Results - within one year of the study completion date
Scope	Applicable Clinical Trials (ACT) – Interventional Phase 2-4 clinical trials that are either investigational new drug (IND) or investigational device exemption (IDE) trials or conducted in the USA or study drug manufactured/exported from the USA
Registry Site	https://clinicaltrials.gov
Registration Site	https://register.clinicaltrials.gov
Language	English
Data Fields	Results Data Elements
QA Review	Yes
Results Publicly Available	Yes
Alternate Registry	No
Additional Details A ClinicalTrials.gov staff member will review the study record after it is submitted and before it is posted on ClinicalTrials.gov for apparent validity (when possible), meaningful entries, logic and internal consistency, and formatting. For those applicable clinical trials with a PCD on or after January 18, 2017, a redacted copy of the protocol and statistical analysis plan (SAP) should be submitted as a part of clinical trial result information. Delayed results: In case product is not approved at the time of PCD and PCD is on or after 18 Jan 2017, results can be delayed by filing the delayed certification:  The product under study was not FDA-approved before the PCD: No later than 30 days after approval, licensed or cleared by FDA. The clinical trial studies for new use of the previously approved product and the application or premarket notification that has been filed or will be filed within 1 year: No later than 30 days after the new use of the drug or device is approved, licensed, or cleared by FDA or FDA issues a letter for the new use or the application or premarket notification for the new use is withdrawn without resubmission within 210 days. The delayed certification should be submitted one day prior to the due date of primary result posting. As of February 1, 2021, the PRS no longer permits late submission of delayed certifications for ACTs with a primary completion date on or after January 18, 2017. The delayed certification for good cause extension should be submitted one day prior to the due date of primary result posting. As of January 25, 2022, the PRS no longer permits late submission of delayed certifications for good cause extension for ACTs with a primary completion date on or after January 18, 2017. The maximum deadline for results information submission is 2 years after the date on which the certification was submitted. Reviewers can provide feedback, clarify items or make corrections to the record before publication. Results should be updated within 25 calendar days after feedback was provided.

Timeline for Disclosure

Figure 1: Timeline of Clinical Trial Disclosures in the USA

Upcoming Changes

Registry Updates

• September 2022: What’s New on ClinicalTrials.gov - On September 26, 2022, the following update was posted on the  ClinicalTrials.gov What’s New section: A Plain Language checklist for Lay Brief Summaries was added to the support materials under Data Element Definitions, Templates, and Checklists section. This checklist identifies plain language best practices to help investigators write brief summaries that can be easily understood … Continue reading "September 2022: What’s New on ClinicalTrials.gov"
• August 2022: What’s New on ClinicalTrials.gov - On August 23, 2022, the below update was posted on ClinicalTrials.gov What’s New section, regarding the updates made to the ClinicalTrials.gov Beta website and clarification on the FAQ related to the requirement on submitting results for a Non-applicable Clinical Trial. ClinicalTrials.gov Beta Website: In addition to improved search for clinical studies and a tabular view … Continue reading "August 2022: What’s New on ClinicalTrials.gov"
• July 2022: What’s New on ClinicalTrials.gov PRS Beta - The below update was posted on the What’s New section of ClinicalTrials.gov PRS test system on July 14, 2022. Two new record list views in PRS beta, the Planning View and the Public Site View, are now accessible for PRS administrators in the PRS.

References