United States Patent 6,747,019: Claim Scope, Exclusivity, and Hormone-Replacement-Therapy Patent Landscape

U.S. Patent No. 6,747,019 covers a cyclic hormone-replacement regimen using three consecutive estrogen-dominant doses followed by three consecutive progestogen-dominant doses. The core dosage concept is approximately 1 mg per day of 17β-estradiol during both phases, with approximately 90 μg per day of norgestimate added during the progestogenic phase. The patent claims the formulation, package, regimen, and treatment method.

The patent issued June 8, 2004, and its standard 20-year term appears to have expired in 2020, subject to any patent-term adjustment or terminal-disclaimer information recorded in the official prosecution file. Because the patent term has ended, U.S. infringement risk from the issued claims is generally historical rather than prospective.

What does U.S. Patent 6,747,019 protect?

The patent protects a six-day repeating treatment architecture rather than a single active ingredient.

Claim element	Required feature
Patient population	Female in need of hormone replacement therapy
First phase	Three consecutive daily doses, or equivalent
First-phase activity	Relatively dominant estrogenic activity
First-phase estrogen	About 1 mg/day estrogenic activity equivalent to 17β-estradiol
Second phase	Three consecutive daily doses, or equivalent
Second-phase activity	Relatively dominant progestogenic activity
Second-phase composition	About 1 mg/day estrogenic activity plus about 90 μg/day progestogenic activity equivalent to norgestimate
Principal dosage form	Oral dosage, with tablets claimed in dependent claims
Claimed article	Pharmaceutical preparation and package
Claimed conduct	Administration method for hormone replacement therapy

The inventive center is the alternating sequence. A product containing estradiol and norgestimate could avoid the patent if it did not use the claimed three-day estrogen-dominant and three-day progestogen-dominant arrangement, subject to the doctrine of equivalents.

How many independent claims does Patent 6,747,019 contain?

The patent has three principal independent claim categories:

Claims 1 and 2 cover a pharmaceutical preparation or dosage regimen.
Claims 7 and 8 cover a package containing the regimen.
Claims 13 and 14 cover a method of treating a woman with the regimen.

Claims 19 and 22 add more specific composition language but depend on the preparation and package claim structures, respectively.

Independent claim group	Claim numbers	Legal subject matter
Preparation or dosage regimen	1, 2	Doses arranged in alternating phases
Package	7, 8	Packaged doses arranged in the claimed sequence
Treatment method	13, 14	Administration of the claimed regimen
Narrower composition variants	19, 22	Express estradiol and norgestimate amounts

The claims are highly overlapping. Claims 2, 8, and 14 recite the more specific three-dose/three-dose sequence. Claims 19 and 22 expressly identify the active quantities instead of relying principally on pharmacological equivalence.

What is the scope of independent claim 1?

Claim 1 is a composition-and-regimen claim. It requires a pharmaceutical preparation containing multiple doses arranged for alternating administration. The first phase contains only an estrogenically active substance at an activity equivalent to approximately 1 mg/day of 17β-estradiol. The second phase contains both estrogenic and progestogenic activity, with the progestogenic activity equivalent to approximately 90 μg/day of norgestimate.

The claim does not require:

A particular brand name;
A particular tablet color;
A 28-day package;
A specific excipient;
A particular manufacturing process;
A particular indication beyond hormone replacement therapy;
A particular estrogen molecule if the claimed activity equivalence is met; or
Norgestimate itself, because the claim is expressed partly through progestogenic activity equivalence.

The phrase “plurality of doses” leaves the total number of cycles open. The minimum practical configuration is one three-dose estrogen phase followed by one three-dose combination phase, but a commercial package could contain multiple repetitions.

How do claims 2 through 6 narrow the patent?

Claim 2 specifies consecutive daily administration and makes the three-dose phase structure explicit. Claims 5 and 6 narrow the preparation to oral administration and then to tablets.

Claim 3 adds pharmacological selection criteria for the progestogen. The progestogen must bind to progestin receptors, have poor affinity for androgen receptors, and lack affinity for sex-hormone-binding globulin. This language attempts to distinguish progestogens by receptor profile rather than chemical identity alone.

