Usage Examples
- FDA put the Phase 1 dose escalation on partial clinical hold pending additional nonclinical toxicology.
- We are not dosing again until the hold is lifted in writing, complete response or not.
- The 30-day clock only starts when they receive a complete response, so a partial filing buys us nothing.
What is Clinical Hold?
A clinical hold is an FDA order under an IND that delays a proposed clinical investigation or suspends an ongoing one, halting dosing until the sponsor corrects the deficiencies FDA cited in writing.
A clinical hold exists because FDA needs a way to stop human dosing without terminating the IND outright. The order lets the agency freeze a specific investigation while the science is argued, rather than forcing a binary choice between letting an unsafe protocol run and killing the application. A clinical hold is therefore a pause with a defined path back.
A clinical hold covers investigations conducted under an IND and can be imposed on one or more of the studies that IND covers. It reaches proposed studies, which may not dose subjects, and ongoing ones, which stop recruiting and take patients off the investigational drug unless FDA permits otherwise for safety. A clinical hold does not withdraw the IND or touch marketed product.
A clinical hold usually arrives after a discussion. FDA will attempt to discuss and satisfactorily resolve the matter with the sponsor before issuing the order unless patients are exposed to immediate and serious risk. The sponsor then submits a complete response addressing every cited deficiency, and dosing resumes only after FDA notifies the sponsor that the investigation may proceed.
Not to be confused with
- IND termination
- termination ends the IND itself. A clinical hold suspends investigations while the IND stays alive, and the same order carries an explicit route back once FDA notifies the sponsor that the investigation may proceed.
- Partial clinical hold
- a partial hold is a clinical hold narrowed in scope to one study, dose level, or population. It is the same regulatory action with a smaller blast radius, not a lesser or informal one.
- Sponsor-initiated suspension
- a sponsor can pause its own trial at any time for safety or business reasons. Only FDA can issue a clinical hold, and only FDA can lift one; a voluntary pause carries no 30-day agency clock.
- Dispute resolution under 21 CFR 312.48
- 312.48 is the route for asking FDA to reconsider the decision. It is a separate procedure from the complete response, which corrects the deficiencies rather than contesting them.
The obligations sit on both sides. These are the anchors a sponsor is held to and the ones FDA owes back.
What you must do
- 1Stop dosing in the affected investigation when the order issues; a proposed study may not give subjects the drug, and an ongoing study stops recruiting and takes patients off the investigational drug unless FDA specifically permits otherwise in the interest of patient safety21 CFR 312.42(a)
- 2Address the specific ground FDA cited, whether unreasonable and significant risk of illness or injury, unqualified investigators, a misleading or materially incomplete investigator brochure, or an IND lacking sufficient information to assess risks to subjects21 CFR 312.42(b)(1)
- 3Work the pre-hold discussion, because FDA will attempt to discuss and satisfactorily resolve the matter before issuing the order unless patients are exposed to immediate and serious risk21 CFR 312.42(c)
- 4Submit a complete response covering every cited deficiency, then hold FDA to a written decision within 30 calendar days of receipt of the request and the complete response, and resume only on FDA's notice that the investigation may proceed21 CFR 312.42(e)
- 5Require FDA's written basis for the hold, including the specific information that served as the basis for it21 U.S.C. 355(i)(3)
Common mistakes
Filing a partial response to start the clock
the 30-day clock runs from receipt of the request and the complete response. A package missing one requested analysis does not start it, and the team loses a full review cycle discovering that.
Treating the pre-hold call as a formality
FDA tries to resolve the matter before issuing the order unless subjects face immediate and serious risk. That call is often the last point at which a protocol amendment avoids the hold entirely, and sponsors routinely staff it with people who cannot commit to a change.
Resuming dosing once the response is submitted
an investigation may only resume after FDA has notified the sponsor that it may proceed. Submission is not clearance. Dosing between the filing and that notice violates the order and becomes a finding in every subsequent inspection of the site.
When This Matters
- FDA put the Phase 1 dose escalation on partial clinical hold pending additional nonclinical toxicology.
- We are not dosing again until the hold is lifted in writing, complete response or not.
- The 30-day clock only starts when they receive a complete response, so a partial filing buys us nothing.
Frequently Asked Questions
FDA imposes a clinical hold when subjects face unreasonable and significant risk of illness or injury, investigators are unqualified, the investigator brochure is misleading or materially incomplete, or the IND lacks sufficient information under 21 CFR 312.23 to assess risk. For Phase 2 or 3, a protocol clearly deficient in design is an additional ground.
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