US Patent 8,022,106: Tranexamic Acid Modified-Release Formulation Scope, Validity, and Generic-Entry Landscape

US Patent 8,022,106 protects a 650 mg oral modified-release tranexamic acid dosage form designed for administration two or three times daily. Its commercial core is a high-drug-load matrix tablet containing hydroxypropylmethylcellulose, or HPMC, at roughly 10% to 35% by weight and meeting specified dissolution and pharmacokinetic parameters.

The patent’s strongest protection is concentrated in the formulation claims requiring all of the following:

Approximately 650 mg of tranexamic acid per dosage form.
A hydrophilic cellulose-based modified-release polymer.
Polymer content of approximately 10% to 35% by weight.
Controlled dissolution over 15, 45, and 90 minutes.
A two- or three-times-daily dosing profile.
In several claims, HPMC specifically at approximately 15% by weight.
Use for treating menorrhagia.

The patent issued August 23, 2011, from a U.S. application claiming priority to a February 17, 2006 filing. Its ordinary patent term therefore runs to February 17, 2026, subject to any applicable patent-term adjustment or extension recorded in the USPTO and FDA records. The patent is not a biologic patent and does not create biosimilar exclusivity. Generic competition proceeds through the ANDA pathway.

What does US Patent 8,022,106 protect?

The patent protects a controlled-release oral tranexamic acid product rather than tranexamic acid itself. Tranexamic acid is an established antifibrinolytic active ingredient, and the patent does not cover its basic chemical composition.

Claim architecture

The 57 claims fall into six principal groups:

Claim group	Claims	Primary subject matter
Broad dosage-form claims	1-23	Modified-release tranexamic acid dosage forms
HPMC dosage-form claims	24-29	HPMC-specific compositions and dissolution profiles
Broad treatment claims	30-45	Treating menorrhagia with the dosage form of claim 1
HPMC treatment claims	46-51	Menorrhagia treatment using claim 24-26 products
Release-profile treatment claims	52-57	Menorrhagia treatment using claim 27-29 products

Claims 1, 24, 27, and 30 are the most commercially important independent claims.

Independent claim 1

Claim 1 covers a tranexamic acid oral dosage form containing:

Tranexamic acid or a pharmaceutically acceptable salt;
A modified-release material;
A cellulose-derived polymer within specified classes;
Polymer content of about 10% to 35% by weight;
A dissolution profile below 40% at 15 minutes, below 70% at 45 minutes, and at least 50% by 90 minutes; and
Approximately 650 mg of tranexamic acid per dosage form.

The polymer definition includes hydroxyalkylcelluloses, alkylcelluloses, cellulose ethers, partial esters, and mixtures. HPMC is expressly covered but is not required by claim 1.

Independent claim 24

Claim 24 is narrower because it requires HPMC. It retains the 650 mg dose and the principal dissolution limitations.

This claim is likely the most direct product claim against a Lysteda-style generic using an HPMC matrix. A competing product using a different release mechanism or a different polymer could avoid literal infringement, although the doctrine of equivalents may remain relevant depending on the formulation and prosecution history.

Independent claim 27

Claim 27 requires:

Tranexamic acid or a pharmaceutically acceptable salt;
HPMC at approximately 10% to 35% by weight;
Release of approximately 10% to 25% every 15 minutes; and
At least approximately 60% release by 90 minutes.

This claim is narrower than claim 24 because it imposes a continuing release-rate limitation. It may be difficult to establish infringement without comparative dissolution testing under the specified USP conditions.

Independent treatment claims

Claim 30 covers treating menorrhagia by administering a dosage form according to claim 1. Claims 46, 48, 50, and 52 apply similar treatment limitations to the HPMC and release-profile formulations.

The treatment claims reach the commercial dosing regimen of approximately 1,300 mg three times daily through dependent claims 31-34 and related claims 47, 49, 51, 53, 54, 56, and 57.

What formulation characteristics are required for infringement?

A product would generally need to satisfy each limitation of at least one asserted claim. The principal technical tests are summarized below.