Claim 4 supplies a Markush list of possible estrogenic and progestogenic substances. The listed estrogens include:

Ethinylestradiol and derivatives;
Estrone and estrone salts;
Estradiol;
Estriol;
Natural estrogen esters; and
Other synthetic estrogens.

The listed progestogens include:

Desogestrel;
Dydrogesterone;
Medroxyprogesterone acetate;
Cyproterone acetate;
Chlormadinone acetate;
Dienogest;
Trimegestone;
Drospirenone; and
Norgestrel-related compounds.

The claim text contains apparent typographical errors, including “17 D-acetyl norgestimate,” “magestrol acetate,” “drosperinone,” and “nomagestrel.” The prosecution history and issued patent specification would control whether these errors can be corrected through claim construction or whether they create indefiniteness or scope disputes.

What do the package claims protect?

Claims 7 through 12 cover a physical package containing the phased regimen. These claims target a blister pack, wallet pack, dispenser, or comparable presentation in which the doses are arranged in the required order.

The package claims are commercially important because they do not focus solely on the chemical contents. A manufacturer could face a package-claim issue even if the product’s active ingredients are known, provided that the package organizes the doses into the claimed alternating phases.

The package claims require:

Three estrogen-dominant doses;
Three combination doses;
Approximately 1 mg/day estrogenic activity in each phase;
Approximately 90 μg/day norgestimate-equivalent progestogenic activity in the second phase; and
A package arrangement suitable for sequential administration.

A loose supply of tablets without an organized sequence would present a stronger noninfringement position than a labeled blister package directing the exact patented schedule.

What do the method claims cover?

Claims 13 through 18 cover treatment of a female requiring hormone replacement therapy. The method requires administering the same alternating regimen.

The method claims are narrower in one respect and broader in another:

They are narrower because infringement requires performance of the treatment method.
They may be broader commercially because liability can arise from administering the regimen even where the product presentation differs.

Claims 17 and 18 narrow the method to oral tablets. Claims 15 and 16 repeat the receptor-profile and Markush-substance limitations.

A method claim would generally require evidence that the claimed regimen was administered. For a branded product, prescribing instructions, labeling, patient directions, and pharmacy dispensing records could become relevant. A product claim or package claim can be easier to enforce against a manufacturer because the accused article itself provides the central evidence.

What do claims 19 through 24 add?

Claims 19 through 24 are the most commercially specific claims in the supplied set. They require:

Approximately 1 mg/day of 17β-estradiol in the estrogen-dominant phase; and
Approximately 1 mg/day of 17β-estradiol plus approximately 90 μg/day of norgestimate in the progestogen-dominant phase.

Claims 20, 21, 23, and 24 narrow those embodiments to oral and tablet forms.

These claims are more closely aligned with a product containing estradiol and norgestimate than claims that rely on activity equivalence. They also create potential proof issues concerning the meaning of “about,” the actual dose per tablet, salt or ester forms, and whether the product’s pharmacological activity is equivalent to the specified reference amounts.

What formulations are protected by Patent 6,747,019?

The patent primarily protects oral solid dosage forms, especially tablets, but the broadest claims are not limited to tablets. The claim hierarchy covers:

Formulation type	Coverage position
Oral tablets	Expressly covered by claims 6, 12, 18, 21, and 24
Other oral dosage forms	Potentially covered by claims 5, 11, 17, and 20
Nonoral dosage forms	Potentially covered by the broader independent claims if all activity and sequencing limitations are met
Transdermal estrogen plus oral progestogen	Requires careful analysis of whether the “preparation” contains the full claimed dose set
Separate products administered sequentially	Could implicate method claims; preparation and package claims depend on product configuration
Fixed-dose combination tablets	Potentially covered only if the first phase lacks the claimed progestogenic activity and the second phase contains both activities

The critical formulation distinction is phase composition. The estrogen-dominant phase must not merely contain estrogen as the principal active. It is described as a phase comprising estrogenic activity, while the second phase must contain both estrogenic and progestogenic activity.

When did U.S. Patent 6,747,019 lose exclusivity?

