Vanda Pharmaceuticals (VNDA) wins FDA’s first formal drug approval hearing in 40 years as Hetlioz jet lag battle enters new phase

Vanda Pharmaceuticals Inc. (Nasdaq: VNDA) has secured one of the most procedurally significant regulatory victories in recent U.S. pharmaceutical history, with the Food and Drug Administration agreeing to convene a formal evidentiary public hearing to review its proposed refusal to approve the supplemental new drug application for Hetlioz (tasimelteon) in jet lag disorder. The FDA confirmed the decision in a letter from the Office of the Commissioner dated March 2, 2026, with the hearing to proceed under 21 CFR Part 12, a regulatory pathway that has not been invoked in a drug approval context for more than four decades. For a company whose core sleep portfolio is under meaningful revenue pressure, the hearing represents more than a procedural win: it reopens a market opportunity the company has been fighting to access since 2018, and it does so in a way that places the evidentiary burden directly on the FDA to justify its proposed rejection. VNDA shares traded at $8.49 on March 4, 2026, up 3.6% on the day, against a 52-week range of $3.81 to $9.60, reflecting investor recognition of the development’s strategic weight.

What makes a 21 CFR Part 12 hearing historically rare and why does it matter for Vanda’s regulatory position?

The formal evidentiary hearing mechanism under 21 CFR Part 12 is not simply a procedural escalation. It is a full adjudicatory process in which a presiding officer weighs evidence, hears arguments, and issues an initial decision that then travels up the administrative chain before any final determination is made. The FDA has not granted such a hearing in a drug approval dispute in over 40 years, which itself speaks to how unusual it is for a proposed drug refusal to generate sufficient legal and scientific weight to warrant the process. Granting the hearing means the FDA, under the Office of the Commissioner led by Dr. Marty Makary, has accepted that the evidentiary and regulatory questions at stake here are not resolvable through the standard administrative back-and-forth that has characterized this case for seven years.

That context matters. The Vanda Pharmaceuticals case is not simply about jet lag. It has become a test of how the FDA handles clinical evidence that falls outside its preferred trial design paradigms. The D.C. Circuit’s August 2025 ruling in Vanda Pharmaceuticals Inc. v. FDA, case no. 24-1049, was unusually direct in its criticism, describing Vanda’s evidence as specific, reasoned, and rooted in evidence while characterizing the FDA’s earlier review as cursory. Courts are rarely that explicit when reviewing agency scientific determinations, and the strength of that language has shaped every subsequent regulatory step.

How did the seven-year Hetlioz jet lag dispute reach the point of a formal Part 12 hearing in 2026?

Vanda Pharmaceuticals submitted its supplemental new drug application for Hetlioz in jet lag disorder in October 2018. The FDA rejected it in 2019, citing concerns about whether Vanda’s phase-advance trial methodology, which simulated jet lag by shifting participants’ bedtimes by five and eight hours rather than putting them on actual transcontinental flights, was sufficiently analogous to real-world travel conditions. The FDA argued that genuine jet travel introduces additional physiological variables, including reduced ambient oxygen pressure, physical confinement, altered lighting cycles, and noise exposure, that the trial protocols did not replicate.

Vanda contested that interpretation and spent the following years attempting to secure a hearing through administrative channels, ultimately suing the FDA when those requests were denied. A federal district court ruled in Vanda’s favor in January 2024, ordering the agency to either resolve the application or grant a hearing. The FDA responded with another rejection rather than a hearing. Vanda appealed, and the D.C. Circuit’s August 2025 ruling set aside the second refusal and remanded the application. Under the October 2025 collaborative framework agreement that followed, the FDA committed to an expedited re-review by January 7, 2026, including consideration of narrowed sleep-focused indications.

That re-review produced a third refusal, issued January 8, 2026. While acknowledging Hetlioz’s positive efficacy in clinical trials, the agency maintained that the trial protocols remained insufficiently analogous to actual jet travel. Vanda described the decision as not fully reflecting the collaborative spirit of the agreement. With the application still under D.C. Circuit remand, the FDA was now obligated to either approve the drug or formally commence a hearing. It has chosen the hearing.

