HETLIOZ Drug Patent Profile

When do Hetlioz patents expire, and when can generic versions of Hetlioz launch?

Hetlioz is a drug marketed by Vanda Pharms Inc and is included in two NDAs. There are thirty-three patents protecting this drug and one Paragraph IV challenge.

This drug has two hundred and fifteen patent family members in twenty-four countries.

The generic ingredient in HETLIOZ is tasimelteon. There are three drug master file entries for this compound. Four suppliers are listed for this compound. Additional details are available on the tasimelteon profile page.

DrugPatentWatch^® Litigation and Generic Entry Outlook for Hetlioz

A generic version of HETLIOZ was approved as tasimelteon by TEVA PHARMS USA INC on December 12^th, 2022.

Summary for HETLIOZ

International Patents:	215
US Patents:	31
Applicants:	1
NDAs:	2
Finished Product Suppliers / Packagers:	1
Raw Ingredient (Bulk) Api Vendors:	58
Clinical Trials:	2
Patent Applications:	336
Drug Prices:	Drug price information for HETLIOZ
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for HETLIOZ
What excipients (inactive ingredients) are in HETLIOZ?	HETLIOZ excipients list
DailyMed Link:	HETLIOZ at DailyMed

See drug prices for HETLIOZ

Recent Clinical Trials for HETLIOZ

Identify potential brand extensions & 505(b)(2) entrants

Sponsor	Phase
Vanda Pharmaceuticals	Phase 1
Vanda Pharmaceuticals	Phase 4

See all HETLIOZ clinical trials

Pharmacology for HETLIOZ

Drug Class	Melatonin Receptor Agonist
Mechanism of Action	Melatonin Receptor Agonists

Paragraph IV (Patent) Challenges for HETLIOZ

Tradename	Dosage	Ingredient	Strength	NDA	ANDAs Submitted	Submissiondate
HETLIOZ	Capsules	tasimelteon	20 mg	205677	3	2018-01-31

US Patents and Regulatory Information for HETLIOZ

HETLIOZ is protected by forty-eight US patents and one FDA Regulatory Exclusivity.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Vanda Pharms Inc	HETLIOZ LQ	tasimelteon	SUSPENSION;ORAL	214517-001	Dec 1, 2020		RX	Yes	Yes	10,829,465		Y	Y
Vanda Pharms Inc	HETLIOZ	tasimelteon	CAPSULE;ORAL	205677-001	Jan 31, 2014	AB	RX	Yes	Yes	11,285,129
Vanda Pharms Inc	HETLIOZ	tasimelteon	CAPSULE;ORAL	205677-001	Jan 31, 2014	AB	RX	Yes	Yes
Vanda Pharms Inc	HETLIOZ LQ	tasimelteon	SUSPENSION;ORAL	214517-001	Dec 1, 2020		RX	Yes	Yes	10,610,511

Expired US Patents for HETLIOZ

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Vanda Pharms Inc	HETLIOZ	tasimelteon	CAPSULE;ORAL	205677-001	Jan 31, 2014	5,856,529

EU/EMA Drug Approvals for HETLIOZ

Company	Drugname	Inn	Product Number / Indication	Status	Generic	Biosimilar	Orphan	Marketing Authorisation	Marketing Refusal
Vanda Pharmaceuticals Netherlands B.V.	Hetlioz	tasimelteon	EMEA/H/C/003870Hetlioz is indicated for the treatment of Non-24-Hour Sleep-Wake Disorder (Non-24) in totally blind adults.,	Authorised	no	no	yes	2015-07-03

International Patents for HETLIOZ

When does loss-of-exclusivity occur for HETLIOZ?

Based on analysis by DrugPatentWatch, the following patents block generic entry in the countries listed below:

European Patent Office

Japan

Generics may enter earlier, or later, based on new patent filings, patent extensions, patent invalidation, early generic licensing, generic entry preferences, and other factors.

See the table below for additional patents covering HETLIOZ around the world.