The patent issued June 8, 2004. Its standard U.S. patent term would ordinarily run 20 years from the relevant nonprovisional or international filing date, not from the issue date. Public patent records identify the patent as an early-2000s pharmaceutical patent, making a 2020 expiration date consistent with the statutory term under 35 U.S.C. §154.

Event	Date
U.S. patent issued	June 8, 2004
Standard term endpoint	Approximately 2020
Current status	Expired by lapse of ordinary patent term, subject to official term calculations
Prospective U.S. blocking right	Generally unavailable after expiration

Patent expiration eliminates ordinary infringement liability for post-expiration conduct. It does not erase prior infringement claims, damages that accrued before expiration, or contractual restrictions in a separate license or settlement agreement.

What is the Orange Book status of the patent?

The relevant commercial product was an estradiol/norgestimate hormone-replacement regimen associated with the patented six-day alternating concept. Orange Book relevance depends on the specific NDA and whether the patent was listed against that NDA during the product’s commercial life.

An Orange Book listing would have affected ANDA applicants while the patent remained unexpired. A listed patent could support a Paragraph IV certification and potential Hatch-Waxman litigation. After expiration, the patent no longer provides a live patent barrier to an ANDA applicant, although historical listing information can remain visible in FDA records.

The Orange Book does not itself determine claim validity or infringement. It records patent information submitted by NDA holders and accepted under FDA listing rules. Patent scope remains a matter for the patent statute and courts. [1]

Were Paragraph IV challenges or generic litigation significant?

A Paragraph IV certification would have been relevant only before patent expiration. The supplied claim text does not establish the existence, timing, or outcome of a specific ANDA challenge, district-court action, or settlement agreement.

The principal litigation issues that would have arisen from a Paragraph IV challenge include:

Whether the accused product used the three-day/three-day sequence;
Whether the estrogen dose was equivalent to 1 mg/day of 17β-estradiol;
Whether the progestogen dose was equivalent to 90 μg/day of norgestimate;
Whether “relatively dominant” was definite and technically meaningful;
Whether the Markush alternatives were adequately supported and enabled;
Whether the package claims were infringed by an ANDA labeling design; and
Whether the claims were anticipated or rendered obvious by earlier cyclic HRT regimens.

Because the patent has expired, a new Paragraph IV challenge would generally have no commercial purpose against the expired patent. The more relevant current question is whether any later, unexpired patents cover a particular generic formulation, delivery system, labeling instruction, or manufacturing process.

How strong is the patent estate?

The patent estate appears strong at the level of regimen concept but limited as a current exclusivity asset.

Strength factor	Assessment
Core concept	Specific and commercially recognizable
Chemical breadth	Broad because of activity-equivalence language and Markush lists
Dosage precision	Moderately strong, centered on 1 mg estradiol and 90 μg norgestimate-equivalent activity
Package coverage	Meaningful for branded blister-pack configurations
Method coverage	Useful where administration follows the patented sequence
Claim construction risk	Significant because of “about,” “equivalent,” “relatively dominant,” and typographical errors
Obviousness risk	Potentially material if prior art disclosed cyclic estrogen/progestogen HRT
Current enforceability	Expired ordinary term removes prospective exclusionary power

The patent’s value was likely concentrated in coordinating the product, package, and method claims around one commercial regimen. That structure can increase enforcement leverage during the patent term because a challenger must address multiple infringement theories.

How does this patent compare with competing HRT patent strategies?

The patent uses regimen protection. Other HRT patent strategies typically protect one of four different assets:

Strategy	Typical protected subject matter	Relevance to Patent 6,747,019
Active-ingredient patent	New estrogen, progestogen, or combination	6,747,019 does not claim a new active ingredient
Formulation patent	Release profile, excipient matrix, stability, or dosage form	The patent has limited formulation detail
Regimen patent	Sequence, cycle length, dose, and treatment schedule	This is the patent’s principal strategy
Manufacturing patent	Synthesis, purification, crystallization, or scale-up	Not the apparent focus of the supplied claims
Labeling or method patent	Specific treatment population or administration instruction	Claims 13 through 18 use this route

The patent therefore would not necessarily block every estradiol/norgestimate product. It targeted a defined phased regimen and its packaged implementation.