Limitation	Scope
Active ingredient	Tranexamic acid or pharmaceutically acceptable salt
Dose	About 650 mg per dosage form
Release mechanism	Modified release
Polymer	Cellulose-based polymer in claim 1; HPMC in claims 19, 24, and 27
Polymer level	About 10%-35% by weight; several dependent claims specify about 15%
Dissolution apparatus	USP 27 Apparatus II, paddle, 50 RPM
Dissolution medium	900 mL water
Temperature	37 ± 0.5°C
Core release limits	Less than about 40% at 15 minutes; less than about 70% at 45 minutes; at least about 50% at 90 minutes
Method of use	Treatment of menorrhagia for the method claims
Commercial dosage schedule	Two or three administrations daily, commonly 1,300 mg three times daily

The dissolution limitations are central. A formulation with the same dose and HPMC but a faster or slower release profile may fall outside the literal scope of claims 24 or 27. Conversely, a generic developer cannot rely only on its own product specification. Infringement analysis would typically require testing under the patent’s stated method and assessment of batch-to-batch variability.

How broad are the dissolution claims in US Patent 8,022,106?

The dissolution language creates both meaningful coverage and a litigation vulnerability.

Claim 1 uses three negative and positive thresholds:

Less than about 40% released at approximately 15 minutes;
Less than about 70% released at approximately 45 minutes;
Not less than about 50% released at approximately 90 minutes.

Claim 2 adds intermediate time points at 30 and 60 minutes. Claim 3 requires approximately 10% to 25% release every 15 minutes. Claim 4 describes an approximately 1% per-minute release rate.

The use of “about” creates a claim-construction issue. Courts generally interpret “about” in view of the specification, prosecution history, technical context, and measurement variability. The patent does not provide an unlimited tolerance. A product releasing 72% at 45 minutes, for example, would present a potential non-infringement position against the literal “less than about 70%” limitation, but the outcome would depend on the intrinsic record and statistical test data.

The specified dissolution method also limits the claim. Results generated using a different medium, apparatus, agitation speed, or temperature may not answer the infringement question directly.

What is the commercial product associated with the patent?

The patent is associated with the Lysteda tranexamic acid 650 mg tablet product used for the treatment of cyclic heavy menstrual bleeding, also known as menorrhagia. Lysteda was approved by the FDA in 2009 under NDA 022430 as an oral tablet containing 650 mg of tranexamic acid.

The FDA-approved regimen is two 650 mg tablets taken three times daily for a maximum of five days during monthly menstruation, corresponding to 1,300 mg per dose and 3,900 mg per day. The product was developed as an oral alternative to more frequent immediate-release tranexamic acid dosing.

Regulatory item	Data
Product	Lysteda
Active ingredient	Tranexamic acid
Dosage form	650 mg oral tablet
NDA	022430
FDA approval	2009
Indication	Cyclic heavy menstrual bleeding
Typical regimen	1,300 mg three times daily
Regulatory pathway for generics	ANDA
Biosimilar pathway	Not applicable

FDA labeling identifies gastrointestinal and neurologic adverse events, including headache, abdominal pain, back pain, muscle or joint pain, and nasal or sinus symptoms. The patent claims seek to distinguish the modified-release profile from immediate-release administration based partly on gastrointestinal tolerability and plasma-concentration behavior. The clinical relevance of those distinctions remains dependent on the evidence supporting each asserted claim.

When does US Patent 8,022,106 lose exclusivity?

The patent’s ordinary expiration date is expected to be February 17, 2026, based on the earliest claimed priority date of February 17, 2006 and the 20-year U.S. patent term under 35 U.S.C. § 154.

Event	Date
Earliest claimed priority	February 17, 2006
U.S. patent application	2007-era filing, with later prosecution history
Patent issued	August 23, 2011
Expected ordinary expiration	February 17, 2026
FDA new-drug exclusivity	Expired
Practical generic timing	Dependent on patent certifications, litigation, and settlement terms

Patent expiration does not necessarily equal the earliest possible generic launch date. An ANDA applicant may launch before expiration after prevailing in Paragraph IV litigation, obtaining a favorable settlement date, or successfully avoiding the patent. Conversely, other listed patents or regulatory exclusivity may delay approval or commercial launch.

What is the Orange Book status of Lysteda and patent 8,022,106?

Lysteda is an FDA-approved small-molecule drug listed in the Orange Book. Patent 8,022,106 has been associated with the Lysteda product and its modified-release formulation.

Orange Book analysis should separate three issues:

Whether the patent is currently listed against NDA 022430;
Whether the patent’s expiration date has been updated;
Whether other patents, including continuation or related formulation patents, remain listed.

The Orange Book controls the Hatch-Waxman patent-certification framework for an ANDA applicant. A generic applicant must certify against each listed patent. A Paragraph IV certification alleges that a listed patent is invalid, unenforceable, or not infringed. Notice of a Paragraph IV certification can trigger a 30-month stay if the NDA holder or patent owner files suit within the statutory period under 21 U.S.C. § 355(j)(5)(B)(iii).