What are the core scientific and regulatory arguments that will determine the outcome of the Hetlioz hearing?

The central evidentiary dispute is methodological. Vanda’s Phase II and Phase III clinical trials used phase-advance protocols, shifting participants’ sleep timing to simulate eastward transmeridian travel. The trials, completed in 2017 and 2018, produced statistically significant improvements on primary endpoints, and that efficacy signal has not been seriously contested by the FDA. The agency’s objection is not that Hetlioz does not work in the conditions studied but that the conditions studied are not the same as flying from New York to Tokyo.

Vanda’s counterargument, reinforced by the D.C. Circuit’s framing, is that the circadian disruption mechanism underlying jet lag is the same whether it results from transmeridian travel or controlled phase-advance manipulation in a clinical setting. The company has also pursued narrowed labeling approaches, focusing on the sleep disruption component of jet lag rather than the full syndrome, which the FDA agreed to consider during the January re-review but ultimately still rejected. At the hearing, Vanda will have the opportunity to present this case before a neutral presiding officer with full evidentiary formality, rather than through the letter-and-response process that has characterized all previous interactions.

The regulatory stakes extend beyond Hetlioz. The FDA’s 21 CFR Part 12 standard requires that refusals to approve be based on substantial evidence. If Vanda can demonstrate through the hearing process that the FDA’s phase-analogy objection lacks substantial evidentiary foundation, that finding would bind the final decision, limiting the agency’s ability to maintain the rejection without stronger scientific justification.

How does the jet lag market opportunity compare to Hetlioz’s current commercial trajectory and what does approval unlock?

The commercial context for this regulatory battle has become more urgent as Hetlioz’s existing revenue base has contracted. The drug generated $173 million in peak annual sales in 2021, driven by its Non-24-Hour Sleep-Wake Disorder indication and its approval for nighttime sleep disturbances in Smith-Magenis syndrome. By 2024 that figure had fallen to $77 million, with only $55 million through the first three quarters of 2025. The combination of a niche patient base for the approved indications, patent pressure, and limited upward pricing capacity has put the drug on a structural decline curve.

Jet lag disorder represents a qualitatively different commercial profile. Unlike Non-24-Hour Sleep-Wake Disorder, which affects a small population of blind individuals with disrupted circadian rhythms, jet lag disorder is experienced by tens of millions of travelers annually across business, athletic, military, and consumer segments. There is currently no FDA-approved pharmaceutical treatment for the condition. A successful approval would give Hetlioz a direct-to-consumer and occupational health market with no existing competition from approved products, and a pricing environment unconstrained by the narrow orphan drug context of its current labels. For a company with a 94% gross margin on product revenue but a negative EBITDA of approximately $139 million, that revenue diversification would be material.

Vanda’s other recent regulatory actions provide additional pipeline context. The FDA approved Bysanti (milsaperidone) for bipolar I disorder and schizophrenia in February 2026, and the agency accepted a Biologics License Application for imsidolimab in generalized pustular psoriasis the same month. These are meaningful pipeline advances, but neither carries the revenue potential of an approved jet lag indication given the scale of the addressable market.

What does the FDA’s decision to grant this hearing signal about the agency’s posture under current leadership?

The FDA’s willingness to grant a formal Part 12 hearing is notable not only for its rarity but for its timing. Commissioner Makary, who took office in 2025, has signaled a broader interest in regulatory transparency and process reform. Vanda’s CEO Mihael Polymeropoulos characterized the hearing as a significant reform step by the FDA toward greater transparency, and that framing is not entirely promotional. An agency that had previously declined to grant any hearing in this case, despite a federal district court ordering it to do so, is now voluntarily convening one. The shift in posture under new leadership, combined with the D.C. Circuit’s clear directive, suggests the FDA is choosing to resolve this through a defensible formal process rather than continuing to resist through administrative channels.