Country	Patent Number	Title	Estimated Expiration
European Patent Office	3105212	TASIMELTÉON DE QUALITÉ PHARMACEUTIQUE, HAUTEMENT PURIFIÉ (HIGHLY PURIFIED PHARMACEUTICAL GRADE TASIMELTEON)
European Patent Office	3470405	TASIMELTEON DE QUALITÉ PHARMACEUTIQUE HAUTEMENT PURIFIÉE (HIGHLY PURIFIED PHARMACEUTICAL GRADE TASIMELTEON)
European Patent Office	4223747	TASIMELTEON DE QUALITÉ PHARMACEUTIQUE HAUTEMENT PURIFIÉ (HIGHLY PURIFIED PHARMACEUTICAL GRADE TASIMELTEON)
Japan	2017506642	高純度医薬品等級タシメルテオン

HETLIOZ Market Dynamics and Financial Trajectory (Tasimelteon): Demand, Pricing, Exclusivity, and Competitive Risks

Last updated: July 22, 2026

HETLIOZ (tasimelteon) is a niche chronobiology product with constrained patient pool in non-24-hour sleep-wake disorder (N24SWD) and a growth profile tied to (1) diagnosis rates and (2) payer access. Financial trajectory is shaped by limited label scope, specialty pharmacy distribution, and competitive headwinds from alternative off-label melatonin strategies and, in segments, other branded sleep agents. Patent and exclusivity timelines constrain near-term generic or biosimilar competition, but market share can still erode from formulary dynamics and prescribing behavior.

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What is the market size for HETLIOZ (tasimelteon) and how fast is it growing?

Answer: HETLIOZ addresses N24SWD, predominantly in individuals with blindness-related circadian rhythm disorders and, to a lesser extent, other patients with entrainment failure. The addressable market is small versus mainstream CNS therapies, so revenue growth tends to track specialty access, patient identification, and persistence rather than broad primary-care adoption.

Key demand drivers

• Diagnosis and referral flow: Uptake depends on clinician recognition of N24SWD and correct circadian assessment. Many patients experience delayed diagnosis, which caps early peak sales.
• Payer approvals and utilization management: Prior authorization and step edits can slow new starts and reduce persistence.
• Specialty distribution and adherence: Daily dosing plus high “therapy patience” requirements influences discontinuation and repeat prescriptions.

Key demand inhibitors

• Small, well-defined label population: N24SWD is limited compared with broader insomnia markets.
• Treatment switching and off-label alternatives: In practice, some prescribers use melatonin and behavioral sleep interventions first, especially where payer coverage is uncertain.
• Chronic therapy churn: Circadian disorders can involve long periods of instability; patients can stop if perceived benefit is delayed.

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How do payer mix, specialty pharmacy access, and pricing affect HETLIOZ revenue?

Answer: HETLIOZ’s revenue is most sensitive to payer mix (commercial vs Medicare vs Medicaid), net price realization after rebates, and formulary placement in specialty channels. Small absolute unit volumes make percentage shifts in rebates and access especially impactful.

Commercial access mechanics

• Formulary tier placement: If HETLIOZ is restricted to specialty tiers or excluded from some regional formularies, new starts fall.
• Prior authorization criteria: Payers often require documentation consistent with N24SWD diagnosis and severity.
• Reimbursement leverage in rare disease channels: Even in “rare” settings, larger integrated payers can drive meaningful rebate pressure.

Net-to-gross risks

• Specialty CNS products can face rebate compression when competing branded therapies or therapeutics with similar adherence claims gain negotiated coverage.
• If competitors secure preferred status for circadian indications, HETLIOZ pricing leverage declines despite stable WAC.

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How does HETLIOZ perform financially: revenue trajectory, margins, and selling intensity?

Answer: As a niche specialty branded drug, HETLIOZ revenue trajectory typically shows steady-but-modest growth in peak years and mid-single to low-double digit growth in periods of access gains, followed by flattening as formulary saturation occurs. Margin structure depends on distribution channel economics, specialty pharmacy fees, and rebate rate changes rather than on scale manufacturing alone.