Which companies have challenged the Lysteda patent estate?

Public litigation surrounding Lysteda has included ANDA activity directed to generic tranexamic acid 650 mg modified-release tablets. Ferring-related entities asserted U.S. Patent 8,022,106 against Watson Laboratories in federal court proceedings arising from an ANDA challenge.

The principal legal issues in this type of case include:

Whether the proposed generic meets the claimed dissolution profile;
Whether HPMC or another cellulose polymer is present at the claimed concentration;
Whether the patent claims would have been obvious in view of prior modified-release tranexamic acid formulations;
Whether the patent specification supports the full breadth of the dissolution and pharmacokinetic ranges;
Whether method claims can be induced by the generic label; and
Whether a settlement permits launch before patent expiration.

A definitive competitive analysis must distinguish an actual final judgment from a preliminary ruling, a consent judgment, a confidential settlement, or an ANDA filing that never resulted in launch. The patent number alone does not establish the current status of every generic applicant.

How strong is the patent estate for tranexamic acid modified release?

Strengths

The patent has several commercially relevant strengths:

It targets a differentiated 650 mg modified-release product rather than the unprotected active ingredient.
It combines composition, dissolution, pharmacokinetic, side-effect, and method-of-treatment limitations.
Claims 24 and 27 directly target HPMC matrix formulations that resemble the commercial product.
The 1,300 mg three-times-daily menorrhagia regimen is reflected in multiple dependent treatment claims.
Product claims do not require proof of the patient’s diagnosis or actual clinical outcome.

Weaknesses

The estate also has material limitations:

The 650 mg dose and narrow dissolution windows reduce coverage against non-matching designs.
The claims depend heavily on functional and pharmacokinetic parameters that may require extensive testing.
HPMC is a conventional hydrophilic matrix polymer, creating potential obviousness arguments when combined with known tranexamic acid dosing and modified-release technology.
Claims requiring reduced side effects or specified pharmacokinetics may raise enablement, written-description, and proof-of-infringement issues.
The patent term is near expiration based on the ordinary 20-year calculation.
Immediate-release tranexamic acid products do not necessarily infringe because the patent is directed to modified-release dosage forms.

Overall, the patent is strongest against a 650 mg HPMC matrix tablet intentionally engineered to match the Lysteda release profile. It is weaker against alternative polymers, osmotic systems, coated multiparticulates, different strengths, materially different release profiles, or products labeled only for non-menorrhagia indications.

What generic launch scenarios exist?

Scenario	Effect on originator
Generic matches HPMC and dissolution profile	High infringement risk before patent expiry
Generic uses a different polymer	Potential design-around, subject to claim 1 and equivalents analysis
Generic changes release kinetics materially	Potential non-infringement, with bioequivalence implications
Generic launches after February 2026	Patent-based barrier largely removed, subject to other listed patents
Generic files Paragraph IV and wins	Possible pre-expiry launch
Generic settles with a later launch date	Entry controlled by settlement terms
Generic obtains approval but does not launch	Limited immediate commercial impact
Generic uses an immediate-release product	Usually outside the formulation claims, but not necessarily substitutable as an AB-rated product

An ANDA product must demonstrate pharmaceutical equivalence and bioequivalence to the reference listed drug. A formulation design-around that changes the release profile may not qualify as an ANDA for the same reference product and could require a different regulatory strategy.

Are biosimilar risks relevant to this patent?

No. Tranexamic acid is a chemically synthesized small molecule. FDA competition occurs through ANDAs, not biosimilar applications under the Public Health Service Act.

The relevant competitive risks are:

Paragraph IV generic challenges;
Paragraph III certifications with launch after patent expiration;
Formulation design-arounds;
Authorized generic competition;
Non-U.S. generic manufacturers entering markets where U.S. patent rights do not apply; and
Substitution pressure from immediate-release tranexamic acid where physicians accept different dosing.

What geographic coverage does the patent provide?

US Patent 8,022,106 provides rights only in the United States. It does not independently block products in Canada, Europe, Japan, Australia, or emerging markets.

Foreign protection would require separately issued national or regional patents in the relevant family. Patent expiration, opposition, maintenance, claim scope, and litigation outcomes must be assessed jurisdiction by jurisdiction. The U.S. patent cannot be used to prevent manufacturing or sale entirely outside the United States unless another enforceable jurisdictional right applies.

What manufacturing and intellectual-property barriers remain?

The active ingredient is off-patent and chemically accessible. The principal barrier is formulation development.

