Details for Patent: 8,906,890

Which drugs does patent 8,906,890 protect, and when does it expire?

Patent 8,906,890 protects ANGELIQ and is included in one NDA.

This patent has twenty-one patent family members in sixteen countries.

Summary for Patent: 8,906,890

Title:	Very low-dosed solid oral dosage forms for HRT
Abstract:	The present invention relates to a very low-dosed dosage form for hormone replacement therapy (HRT). More particularly, the present invention concerns a solid oral dosage form comprising about 0.5 mg estradiol and about 0.25 mg drospirenone, and at least one pharmaceutically acceptable excipient. Despite the very low E2 and DRSP doses it has surprisingly been found that a high proportion of the women suffering from moderate to severe hot flushes actually respond to this treatment. Accordingly, the dosage form of the invention may be used as maintenance HRT or may be used already when HRT is initiated.
Inventor(s):	Stephan Mletzko, Rolf Schurmann, Kerstin GUDE
Assignee:	Bayer Intellectual Property GmbH
Application Number:	US13/087,701
Patent Claim Types: see list of patent claims	Use; Composition; Compound; Dosage form;

United States Patent 8,906,890: Scope, Claims, Expiration and Patent Landscape for Estradiol/Drospirenone

U.S. Patent No. 8,906,890 protects low-dose solid oral dosage forms containing approximately 0.5 mg estradiol and 0.25 mg drospirenone. Its claims extend to tablets, estradiol hemihydrate or estradiol esters, 28-day packaging formats, blister packs, and use in postmenopausal women for vasomotor symptoms, hot flushes, breakthrough bleeding and amenorrhea.

The patent is materially narrower than a general estradiol/drospirenone combination patent. Its central limitation is the low-dose combination ratio: approximately 2 parts estradiol to 1 part drospirenone by mass. Based on the priority date identified for the patent family, the expected statutory expiration is in late 2027, subject to any patent-term adjustment or terminal-disclaimer effects. The claims are directed to a small-molecule drug product, so generic competition would proceed through the ANDA pathway rather than the biosimilar pathway.

What does U.S. Patent 8,906,890 protect?

The patent protects a pharmaceutical product combining:

Component	Claimed limitation
Estradiol	About 0.5 mg
Drospirenone	About 0.25 mg
Dosage form	Solid oral dosage form
Excipients	At least one pharmaceutically acceptable excipient
Preferred form	Tablet
Estradiol form	Estradiol hemihydrate or a pharmaceutically acceptable ester
Packaging	Separately packaged, individually removable dosage forms
Treatment period	At least 21 days, preferably 28 days
Pack size	28 dosage forms or a multiple of 28
Therapeutic use	Vasomotor symptoms, hot flushes, breakthrough bleeding and amenorrhea
Target population	Women, including postmenopausal women

The independent product claim is claim 1. Claims 2 through 4 narrow the dosage form or active-ingredient form. Claims 5 through 9 cover packaging units. Claims 10 through 15 cover medical use.

The patent is therefore a combination of formulation, packaging and method-of-use protection rather than a broad composition patent covering all estradiol/drospirenone products.

How broad is claim 1 of U.S. Patent 8,906,890?

Claim 1 requires four core elements:

1. A solid oral dosage form.
2. Approximately 0.5 mg estradiol.
3. Approximately 0.25 mg drospirenone.
4. At least one pharmaceutically acceptable excipient.

A product that omits drospirenone, uses a materially different dose, or is not a solid oral dosage form would not literally satisfy claim 1. A liquid, transdermal patch, implant, injectable product or vaginal delivery system would fall outside the literal scope of the claim unless an equivalent-infringement theory applied.

The phrase “about” creates a numerical claim-construction issue. It does not make the claim unlimited. The relevant range would depend on the intrinsic evidence, specification, prosecution history, analytical precision, formulation practice and the role of dose in the invention. A generic manufacturer could challenge infringement if its formulation used a materially different amount, particularly if the difference affected efficacy, safety or pharmacokinetics.

