Following the reasoning in the court’s decision, Warning Letters may become reviewable agency actions when an entity receives an adverse citizen petition decision after challenging a letter.
On January 29, 2026, the District Court for the Southern District of Florida sided with plaintiff Hybrid Pharma LLC, determining that the U.S. Food & Drug Administration’s (FDA) denial of its citizen petition challenging two Warning Letters issued by the agency constituted “final agency action” ripe for judicial review under the Administrative Procedures Act (APA).
Background
In 2025, plaintiff Hybrid Pharma—a registered “outsourcing facility” that specializes in compounding and dispensing pharmaceuticals—filed a complaint against the FDA under the APA, challenging the agency’s decision to issue two Warning Letters after separate inspections of its facility in 2018 and 2022 for failure to meet necessary conditions under section 503B of the Food Drug & Cosmetics Act.
The Warning Letters, Hybrid Pharma alleged, caused the company to incur a substantial loss of business and revenue, including the indefinite pause of a clinical trial with Yale University, among other losses.[1] Hybrid Pharma also alleged that the Warning Letters, which are published on the FDA’s website and available to the public, caused them serious reputational and economic harm.
Accordingly, the company filed a citizen petition to the FDA, requesting that the agency rescind both Warning Letters on the basis that the agency had failed to follow its own policies and procedures, as set forth in the Regulatory Procedures Manual, when it issued the letters against the company.[2] FDA denied Hybrid Pharma’s citizen petition on September 10, 2024.
Challenge to Agency Action
In Hybrid Pharma LLC v. FDA, No. 24-62413-CIV-DAMIAN (S.D. Fla. Jan. 29, 2026), Hybrid Pharma challenged FDA’s decision to issue the Warning Letters and sought declaratory and injunctive relief—the recission of the Warning Letters at issue as arbitrary and capricious. FDA, filed a motion to dismiss, arguing, as relevant here, that Hybrid Pharma had not stated a plausible claim for relief under the APA because Warning Letters are not a “final agency action” within the meaning of the APA’s judicial review provision.
The APA authorizes judicial review of agency actions only when the action is a “final” agency action, and the case is brought by a person suffering a legal wrong due to that agency action. The United States Supreme Court has held that the APA:
[L]imits the agency actions that are subject to judicial review. Unless another statute makes the agency’s action reviewable … judicial review is available only for "final agency action." In most cases, then, a plaintiff can only challenge an action that "mark[s] the consummation of the agency's decision making process" and is "one by which rights or obligations have been determined, or from which legal consequences will flow." [Internal citations omitted.]
Courts have long held that companies cannot typically sue the FDA to challenge the issuance of Warning Letters because the letters themselves do not rise to the level of a final agency action. Hybrid Pharma, however, asserted that it requested a review of the agency’s denial of its citizen petition that challenged the issuance of the Warning Letters, not the issuance of the Warning Letters themselves. The agency’s response to the citizen petition, they argued, is reviewable.
The FDA contended that the APA claim was nonetheless directed at the issuance of the Warning Letters and that the decision to issue a Warning Letter is not made reviewable under the APA just because the agency responded to a citizen petition. Further, the FDA noted that Hybrid Pharma’s complaint attacked the citizen petition decision but did not allege any wrongful or unlawful conduct on the agency’s part in issuing its decision. Rather, the complaint, the FDA argued, focused on its allegations that the Warning Letters were improperly issued.
The court, however, agreed with Hybrid Pharma and determined that the company could seek judicial review of the Warning Letters by way of the FDA’s response to the citizen petition because the citizen petition is a final agency action, and the warning letters were the initial reason that the company initiated the petitions in the first place. Thus, the court denied the FDA’s motion to dismiss and stated that Hybrid Pharma had sufficiently alleged a cognizable claim under the APA.
Takeaways
Following the reasoning in the court’s decision, Warning Letters may become reviewable agency actions when an entity receives an adverse citizen petition decision after challenging a letter. Thus, the court’s opinion in the Hybrid Pharma case signals a potential path for FDA-regulated entities to challenge Warning Letters, albeit under limited circumstances. Regulated entities would need to consider the potential delays and resources involved in submitting—and getting FDA to reply to—a citizens petition in the first place before it could turn to the advantages of challenging a Warning Letter in court on that basis.
Further, this court’s decision is unique and future litigation could shed light on the limited application of the holdings in Hybrid Pharma.
While the court’s limited precedent applies in the Southern District of Florida, other courts may not agree with the opinion’s underlying findings. Other courts may also address issues that the Florida court did not opine on. The Hybrid Pharma court, for example, notably did not address the exhaustion of remedies requirement, or opine on what would happen if the plaintiff challenged the citizen petition process and denial itself, rather than the underlying Warning Letters.
For More Information
If you have any questions about this Alert, please contact Frederick R. Ball, Annie Blackman, any of the attorneys in our Life Sciences and Medical Technologies Industry Group or the attorney in the firm with whom you are regularly in contact.
Notes
[1] FDA issues Warning Letters to notify entities of when it identifies what it believes to be significant violations of federal requirements, including “poor manufacturing practices, problems with claims for what a product can do, or incorrect directions for use.” FDA indicates that the purpose of the letters is to provide companies with an opportunity to address FDA’s concerns within a certain timeframe to avoid further action by the agency.
[2] Citizen petitions are avenues for individuals, regulated industry stakeholders or consumer groups to petition FDA to issue, amend or revoke a regulation, or to take other administrative action.
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