What to look for in financial statements and KPIs

• Net sales vs gross-to-net: Rebates and returns can dominate apparent growth.
• Script volume and new starts: Units tend to move less than revenue if net price or rebate rate changes.
• Specialty pharmacy channel penetration: Direct and specialty wholesaler ordering patterns indicate momentum.

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When does HETLIOZ lose exclusivity, and how does that affect generic entry risk?

Answer: Generic entry timing is governed by patent expiry and regulatory exclusivity periods tied to the NDA and any supplemental exclusivities. Market impact typically materializes first in channel negotiation pressure and then in unit share loss after actual generic launch.

Exclusivity and patent landscape basics that drive timelines

• Orange Book-listed patents determine first wave of potential Paragraph IV filings.
• Regulatory exclusivity (NME/3-year/7-year depending on the approval history) can delay approval even if patents expire.
• Loss of exclusivity does not automatically equal immediate generic launch because generic sponsors still need bioequivalence package strength, manufacturing readiness, and labeling claim compatibility.

Generic entry channels

• ANDA Paragraph IV challenges can accelerate approval date if the court or settlement changes outcome.
• Authorized generics can appear earlier than “at-risk” generics if settlements drive launch.

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What patents protect HETLIOZ (tasimelteon), and which are most relevant to market exclusivity?

Answer: The relevant patent set is the Orange Book patent family tied to tasimelteon drug substance and any formulation, method-of-use, or crystalline/solid-state patents. The most market-relevant patents are those with the latest expiry and any patents that cover the commercial dosage form and use that fits the FDA-approved N24SWD indication.

Patent estate structure

• Drug substance patents: Often cover the chemical entities or intermediates.
• Formulation patents: Cover specific composition, dosage form, or release characteristics.
• Method-of-use patents: Cover treatment and patient selection for N24SWD.

How to interpret “most relevant” in business terms

• The latest-expiring listed patent(s) usually govern the earliest generic launch date.
• Method-of-use patents can create a “carve-out” risk where generics may still launch but with labeling constraints, depending on litigation and settlement.

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What is the Orange Book status of HETLIOZ (tasimelteon) and how many patents are listed?

Answer: Orange Book status is determined by the set of patents listed for the approved NDA, including active and expired entries and any those with the latest expiration. That count sets the breadth of potential litigation and the degree of “multi-barrier” protection.

Practical impact

• More listed patents increases litigation surface area, raises settlement leverage, and can delay entry.
• Fewer listed patents often means one or two blockers dominate the timeline.

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Are there any Paragraph IV filings or patent litigation affecting HETLIOZ?

Answer: Patent litigation risk is assessed by tracking Paragraph IV certifications (when an ANDA challenges listed patents), litigation dockets, and settlement agreements that shift launch dates.

Why litigation matters even for a small market

• In small markets, a single 6- to 12-month schedule change can determine whether a generic sponsor recoups fixed development and commercialization costs.
• Settlements frequently include “agreed-upon” launch dates or non-infringement conditions.

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What biosimilar or biologic competition exists for HETLIOZ?

Answer: HETLIOZ is a small-molecule product. Biosimilar competition is not applicable.

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What formulations are protected for HETLIOZ, and do formulation patents block generic substitution?

Answer: Formulation patents can prevent approval of a generic if the protected aspects are required for bioequivalence or if the protected release or composition is tied to the approved product. If the formulation patents expire later than substance or method patents, they often become the final barrier.

Dosage form considerations

• Generic substitution depends on the exact dose strength, dosage form, and whether equivalence is straightforward under regulatory standards.
• Formulation-dependent barriers often reduce at-risk launch likelihood.

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How does HETLIOZ compare with melatonin strategies and other insomnia or circadian therapies?

Answer: The market competition for HETLIOZ comes less from direct “same indication, same mechanism” brands and more from (1) off-label melatonin/behavioral approaches and (2) payer-preferred insomnia agents where clinicians treat broader insomnia rather than strict N24SWD.

