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# Guide on Seeing if Confirmatory Study Underway
- URL: https://www.fdaweb.com/guide-on-seeing-if-confirmatory-study-underway/
- Published: 2025-01-06T12:00:00.000Z
- Updated: 2026-09-14T14:50:11.000Z
- Author: David McFarland
- Tags: Drugs, #legacy-id-D5158429

FDA has posted a draft guidance entitled “Accelerated Approval and Considerations for Determining Whether a Confirmatory Trial is Underway.” The document addresses the agency’s recent requirement that sponsors of an accelerated-approval drug/biologic must have their confirmatory trial underway at the time of approval. The requirement was mandated in the Consolidated Appropriations Act of 2023 to address the slowness of some sponsors in conducting and completing a confirmatory trial.

This guidance describes FDA’s interpretation of the term “underway,” and factors it intends to consider when determining whether a confirmatory trial is underway prior to approval. It says that “FDA generally intends to consider a confirmatory trial to be underway prior to accelerated approval if (**1**) the trial has a target completion date that is consistent with diligent and timely conduct of the trial, considering the nature of the trial’s design and objectives, (**2)** the sponsor’s progress and plans for postapproval conduct of the trial provide sufficient assurance to expect timely completion of the trial, and (**3**) enrollment of the confirmatory trial has been initiated.”

It notes that there may be limited circumstances where FDA may not require the confirmatory trial to be underway prior to accelerated approval. “For example, the confirmatory trial may be dependent on a future event, e.g., an infectious disease outbreak that has not yet occurred and at the time of approval it would be infeasible to conduct a trial,” the guidance says

“For certain rare diseases, the clinically relevant endpoints and disease natural history may enable postmarketing studies that do not require randomization to verify clinical benefit, and this design could reduce the challenge of enrolling and completing the study if it is not underway prior to approval,” it says. “FDA also recognizes that sponsors seeking approval for drugs intended to treat some rare diseases, especially those with very small populations with high unmet need, may face unique challenges with initiating postapproval confirmatory trials prior to approval. In these circumstances, if appropriate justification is provided, FDA may not require that the confirmatory trial is ‘underway’ prior to accelerated approval.”

FDA encourages sponsors to have early discussions with reviewers on the plan and timeline for a postapproval trial, including the proposed study design to verify benefit, timing for initiation of the confirmatory study, and appropriate justification for the plan and timeline. “The timeline for confirmatory trial completion should reflect timely completion of the trial, including diligent conduct of the trial by the sponsor in a manner that limits the amount of time the drug will remain approved without verification of clinical benefit,” it says.

The guidance says that considerations that may impact a target trial completion date include:

![](https://ssl.gstatic.com/ui/v1/icons/mail/images/cleardot.gif)

- Natural history of the disease (e.g., rate of disease progression)
- Availability of alternative treatments (e.g., impact of alternative treatments on study participant recruitment before and after accelerated approval of the drug)
- Anticipated recruitment timeline (including consideration of potential challenges with enrolling or retaining participants in the trial post-accelerated approval,
- Projected timeline for efficacy analysis(es), taking into consideration event rates and/or minimum follow-up required, depending on the outcome(s) of interest