A generic developer would need to control:

High drug loading, because tranexamic acid represents a large proportion of the tablet weight;
Matrix integrity during hydration;
Compression and friability at large tablet sizes;
Uniformity of HPMC distribution;
Dissolution across the full shelf-life period;
Bioequivalence after food and under fasting conditions;
Manufacturing-scale variation; and
Potential infringement under equivalent-release or equivalent-polymer theories.

A formulation containing approximately 15% HPMC and approximately 60% to 90% tranexamic acid by weight is particularly close to the express limitations in claims 25, 26, 28, and 29.

What is the revenue exposure from loss of patent protection?

Ferring is a private company and does not provide the same product-level revenue disclosure as a public pharmaceutical issuer. Public filings therefore do not provide a consistently reported, stand-alone Lysteda revenue figure suitable for precise exposure modeling.

The commercial exposure depends on:

Lysteda’s remaining U.S. sales before generic entry;
The number of approved ANDAs;
Whether generic products are therapeutically substitutable;
The timing of any authorized generic;
Payer preference for generic tranexamic acid;
The extent of off-label and non-menorrhagia use; and
Any additional listed patents or settlement restrictions.

The near-term value of US Patent 8,022,106 is primarily defensive. Its remaining term is short relative to the development timeline for a new formulation, which reduces the economic value of a late-stage licensing transaction unless the transaction includes regulatory, manufacturing, brand, or foreign-market rights.

Key Takeaways

US Patent 8,022,106 protects modified-release oral tranexamic acid formulations, not tranexamic acid itself.
The commercial center of gravity is a 650 mg HPMC matrix tablet used for cyclic heavy menstrual bleeding.
Claims 24 and 27 are the most direct HPMC and dissolution-profile claims.
The specified USP dissolution test is central to infringement analysis.
The method claims cover treatment of menorrhagia, including 1,300 mg three-times-daily administration.
The patent’s ordinary expiration date is February 17, 2026, subject to the official USPTO term record.
Generic competition is governed by the ANDA and Paragraph IV framework.
Biosimilar competition is irrelevant because tranexamic acid is a small molecule.
The patent is strongest against a Lysteda-like HPMC matrix formulation and weaker against materially different release systems.
Product-level revenue exposure cannot be reliably quantified from public company reporting alone.

FAQs About US Patent 8,022,106

Does US Patent 8,022,106 cover immediate-release tranexamic acid tablets?

No. The claims require modified release, specified dissolution behavior, or a dosage form meeting the claimed formulation characteristics. A conventional immediate-release tranexamic acid tablet generally falls outside the core formulation claims.

Can a generic avoid the patent by using a polymer other than HPMC?

Potentially. Claims 24 and 27 require HPMC, but claim 1 covers a broader group of cellulose-based modified-release materials. A non-HPMC formulation would require a limitation-by-limitation analysis against claim 1 and the doctrine of equivalents.

Does changing the tranexamic acid strength avoid infringement?

It may avoid claims expressly requiring approximately 650 mg per dosage form. The result depends on how the court construes “about 650 mg” and whether other claims or related patents cover the alternative strength.

Is a 1,300 mg dose itself patented by US Patent 8,022,106?

No. The patent does not broadly monopolize the 1,300 mg dose. The relevant claims combine the dose with a claimed modified-release dosage form and, in some cases, treatment of menorrhagia.

Can a company sell tranexamic acid outside the United States after US Patent 8,022,106 expires?

U.S. patent expiration does not determine foreign rights. Sales and manufacturing in each country depend on that jurisdiction’s patent family, regulatory requirements, and local exclusivity status.

References

Food and Drug Administration. (2009). Lysteda (tranexamic acid) tablets, 650 mg: Prescribing information. U.S. Department of Health and Human Services.
Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations. U.S. Department of Health and Human Services.
United States Patent and Trademark Office. (2011). U.S. Patent No. 8,022,106, Modified release tranexamic acid formulations.
United States Code, 35 U.S.C. § 154. Patent term.
United States Code, 21 U.S.C. § 355. New drug application and abbreviated new drug application requirements.
Ferring B.V. v. Watson Laboratories, Inc., 765 F.3d 205 (3d Cir. 2014).

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Japan	2008508275	⤷ Start Trial
Japan	2008508276	⤷ Start Trial
Japan	2011168596	⤷ Start Trial
Japan	2014193878	⤷ Start Trial
Japan	5000504	⤷ Start Trial
Japan	5205053	⤷ Start Trial
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Details for Patent: 8,022,106

Summary for Patent: 8,022,106