HALAVEN Drug Patent Profile

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

Halaven is a drug marketed by Eisai Inc and is included in one NDA. There is one patent protecting this drug and one Paragraph IV challenge.

This drug has thirty-eight patent family members in fourteen countries.

The generic ingredient in HALAVEN is eribulin mesylate. Sixteen suppliers are listed for this compound. Additional details are available on the eribulin mesylate profile page.

DrugPatentWatch^® Litigation and Generic Entry Outlook for Halaven

A generic version of HALAVEN was approved as eribulin mesylate by GLAND on April 5^th, 2024.

Summary for HALAVEN

International Patents:	38
US Patents:	1
Applicants:	1
NDAs:	1
Finished Product Suppliers / Packagers:	2
Raw Ingredient (Bulk) Api Vendors:	43
Clinical Trials:	63
Patent Applications:	1,280
Drug Prices:	Drug price information for HALAVEN
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for HALAVEN
What excipients (inactive ingredients) are in HALAVEN?	HALAVEN excipients list
DailyMed Link:	HALAVEN at DailyMed

See drug prices for HALAVEN

Recent Clinical Trials for HALAVEN

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

Sponsor	Phase
Guangdong Provincial People's Hospital	Phase 2
First Affiliated Hospital, Sun Yat-Sen University	Phase 2
Sun Yat-sen University	Phase 2

See all HALAVEN clinical trials

Pharmacology for HALAVEN

Drug Class	Microtubule Inhibitor
Physiological Effect	Microtubule Inhibition

Paragraph IV (Patent) Challenges for HALAVEN

Tradename	Dosage	Ingredient	Strength	NDA	ANDAs Submitted	Submissiondate
HALAVEN	Injection	eribulin mesylate	1 mg/2 mL	201532	1	2019-12-20

US Patents and Regulatory Information for HALAVEN

HALAVEN is protected by one US patents and two FDA Regulatory Exclusivities.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Exclusivity Expiration
Eisai Inc	HALAVEN	eribulin mesylate	SOLUTION;INTRAVENOUS	201532-001	Nov 15, 2010	AP	RX	Yes	Yes					Y
Eisai Inc	HALAVEN	eribulin mesylate	SOLUTION;INTRAVENOUS	201532-001	Nov 15, 2010	AP	RX	Yes	Yes
Eisai Inc	HALAVEN	eribulin mesylate	SOLUTION;INTRAVENOUS	201532-001	Nov 15, 2010	AP	RX	Yes	Yes

Expired US Patents for HALAVEN

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	Patent No.	Patent Expiration
Eisai Inc	HALAVEN	eribulin mesylate	SOLUTION;INTRAVENOUS	201532-001	Nov 15, 2010
Eisai Inc	HALAVEN	eribulin mesylate	SOLUTION;INTRAVENOUS	201532-001	Nov 15, 2010
Eisai Inc	HALAVEN	eribulin mesylate	SOLUTION;INTRAVENOUS	201532-001	Nov 15, 2010

International Patents for HALAVEN

See the table below for patents covering HALAVEN around the world.

Country	Patent Number	Title	Estimated Expiration
Austria	502932
Australia	2003284242	METHODS AND COMPOSITIONS FOR USE IN TREATING CANCER
Australia	4573999	Macrocyclic analogs and methods of their use and preparation
Australia	762998
Brazil	9911326	Análogos macrocìclicos e métodos para seu uso e preparação
Canada	2335300	ANALOGUES MACROCYCLIQUES, LEURS PROCEDES D'UTILISATION ET DEPREPARATION (MACROCYCLIC ANALOGS AND METHODS OF THEIR USE AND PREPARATION)

Supplementary Protection Certificates for HALAVEN

Patent Number	Supplementary Protection Certificate	SPC Country	SPC Expiration	SPC Description
1087960	C300493	Netherlands		PRODUCT NAME: ERIBULIN, ALSMEDE FARMACEUTISCHE ZOUTEN ERVAN, IN HET BIJZONDER HET MESYLAAT; REGISTRATION NO/DATE: EU/1/11/678/001-002 20110317
1087960	91854	Luxembourg		PRODUCT NAME: ERIBULIN ET SES DERIVES PHARMACEUTIQUEMENT ACCEPTABLES (HALAVEN ); AUTHORISATION NUMBER AND DATE: EU/1/11/678/001-002, 17.03.2011
1087960	CA 2011 00022	Denmark
1087960	SPC026/2011	Ireland		SPC026/2011: 20111128, EXPIRES: 20240615
1087960	1190021-4	Sweden		PRODUCT NAME: ERIBULIN OCH FARMACEUTISKT ACCEPTABLA SALTER DAERAV, I SYNNERHET ERIBULINMESYLAT; REG:NO:/DATE: EG EU/1/11/678/001-002, 2011-03-17
1087960	11C0038	France		PRODUCT NAME: ERIBULINE, SES SELS PHARMACEUTIQUEMENT ACCEPTABLES, EN PARTICULIER MESYLATE D'ERIBULINE; REGISTRATION NO/DATE: EU/1/11/678/001 20110317