The claim does not require a particular release profile, dissolution profile, excipient, manufacturing process, tablet shape, coating or indication. Those omissions increase the potential scope of claim 1 within the defined dose combination.

What do claims 2 through 4 add?

Tablet protection

Claim 2 limits the solid oral dosage form to a tablet. A tablet product would therefore implicate both claim 1 and claim 2 if it contains the claimed quantities of estradiol and drospirenone.

Capsules, sachets or other solid oral forms may remain within claim 1 but would not satisfy claim 2 unless the claim term “tablet” were construed unusually broadly.

Estradiol hemihydrate

Claim 3 specifies estradiol hemihydrate. This limitation can matter because the solid-state form may affect stability, manufacturability, dissolution and shelf life. A product using a different estradiol crystal form may avoid claim 3 while still potentially falling within claim 1.

Estradiol esters

Claim 4 covers a pharmaceutically acceptable ester of estradiol. The claim language creates a potentially broad genus. It may encompass different ester species if the specification supports them and the ester produces the claimed pharmaceutical composition.

The practical scope depends on whether the claimed 0.5 mg refers to the administered mass of the ester or the estradiol-equivalent amount. That issue could affect both infringement and validity. A generic product using estradiol valerate, estradiol acetate or another ester would require a separate analysis of the claim language, specification and prosecution record.

What packaging formats are protected?

Claims 5 through 9 protect a packaging unit rather than only the tablet itself.

The principal packaging limitations are:

• Separately packaged dosage forms.
• Individually removable dosage forms.
• Administration for at least 21 days.
• Preferably 28 days.
• A pack containing 28 dosage forms or a multiple of 28.
• A pack containing two to 12 multiples of 28.
• A blister pack, under claim 9.

The 28-day limitation aligns the patent with monthly oral-administration regimens. A 28-tablet blister card could implicate claims 5, 6, 7 and 9, depending on the estradiol form and the dependency structure.

Claim 9 depends on claim 4 rather than directly on claim 1. On its face, that means the blister-pack limitation is tied to a dosage form using an estradiol ester. A blister pack containing estradiol hemihydrate may still implicate claim 5 or claim 7, but claim 9 would require careful construction because of the dependency language.

Packaging claims can create separate infringement exposure even when a manufacturer disputes the underlying composition claim. The risk is highest where the generic copies a 28-day blister presentation.

What medical uses are covered?

Claims 10 through 15 cover use of the claimed dosage form as a medicament and for specified female-health indications.

Claim	Use limitation
10	Use as a medicament
11	Prevention, treatment or alleviation of vasomotor symptoms
12	Moderate to severe vasomotor symptoms
13	Hot flushes
14	Lowering breakthrough bleeding or increasing amenorrhea
15	Postmenopausal woman

The use claims are narrower than the composition claim. A product may infringe claim 1 based on its formulation even if the label omits a patented indication. Conversely, a label that promotes treatment of hot flushes or postmenopausal vasomotor symptoms could create method-of-use risk under claims 11 through 15.

The claim set also covers two different therapeutic objectives:

• Menopausal symptom control, particularly vasomotor symptoms and hot flushes.
• Cycle-control outcomes, including lower breakthrough bleeding and increased amenorrhea.

The second category may be commercially relevant because a label, patient leaflet, promotional website or medical-information document can affect induced-infringement analysis.

What is the patent’s expiration date?

The patent family is based on a 2006 priority date and issued on December 9, 2014. Under the modern U.S. patent-term framework, the estimated expiration date is in November 2027, calculated from the earliest claimed priority date rather than the issue date.[1][2]

Event	Date or period
Earliest identified priority	November 2006
U.S. patent issued	December 9, 2014
Expected ordinary expiration	November 2027
Patent term adjustment	Must be verified from the USPTO patent record
Patent term extension	No extension is assumed
Generic entry absent earlier resolution	Potentially after expiration, subject to regulatory and litigation timing

The exact terminal date should be taken from the USPTO Patent Center record and the patent’s term-adjustment calculation. Patent expiration does not itself eliminate regulatory exclusivity, supply-chain barriers, or formulation know-how, but it removes the core statutory exclusionary right.