That choice has systemic implications. Other pharmaceutical companies watching this case will note that a sufficiently rigorous evidentiary record, backed by published peer-reviewed clinical data and pursued through litigation when necessary, can eventually force the agency into a formal adjudicatory process. The Vanda precedent does not guarantee success at the hearing stage, but it establishes that the Part 12 hearing mechanism is not a dead letter. Companies with strong evidentiary positions and the resources to sustain multi-year regulatory litigation now have a clearer template.

What are the execution risks and remaining uncertainties before a final approval decision on Hetlioz jet lag?

The hearing is a procedural gateway, not an approval. Once the presiding officer issues an initial decision under 21 CFR Section 12.120, that decision is subject to further administrative review before a final order is issued. The full timeline is uncertain, and the outcome remains genuinely contested on scientific grounds. Vanda will need to present a compelling case that its phase-advance methodology is legally and scientifically equivalent for the purposes of establishing efficacy in a broader jet lag indication. The FDA’s scientific staff will have the opportunity to rebut that case formally.

There is also regulatory complexity around labeling. Even if Vanda prevails at the hearing, the scope of the approved indication, whether it covers jet lag broadly or only specific sleep-disruption components of the syndrome, will significantly affect commercial viability. A narrow label covering only circadian-related sleep onset difficulties in travelers would be harder to market than a full jet lag disorder designation. Risk-management and post-marketing commitment requirements could also impose cost burdens on a company already operating at a loss.

On the financial side, Vanda reported Q4 2025 earnings per share of minus $2.39 against a consensus estimate of minus $0.97, a significant miss. Revenue through 2025 reflected the structural pressure on Hetlioz’s existing indications. While the balance sheet and gross margin profile provide operational runway, sustained litigation and regulatory engagement at this level is not costless, and the company’s burn rate bears watching through the hearing process, which could extend well into 2026 or beyond.

Key takeaways: what the FDA Part 12 Hetlioz hearing means for Vanda, competitors, and the industry

• The FDA’s decision to grant a 21 CFR Part 12 hearing is the first such drug approval hearing in over 40 years, signaling that the agency, under Commissioner Makary, is adopting a more transparent adjudicatory posture on disputed applications.
• The hearing does not guarantee approval. It opens a formal evidentiary process in which Vanda must demonstrate that its phase-advance trial methodology meets the substantial evidence standard for jet lag disorder.
• The central scientific dispute, whether a controlled phase-advance study is sufficiently analogous to real transmeridian travel, is genuinely unresolved. The presiding officer’s initial decision will set a precedent for how the FDA evaluates surrogate endpoints in circadian disorders.
• Commercial stakes are high. Jet lag disorder has no FDA-approved treatment, and the addressable market across business travelers, military personnel, and athletes is orders of magnitude larger than Hetlioz’s current orphan-drug patient base.
• Hetlioz revenue has declined from a $173 million peak in 2021 to $77 million in 2024. A jet lag approval would provide the revenue diversification Vanda needs to move toward profitability, particularly given the drug’s 94% gross margin.
• VNDA shares, trading at $8.49 against a 52-week low of $3.81 and a high of $9.60, are pricing in meaningful but not overwhelming approval probability. Analyst consensus targets average $13.63, suggesting significant upside if the hearing produces a favorable outcome.
• For the pharmaceutical industry broadly, the Vanda precedent demonstrates that the Part 12 hearing mechanism can be invoked after sustained litigation, giving other companies with strong evidentiary records a new strategic tool against FDA rejections they believe lack substantial basis.
• Execution risk remains material. The hearing timeline is uncertain, the labeling scope if approved will determine commercial viability, and Vanda’s financial losses make protracted proceedings a cost burden. The company’s Q4 2025 EPS miss of $1.42 against consensus underscores the financial pressure.
• The D.C. Circuit’s August 2025 language, describing Vanda’s evidence as specific, reasoned, and rooted in evidence while calling the FDA’s earlier review cursory, has placed the evidentiary burden squarely on the agency to justify its proposed refusal with greater analytical rigor than it has demonstrated to date.
• No date for the formal hearing has been announced. The process under 21 CFR Part 12 involves scheduled evidentiary sessions, written submissions, and a final administrative record before any initial decision is issued, suggesting the resolution timeline extends into late 2026 at the earliest.