Competitive comparison axes

• Indication specificity: HETLIOZ’s label specificity is a competitive moat but also a limitation.
• Time-to-entrainment and perceived efficacy: Patient and clinician expectations influence switching.
• Access and prior authorization friction: Even when efficacy is accepted, coverage determines persistence.

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Which companies are challenging HETLIOZ, and what launch scenarios are most likely?

Answer: Generic challenger names and launch scenarios depend on whether ANDA Paragraph IV certifications are filed against Orange Book patents for tasimelteon. The most likely launch scenarios are:

• Full launch on earliest date after latest relevant patent expiry and regulatory exclusivity clearance.
• Design-around or labeling carve-out if the sponsor avoids method-of-use infringement or if settlements modify labeling.

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What is the revenue exposure of HETLIOZ to exclusivity changes, payer shifts, and competitive entry?

Answer: Revenue exposure is concentrated in (1) net price realization after rebate renegotiation and (2) any schedule changes in the exclusivity-to-generic corridor that could trigger formulary switching. Because the market is relatively small, unit volume shocks can move revenue quickly once payer coverage changes.

Exposure map (business framing)

• High sensitivity: net-to-gross rebate changes; preferred formulary transitions.
• Medium sensitivity: changes in diagnosis rates and clinician adoption.
• Low to medium sensitivity: general market economic shifts; CNS category macro trends.

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Key timeline: what matters from now for HETLIOZ revenue

Answer: The timeline that matters is the gap between (1) Orange Book patent expiries and (2) regulatory exclusivity end, since it determines whether generic threats arrive via Paragraph IV at-risk entry or later “authorized/settled” launch paths.

Timeline driver	Why it moves revenue	What to monitor
Latest relevant patent expiry	Earliest generic approval window	Orange Book latest expiration dates and patent status
Regulatory exclusivity end	Delay to ANDA approval even if patents expire	NDA exclusivity codes and any amendments
Litigation/settlement outcomes	Launch-date shift	Court outcomes; consent judgments; settlement press releases
Payer formulary changes	Units and persistence	Prior authorization updates; formulary tier moves
Competitor contracting	Net price compression	PBM contracting cycles and drug-class preferences

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Key Takeaways

• HETLIOZ’s growth is constrained by the small addressable population for N24SWD and is driven by diagnosis rates, specialty access, and payer coverage rather than broad insomnia-category expansion.
• Financial trajectory depends more on net price realization and rebates than on raw pricing, given specialty economics and limited volume.
• Near-term competitive risk is primarily patent- and payer-driven, with generic entry timing anchored to Orange Book patent expiry and any Paragraph IV litigation or settlements.
• The competitive landscape is defined by treatment alternatives (melatonin and behavioral approaches) and payer access friction, not biosimilar competition.

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FAQs

1) What factors most affect HETLIOZ demand in non-24-hour sleep-wake disorder?
Diagnosis speed, specialist referral patterns, payer authorization criteria, and patient persistence once therapy begins.

2) How does net price (rebates and discounts) typically influence HETLIOZ net sales?
Net-to-gross swings can dominate revenue growth in niche markets because unit volumes are limited.

3) What is the main regulatory pathway risk for generic HETLIOZ?
ANDA approval timing determined by Orange Book patent expiry status and regulatory exclusivity, plus any litigation around challenged patents.

4) Does HETLIOZ have formulation or method-of-use barriers that delay generics?
Formulation and method-of-use patents can constrain generic design-around or labeling, affecting launch timing and uptake.

5) What payer actions are most likely to change HETLIOZ utilization quickly?
Prior authorization tightening or loosening, formulary tier changes, and PBM preference contracts.

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References (APA)

1. U.S. Food and Drug Administration. (n.d.). Drugs@FDA: HETLIOZ (tasimelteon). FDA.
2. U.S. Food and Drug Administration. (n.d.). Orange Book: Approved Drug Products with Therapeutic Equivalence Evaluations (tasimelteon). FDA.
3. Public court records and dockets for Paragraph IV tasimelteon litigation (if applicable).

DrugChatter Q&A for HETLIOZ

Why is hetlioz so expensive?