Halaven (eribulin) market dynamics and financial trajectory: exclusivity, competitive pressure, and revenue outlook

Last updated: July 22, 2026

Halaven (eribulin) remains a niche but durable oncology revenue contributor built on hepatocellular and breast cancer indications that have largely shifted to later-line use. Market dynamics are driven by (1) post-2019 breast cancer competitive substitution, (2) limited new patient expansion due to changing sequencing and payer scrutiny, and (3) ongoing risk that additional generic entry or erosion in select geographies can tighten pricing. Financial trajectory is typically characterized by a steady-to-declining revenue pattern once the initial launch wave and later-line share gains normalize, with growth most sensitive to U.S. and major ex-US hospital formularies and to continued uptake in liposarcoma line settings where alternatives are still constrained.

What patents protect Halaven (eribulin) and how do they shape generic and biosimilar risk?

Halaven is a small-molecule oncology drug (not a biologic), so the competitive threat is primarily generic chemical copies and authorized generics, not biosimilars. Patent protection controls the timing of generic entry in each jurisdiction through composition-of-matter coverage, formulation/process coverage, and method-of-use coverage (where applicable).

Which patent estate buckets matter for Halaven?

1. Composition-of-matter: covers eribulin and key chemical embodiments.
2. Formulation patents: covers drug product formats (e.g., injectable composition, solubilization approach, excipient systems, concentration).
3. Method-of-use patents: covers specific dosing regimens and line-of-therapy placements (if claimed).
4. Manufacturing/process patents: covers synthesis steps or purification controls.

What does this mean for market dynamics?

• If composition-of-matter patents are still active, generic entrants face full Paragraph IV-type and/or infringement risk unless they carve around non-infringing embodiments.
• If only formulation or method-of-use patents remain, generics can potentially enter by using a non-infringing formulation or by not practicing a patented regimen. That reduces the risk of total brand displacement but can still pressure pricing because payers can switch to the generic.

Patent-expiration timing as a demand variable

For late-line oncology products like Halaven, revenue is most sensitive to:

• the “runway” before key patent cliffs in major markets (U.S., EU5, Japan, and select Asia),
• whether regulators list the generic quickly after a patent loss (fast path to substitution),
• and whether the brand retains access through contracting and supply continuity.

When does Halaven lose exclusivity and what generic entry risks exist?

Exclusivity loss is evaluated on two overlapping planes: patent expiry and regulatory exclusivity mechanisms. For small molecules, exclusivity is usually less determinative than patent life, with the key practical drivers being Orange Book status and any FDA-led listing events.

What is the Orange Book status of Halaven?

Orange Book status governs generic entry risk in the U.S. The practical market outcome is determined by:

• which patents are listed for each NDA/product,
• whether any patents are listed for each dosage form and strength,
• and which patents expire first.

What generic entry risks exist for Halaven by market?

• U.S.: generic entry depends on Orange Book-listed patent expiry and any Hatch-Waxman litigation outcome. If Halaven’s remaining patents include method-of-use or formulation claims, a generic may face launch restrictions or be forced into “skinny” labeling strategies.
• EU: generic authorization timing is more strongly tied to the patent regime in each country and to whether patents remain enforceable at the national level.
• Japan/Canada: similar dynamics with active patent enforcement and local regulatory review timelines.

Market impact model used by payers and wholesalers

Even when patents expire, switching typically follows:

1. uptake in community sites after hospital formularies add generics,
2. price erosion driven by wholesaler rebates and contract tender cycles,
3. secondary pressure on brand inventory and tender pricing.

For oncology injectable products, supply chain continuity matters: if generic supply is constrained, the brand can retain a base share longer than patent math suggests.

How strong is the patent estate for Halaven compared with competing late-line breast cancer and liposarcoma drugs?

Halaven’s competitive set includes late-line options used after anthracycline and taxane exposure in breast cancer, and after standard first-line management in liposarcoma for certain settings. The brand’s patent strength shapes how long it can maintain contracting leverage before generic substitution and how much it can withstand competitor-led sequencing shifts.

Where brand strength tends to be concentrated

For older oncology small molecules:

• the biggest revenue tail usually persists where dosing schedules are embedded in clinical pathways and where prescriber familiarity plus payer coverage reduce friction,
• the biggest erosion comes from sequencing changes that shift patients earlier to other therapies or that narrow access in later-line settings.

Comparative market pressure drivers

Brand erosion for Halaven typically comes from three sources:

• Treatment-line substitution: competitors move into earlier lines, lowering late-line volume.
• Payer formulary narrowing: steeper prior-authorization controls for high-cost regimens.
• Price competition: once generic or authorized generic appears in any major market, branded pricing loses contracting leverage.

What formulations are protected by Halaven and does product form affect substitution?

Halaven is administered by injection; injectable oncology products often have fewer “consumer” switching points, but product-formulation details can be central for generic patent design-around.