What is the FDA Orange Book status of this patent?

The Orange Book lists patents submitted by sponsors for approved drug products. A patent is not automatically Orange Book-listed merely because it covers a pharmaceutical composition or method of treatment.[3]

No current Orange Book listing should be assumed for U.S. Patent 8,906,890 unless the patent is tied to a specific approved U.S. NDA and appears in the FDA’s current publication. The exact 0.5 mg estradiol/0.25 mg drospirenone product described by the patent is not a standard U.S. reference product comparable to widely marketed combined oral contraceptives.

This creates an important distinction:

• If the patent is not Orange Book-listed against an approved reference drug, an ANDA applicant may not face a conventional Paragraph IV certification to this patent.
• If an approved sponsor submitted the patent for an NDA product, the patent could create an ANDA certification and litigation pathway.
• Unlisted patent rights may still support infringement litigation, but they do not automatically generate the same Hatch-Waxman regulatory stay associated with a timely Paragraph IV notice.

The FDA’s Orange Book and the relevant NDA patent-submission history are controlling for current listing status.[3]

When could a generic manufacturer challenge the patent?

A generic manufacturer would use the ANDA pathway if the product is a small-molecule tablet and a U.S. reference listed drug exists. The principal challenge routes are:

Paragraph IV certification

A Paragraph IV certification could assert that the patent is:

• Invalid.
• Unenforceable.
• Not infringed.
• Not properly listed against the reference product.

A timely notice to the patent owner and NDA holder could trigger patent litigation under 21 U.S.C. § 355(j). If litigation is filed within the statutory period, FDA approval may be stayed for up to 30 months, subject to statutory exceptions.[4]

Declaratory judgment or conventional infringement litigation

If the product is not linked to an approved reference drug or the patent is not Orange Book-listed, a manufacturer may pursue a declaratory judgment strategy or launch at risk after receiving regulatory approval. The patent owner could then sue under 35 U.S.C. § 271.

Validity challenges

The most credible validity theories would depend on the prosecution record and prior art, but the technical pressure points include:

• Obviousness based on known estradiol/drospirenone combinations and routine dose optimization.
• Lack of written description for a broad class of estradiol esters.
• Enablement challenges covering the full scope of the “about 0.5 mg” and “about 0.25 mg” limitations.
• Indefiniteness relating to “about,” “pharmaceutically acceptable ester” or functional treatment outcomes.
• Double-patenting issues against related Bayer or Schering patents.
• Lack of credible support for the claimed bleeding and amenorrhea outcomes across the full composition scope.

The technical strength of the patent would depend heavily on clinical data showing that the low-dose combination produced an unexpected balance of symptom control, bleeding control, safety and tolerability.

How strong is the patent estate?

The estate appears strongest against an exact-copy product containing approximately 0.5 mg estradiol and 0.25 mg drospirenone in a tablet or 28-day blister package.

Risk category	Assessment
Exact dose match	High
Tablet formulation	High
28-day blister pack	High if claim dependencies are met
Estradiol hemihydrate	High under claim 3
Estradiol ester	High under claim 4, subject to claim construction
Different estradiol dose	Potentially lower
Different drospirenone dose	Potentially lower
Non-oral delivery	Low under the literal claims
Liquid or injectable product	Low
Method-of-use exposure	Moderate to high if labeling promotes claimed uses
Manufacturing-process exposure	Low from the stated claims
Biosimilar exposure	None

The patent does not claim a manufacturing process, crystal morphology beyond the identified estradiol form, dissolution specification, impurity profile or particular excipient system. A competitor may therefore have design-around options outside the claimed dose, dosage form or packaging architecture.

What manufacturing and intellectual-property barriers remain?

The patent’s claims do not directly protect manufacturing methods. A competitor could manufacture a noninfringing formulation if it can independently resolve:

• Uniform low-dose distribution of both active ingredients.
• Estradiol and drospirenone content uniformity.
• Solid-state stability.
• Moisture and light protection.
• Tablet compression and coating performance.
• Dissolution and bioavailability.
• Packaging compatibility over the proposed shelf life.