What generic launch risks existed?

Before expiration, a generic launch would have faced several possible barriers:

A product claim challenge based on the exact dose sequence.
A package claim challenge based on blister-pack organization.
A method claim challenge based on proposed labeling.
Equivalence disputes involving estrogenic and progestogenic activity.
Injunction risk under Hatch-Waxman litigation.
Separate formulation or manufacturing patents not identified in the supplied claims.

After expiration, the principal remaining risks are commercial and regulatory rather than patent-term barriers. A generic sponsor would still need to establish bioequivalence, satisfy FDA labeling requirements, address discontinued-product issues, and avoid any later unexpired patents associated with the specific formulation or manufacturing process. [2]

What licensing and settlement issues should be reviewed?

The claims alone do not establish licensing transactions or settlement agreements. A complete commercial freedom-to-operate review would distinguish:

Patent licenses;
Trademark licenses;
Supply agreements;
Co-promotion arrangements;
ANDA litigation settlements;
Authorized-generic agreements; and
Transfer or assignment records.

A patent assignment does not prove a license, and an Orange Book listing does not prove litigation. Those documents must be assessed separately from the issued claims and prosecution history.

Key Takeaways

U.S. Patent 6,747,019 claims a three-day estrogen-dominant phase followed by a three-day phase combining estrogen and norgestimate-equivalent progestogenic activity.
The central dosage levels are approximately 1 mg/day of 17β-estradiol and 90 μg/day of norgestimate.
Claims cover preparations, packages, oral tablets, and treatment methods.
Claims 19 through 24 are the most product-specific because they expressly recite estradiol and norgestimate quantities.
“About,” “equivalent,” and “relatively dominant” create claim-construction and infringement issues.
The patent’s standard term appears to have ended in approximately 2020.
The patent no longer provides a prospective U.S. patent barrier if the ordinary expiration calculation applies.
Current generic risk is more likely to arise from later formulation, manufacturing, labeling, or product-specific patents than from Patent 6,747,019 itself.
Historical Paragraph IV activity, litigation, and settlements cannot be inferred from the claim text alone.

FAQs

What drug product was associated with U.S. Patent 6,747,019?

The claim structure corresponds to an estradiol/norgestimate hormone-replacement regimen using alternating estrogen-only and estradiol-plus-norgestimate phases. Product identification should be confirmed against the relevant FDA NDA and historical labeling records.

Does Patent 6,747,019 cover all estradiol and progestogen hormone-replacement products?

No. The patent requires a particular alternating phase structure, dose relationship, and activity profile. Continuous-combination and other sequential regimens may fall outside the claims.

Can a generic use estradiol and norgestimate after the patent expired?

The expired patent generally does not prevent use of those active ingredients in the United States. A generic sponsor must still evaluate other unexpired patents, FDA requirements, labeling, formulation, and manufacturing constraints.

Are the Markush progestogen alternatives automatically covered?

No. A listed alternative must satisfy the other claim limitations, including the phase sequence, estrogenic activity, progestogenic activity, and applicable receptor-profile requirements.

Can a package claim be infringed even if the tablets are chemically old?

Yes. A package claim can cover the arrangement and sequencing of known tablets. Chemical novelty is not required if the claimed package combination remains within the scope of a valid, unexpired claim.

References

U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book. https://www.fda.gov
U.S. Food and Drug Administration. (2024). Code of Federal Regulations, Title 21, Part 314: Applications for FDA approval to market a new drug. https://www.ecfr.gov
United States Patent and Trademark Office. (2004). U.S. Patent No. 6,747,019, pharmaceutical preparation for hormone replacement therapy. https://patents.google.com
United States Code. (2024). 35 U.S.C. § 154: Contents and term of patent; provisional rights. https://uscode.house.gov

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Argentina	029159	⤷ Start Trial
Australia	3412300	⤷ Start Trial
Brazil	0010968	⤷ Start Trial
Canada	2267743	⤷ Start Trial
China	1200747	⤷ Start Trial
China	1358104	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 6,747,019

Summary for Patent: 6,747,019