Key formulation-driven barriers generics face

• Concentration and excipient system that affects stability and solubility
• Manufacturing process controlling impurities and particle characteristics
• Packaging and administration compatibility claims (where included)

Market outcome

• If formulation patents remain intact, generic entry can be delayed or can launch with constrained labeling.
• Even when generic approval occurs, payer acceptance can be slower if switching is constrained by administration protocols or if clinicians need reassurance on stability and handling.

What company commercial strategy supports Halaven’s financial trajectory?

Halaven is commercialized with a focus on maintaining access in late-line oncology. Key revenue drivers are not only clinical but contract-structured:

• hospital formulary inclusion,
• patient flow through infusion centers,
• and rebate alignment that reduces payer pushback.

Typical commercial levers for an older oncology brand

1. contracting and rebate structures to preserve net price,
2. field support for local formulary access,
3. continued line-extension evidence publication to support positioning,
4. supply reliability to reduce infusion center switching risk.

These levers can slow declines even as competitors gain share.

How does Halaven compare with other eribulin or similar oncology options on revenue exposure and market share risk?

Halaven’s revenue exposure is driven by the size of the treatable patient pool in:

• breast cancer late-line settings,
• and sarcoma indications where eribulin competes for utilization based on demonstrated benefit.

Relative risk pattern versus newer oncology agents

Compared with newer targeted agents and antibody-drug conjugates:

• Halaven usually faces more pressure from clinical and payer preference shifts,
• but retains a role where chemotherapy options remain standard and where new agents do not fully displace older options due to biomarker uncertainty, resistance, or eligibility limits.

What this means for financial trajectory

• In markets where newer agents expand, Halaven’s share tends to decline gradually.
• In markets where alternatives are constrained by cost or eligibility, Halaven can maintain a floor.

What FDA milestones and regulatory actions affect Halaven’s commercialization?

Regulatory actions affect market dynamics through:

• labeling changes that enable or restrict patient selection,
• safety communications that affect prescribing,
• and inspection or manufacturing events that can create supply interruptions.

Labeling and line-of-therapy context

For oncology, the revenue tail is sensitive to:

• whether label language supports use after specific prior therapies,
• how broad the eligible population is for each indication,
• and whether subsequent trials update sequencing guidance.

Manufacturing and supply

For injectables, even temporary supply disruptions can accelerate share loss to competitors because infusion centers standardize quickly to maintain throughput.

What patent litigation affects Halaven’s sales and timing of generic competition?

Patent litigation shapes the calendar of generic entry by determining:

• whether generics face automatic stays,
• whether settlements delay entry,
• and whether design-around efforts allow an at-risk launch.

Settlement dynamics that typically matter

When settlements occur, they often include:

• launch-date triggers (carve-outs for certain dosage forms),
• restrictions by strength or formulation,
• and geographic or labeling limitations.

For late-line oncology products, settlements can be a decisive variable because they postpone price erosion.

What commercial revenue trajectory has Halaven shown and what are the near-term market drivers?

Halaven’s financial trajectory typically follows a late-stage branded oncology pattern:

• early growth followed by post-label-maturity stabilization,
• then gradual decline as competitive alternatives expand and sequencing shifts,
• with occasional volatility tied to patent or contracting events.

Near-term drivers

1. Contract and tender cycles: net price outcomes depend on rebates and tender pricing in infusion centers.
2. U.S. payer scrutiny: increased utilization management tends to reduce growth.
3. Competitive sequencing changes: new standards can reduce late-line chemo share.
4. Generic/patent calendar: even without immediate generic entry, expectations can pressure net pricing through internal manufacturer and payer negotiations.

What to watch

• Orange Book-driven events in the U.S. that predict substitution timing.
• Any court decisions that remove remaining barriers to generic entry.
• Announcements from major generic manufacturers about ANDA readiness or launch planning.

Key Takeaways

• Halaven is a small-molecule injectable oncology brand with market dynamics dominated by late-line breast cancer and sarcoma utilization and by payer contracting.
• Generic risk is primarily chemical generic entry, not biosimilars, and depends on Orange Book-listed patent expiry, formulation/process barriers, and any patent litigation or settlements.
• Financial trajectory is structurally sensitive to sequencing shifts, hospital formulary decisions, and net-price erosion from contracting and eventual generic competition.
• Near-term revenue performance hinges on U.S. and major ex-U.S. tender cycles, plus the patent calendar that governs when substitution becomes unavoidable.

FAQs

1. Does Halaven have “skinny label” generic entry risk?
2. How does eribulin’s injectable formulation affect generic design-around strategies?
3. Which indication drives most of Halaven’s late-line revenue exposure?
4. What events typically accelerate oncology brand share loss after patent expiry?
5. How do payer prior-authorization and tender rules influence Halaven net price versus list price?

References

1. FDA. Approved Drug Products with Therapeutic Equivalence Evaluations (Orange Book). U.S. Food and Drug Administration.
2. FDA. Drug Approval Reports and Labeling (Halaven/eribulin). U.S. Food and Drug Administration.
3. Hatch-Waxman Act and associated FDA guidance documents on patent listing and Paragraph IV challenges. U.S. Food and Drug Administration.