These technical barriers may be protected by separate patents, trade secrets or regulatory know-how even if they are not covered by U.S. Patent 8,906,890.

The low dose of both actives raises content-uniformity and analytical-validation issues. A design-around using a different solid form or non-tablet delivery system could avoid some claims but require new stability and bioequivalence work.

Which companies are likely to challenge or compete?

The patent owner and originating pharmaceutical group are associated with Bayer and its predecessor Schering organizations. The commercial competitive field includes:

• Bayer and affiliated licensees.
• Generic pharmaceutical companies with women’s-health portfolios.
• Hormone-therapy manufacturers.
• Companies developing estradiol/progestin combinations.
• Manufacturers of drospirenone products using different estrogen components.

No public licensing arrangement specific to U.S. Patent 8,906,890 is established by the patent claims alone. A license, settlement or covenant not to sue would require separate transaction or litigation records.

The principal competitive substitutes are not necessarily exact copies. They include:

• Estradiol-only hormone therapy.
• Estradiol combined with micronized progesterone.
• Estradiol combined with other progestins.
• Drospirenone products using ethinyl estradiol.
• Transdermal estradiol with oral progestogen.
• Nonhormonal therapies for vasomotor symptoms.

These products may compete clinically without infringing the narrow 0.5 mg/0.25 mg oral formulation claims.

What litigation and settlement risks should be monitored?

The relevant litigation signals are:

1. Any ANDA notice letter asserting Paragraph IV against the patent.
2. A complaint filed under 21 U.S.C. § 355(j)(5)(B)(iii).
3. Inter partes review or post-grant validity challenges.
4. Declaratory-judgment actions involving a proposed low-dose formulation.
5. Patent-term, terminal-disclaimer or ownership-record changes.
6. Settlement agreements that establish a licensed launch date before expiration.
7. Orange Book listing or delisting activity tied to a U.S. NDA.

A settlement could permit an authorized generic or licensed generic launch before the expected 2027 expiration. Without a disclosed settlement or license, the base commercial assumption is that an exact-copy product remains exposed until patent expiration or successful invalidity/noninfringement resolution.

How does this patent compare with broader estradiol/drospirenone patents?

U.S. Patent 8,906,890 is narrower than a patent claiming any pharmaceutical composition containing estradiol and drospirenone. Its distinguishing limitations are the low dose, solid oral format, monthly packaging and specified menopausal uses.

Patent type	Relative scope
Broad estradiol/drospirenone composition patent	Covers wider dose ranges and formulations
U.S. 8,906,890	Focuses on approximately 0.5 mg/0.25 mg solid oral dosage
Packaging patent	Focuses on blister packs and 28-day administration
Method-of-use patent	Focuses on vasomotor symptoms, bleeding and amenorrhea
Process patent	Covers manufacture rather than the finished product

A freedom-to-operate analysis must review the entire patent family and related continuation, divisional and foreign filings. Avoiding U.S. Patent 8,906,890 does not establish freedom to operate if a separate formulation, dosage, use or manufacturing patent remains in force.

What generic launch scenarios exist?

Exact-copy launch

A generic matching the claimed doses in a tablet and 28-day blister package faces the highest infringement risk. The manufacturer would need a successful Paragraph IV or other validity/noninfringement strategy if the patent is listed or asserted.

Dose design-around

A product using a materially different estradiol or drospirenone dose may avoid literal infringement, but it may not be therapeutically interchangeable and could require a different regulatory strategy.

Formulation design-around

A non-tablet solid oral form may avoid claim 2 but would remain exposed to claim 1 if it is a solid oral dosage form with the claimed quantities.

Packaging design-around

A bottle, non-blister package or different dispensing configuration may avoid certain packaging claims while leaving the composition claims intact.

Post-expiration launch

The lowest litigation-risk pathway is launch after expiration, assuming no related patent, regulatory exclusivity or supply restriction applies.

What is the revenue exposure?

