On August 22, 2025, FDA suspended the biologics license for Ixchiq, one of only two marketed chikungunya vaccines. The decision to suspend comes only a few weeks after FDA approved a Safety Labeling Change supplemental biologics license application for the vaccine product, due in part to subsequent VAERS reports of “chikungunya-like illness” in relatively healthy individuals under the age of 65.
FDA has expanded and accelerated its use of medical product withdrawal authorities over the last several years, but the agency’s use of its suspension authority, including in connection with a proposed withdrawal, to date has been rare. This shift may signal a new willingness from FDA to exercise greater and more liberal use of this authority, which in turn could emerge as a powerful tactic going forward.
While recent attention has focused on FDA’s application of its drug and biologic approval standard, equal focus should be paid to the other end of the spectrum: product withdrawal and FDA processes and standards around those determinations.
FDA Suspension Authority
The Federal Food Drug and Cosmetic Act (FFDCA) and Public Health Service Act (PHSA) both reference authority to suspend a granted marketing authorization for approved drug and biologic products, respectively. For example, 21 USC § 355(e) provides that “if the Secretary . . . finds that there is an imminent hazard to the public health, he may suspend the approval of such application immediately.”
As is often the case, the corresponding, and less-detailed, PHSA statutory language differs, even if FDA may take a similar regulatory approach in practice. On issuing the Ixchiq suspension, for example, FDA informed the BLA holder that it “no longer holds an unsuspended license for [the] vaccine and that unless and until otherwise notified, introduction or delivery for introduction into interstate commerce of such production is a violation of section 351(a) of the Public Health Service Act.” In other words, while FDA may in parallel seek to withdraw approval of a drug or biologic product, a suspension constitutes an immediate, if not necessarily permanent, revocation of a sponsor’s authority to market the product.
While the suspension authority set forth in the FFDCA describes an “opportunity for an expedited hearing” regarding the suspension, drawing some parallels to FDA-mandated product withdrawals, without a suspension in place a drug or biologic subject to proposed withdrawal proceedings from FDA may continue to be marketed while those proceedings are underway. (FDA’s suspension-related regulations for biologics in 21 CFR § 601.6 do not directly provide for hearings, but they are referenced in the related license-revocation provisions of 21 CFR § 601.5.)
Until this most recent action, FDA’s actions surrounding proposed withdrawals have not included concurrent suspension of marketing authority.
Supporting its decision, FDA released a memorandum related to the suspension including an “IXCHIQ safety signal timeline” spanning from April 15, 2025 to August 21, 2025. Notably, as documented in the memorandum—and emphasizing the speed with which FDA employed this statutory tool—FDA’s Center for Biologics Evaluation and Research (CBER) suspended the biologics license only one day after the manufacturer “did not indicate intent to voluntarily suspend distribution of the vaccine.”
CBER Director Dr. Vinayak Prasad explained that his decision to suspend was based on his reasonable belief that there is a ground for revocation of the underlying biologics license, i.e., that the product is not safe for all of its intended uses and by reason thereof there is a danger to health. CBER also noted that it intends to seek full withdrawal of the approval of the BLA using the expedited procedures available for products approved under FDA’s Accelerated Approval Program.
While formal withdrawal contains procedural safeguards that provide for orderly and often step-wise market impact, by contrast FDA’s suspension practice, as demonstrated here, results in near-immediate removal of a marketed product. While marketing approval technically remains intact, suspension can leave a company suddenly and unexpectedly scrambling to regain market access and reassure investors—potentially giving the agency formidable negotiation leverage to procure voluntary compliance.
On the other hand, the draconian and sudden impact of these historically seldom-used procedures may be ripe for challenge, both because the stakes are high and because suspension has not been challenged post-Chevron. Requisite intermediate determinations for suspension or decisions to forgo or abridge hearing procedures, for example, may draw arbitrary-and-capricious challenges from manufacturers wanting to keep their product on the market.
A Recent Challenge and Potential Counterweight: Vanda v. FDA
A recent DC Circuit case may invite such challenges, which saw the court overturn FDA’s denial of a sponsor’s request for a hearing based on its administrative summary judgment authority. While that case involved FDA’s refusal to initially approve an application, FDA-administered hearing processes apply in both contexts.
The court’s decision in Vanda did not eliminate FDA’s oft-used administrative summary judgment procedures, however, this opinion—finding disputed questions of fact related to FDA’s refusal to approve the underlying NDA—may limit when the agency can bypass drawn-out proceedings, even if statutory authority may be available to do so. Limiting FDA’s ability to apply summary judgment in its administrative proceedings generally, the decision may dampen FDA’s enthusiasm to undertake resource-intensive administrative hearings, including in the context of suspensions and withdrawals.
Looking Ahead
FDA has demonstrated a new willingness to use nontraditional means to achieve its policy goals in the context of proposed product withdrawals, including suspension and informal negotiation. Will we see FDA target more products via suspension, including in other product categories? If so, we would expect manufacturers to challenge these suspensions, and the DC Circuit has demonstrated that it will meaningfully police FDA’s compliance with its procedures based on a factual analysis of the record.
Morgan Lewis’s FDA regulatory and administrative law practices are actively staying abreast of this arena as it continues to evolve and impact marketed therapeutics.