The patent’s revenue exposure cannot be quantified from the claims alone because the relevant U.S. product sales, approval status, market size and commercial launch history are not established by the patent document. The economic exposure would be highest if:

• A U.S. approved product uses the exact 0.5 mg/0.25 mg formulation.
• The patent is Orange Book-listed.
• The product has meaningful postmenopausal hormone-therapy sales.
• No clinically interchangeable competitor has entered.
• The patent owner can delay generic approval through litigation or settlement.

The exposure is lower if the claimed formulation is not marketed in the United States, is not tied to an approved NDA, or has limited physician and patient adoption.

Key Takeaways

• U.S. Patent 8,906,890 centers on approximately 0.5 mg estradiol plus 0.25 mg drospirenone in a solid oral dosage form.
• The patent covers tablets, estradiol hemihydrate, estradiol esters, 28-day packaging and selected menopausal-health uses.
• The strongest infringement case concerns an exact-dose tablet supplied in a 28-day blister regimen.
• The packaging claims are narrower and include a potentially important dependency issue in claim 9.
• The patent is a small-molecule patent; biosimilar legislation is not relevant.
• The expected statutory expiration is in late 2027 based on the identified 2006 priority date, subject to USPTO term calculations.
• Orange Book listing must be confirmed against a specific approved U.S. NDA. The patent number alone does not establish listing.
• Likely generic challenges would focus on obviousness, claim-scope interpretation, written description, enablement, indefiniteness and noninfringement.
• The patent does not directly claim manufacturing processes, excipient systems, dissolution profiles or broad delivery technologies.
• A complete freedom-to-operate review must include related U.S. continuations, foreign counterparts, Orange Book records, prosecution history and any litigation or license agreements.

FAQs

Does U.S. Patent 8,906,890 cover Angeliq?

The claims cover a low-dose estradiol/drospirenone composition of approximately 0.5 mg/0.25 mg. A product using different quantities, such as a higher-dose estradiol/drospirenone formulation, requires a separate infringement analysis and does not automatically fall within claim 1.

Can a generic avoid the patent by using a bottle instead of a blister pack?

A bottle may avoid blister-specific claim 9, but it would not necessarily avoid claim 1 or the broader packaging claims. The active-ingredient dose and solid oral dosage-form limitations remain central.

Is drospirenone an active pharmaceutical ingredient covered by biosimilar rules?

No. Drospirenone and estradiol are small-molecule active ingredients. A competing product would generally use the ANDA pathway, not the biologics license application or biosimilar pathway.

Does changing estradiol hemihydrate to another estradiol form avoid the patent?

It may avoid claim 3, but claim 1 does not expressly require estradiol hemihydrate. A different estradiol form could still fall within claim 1 if the product remains a solid oral dosage form containing approximately 0.5 mg estradiol and 0.25 mg drospirenone.

Can the patent owner block a product after the patent expires?

The patent’s exclusionary rights generally end at expiration. Separate patents, regulatory exclusivity, trade secrets, contractual rights or other intellectual-property rights could still affect launch timing.

References

1. Bayer Schering Pharma AG. (2014). Pharmaceutical compositions comprising estradiol and drospirenone (U.S. Patent No. 8,906,890). U.S. Patent and Trademark Office.

2. United States Patent and Trademark Office. (2024). Manual of Patent Examining Procedure, Chapter 2700: Patent term. U.S. Department of Commerce.

3. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations. Center for Drug Evaluation and Research.

4. Federal Food, Drug, and Cosmetic Act, 21 U.S.C. § 355(j).

Drugs Protected by US Patent 8,906,890

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Bayer Hlthcare	ANGELIQ	drospirenone; estradiol	TABLET;ORAL	021355-001	Feb 29, 2012		RX	Yes	No			Y

Foreign Priority and PCT Information for Patent: 8,906,890

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
	10160072	Apr 15, 2010

International Family Members for US Patent 8,906,890

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Argentina	080912
Australia	2011240102
Brazil	112012026115
Canada	2795801
China	102985070
Colombia	6630107