US Drug Patent RE39861: Claim Scope, Expiration, Orange Book Status and Generic Risk

US Patent RE39861 protected the extended-cycle oral contraceptive regimen marketed as Seasonale: 84 consecutive days of combined estrogen and progestin followed by a 7-day placebo interval, producing four scheduled withdrawal bleeds per year. The patent covered method-of-use and kit configurations rather than a new chemical entity. Its statutory term expired on June 20, 2017, eliminating the patent as a current barrier to generic entry.

What drug regimen did US Patent RE39861 protect?

RE39861 covered a monophasic extended-cycle contraceptive regimen administered to a premenopausal woman.

Claim element	Scope
Therapeutic category	Combined oral hormonal contraception
Estrogen	Generally ethinyl estradiol, with a claimed equivalent range
Progestin	Norethindrone acetate or, in claim 12, levonorgestrel
Active treatment period	Broadly amended to 84 consecutive days
Hormone-free period	Five to eight days in the principal narrowed claim; the commercial regimen used seven placebo days
Annual cycle	Four scheduled menstrual periods or withdrawal bleeds
Packaging	Active tablets and placebo tablets packaged in a kit
Patient population	Premenopausal females
Administration	Oral, monophasic administration
Required result	Reduction to four menstrual periods per year after at least one year

The practical commercial embodiment was Seasonale, which contained 30 mcg of ethinyl estradiol and 0.15 mg of levonorgestrel for 84 days, followed by seven placebo tablets. The FDA-approved Seasonale labeling describes the same 91-day regimen and four scheduled withdrawal bleeding episodes per year.[2]

How should the RE39861 claims be construed?

The claims combine regimen, dosage, duration, packaging and clinical-result limitations. A product would not fall within the principal claim merely because it contained the same hormones. It would need to be used in the claimed extended-cycle manner.

Claim 1: principal method claim

Claim 1 requires all of the following:

A premenopausal female.
Oral administration.
A monophasic estrogen-progestin combination.
Administration for 84 consecutive days after the claim amendments.
Daily doses corresponding to approximately 30 mcg of ethinyl estradiol and 0.25 to 1.5 mg of norethindrone acetate, as reflected in the amended claim language.
A subsequent placebo period of five to eight days.
Packaging of the active and placebo products together as a kit.
Reduction of menstrual periods to four per year when practiced for at least one year.

The claim is narrower than a general claim to extended-cycle contraception. It requires a specific schedule and a four-period annual outcome.

Claims 2 through 6: preferred norethindrone acetate embodiment

Claims 2 through 6 progressively narrow the regimen to:

10 to 20 mcg of ethinyl estradiol;
0.25 to 1.5 mg of norethindrone acetate;
at least 80 consecutive days of active treatment;
ethinyl estradiol as the estrogen; and
norethindrone acetate as the progestin.

These claims are directed primarily to low-dose ethinyl estradiol/norethindrone acetate regimens rather than the 30 mcg ethinyl estradiol/levonorgestrel composition used in Seasonale.

Claims 7 through 10: alternative dependent limitations

Claims 7 through 10 separately add:

the 0.25 to 1.5 mg progestin range;
at least 80 consecutive days;
ethinyl estradiol; and
norethindrone acetate.

They preserve the core claim 1 regimen while adding individual limitations instead of requiring the full claim 2-to-6 sequence.

Claim 11: estrogen limitation

Claim 11 limits the estrogen dose to up to 30 mcg of ethinyl estradiol. This limitation is commercially important because Seasonale used 30 mcg of ethinyl estradiol.

Claim 12: levonorgestrel alternative

Claim 12 depends from claim 9 and substitutes levonorgestrel for norethindrone acetate. Its scope is the closest fit to a Seasonale-type regimen:

extended-cycle administration;
ethinyl estradiol;
levonorgestrel;
placebo interval; and
four annual bleeding episodes.

The claim does not require the exact Seasonale strength of 0.15 mg levonorgestrel in the text supplied, but the broader limitations of claim 1 still apply.

What amendments narrowed the RE39861 claims?

The supplied text shows original and amended language. The important amendments narrowed the patent from a broad extended-cycle concept to a more specific regimen.

Original or broader language	Amended or operative language
60 to 110 days	84 consecutive days
5 to 35 mcg ethinyl estradiol	30 mcg
0.025 to 10 mg progestin	0.25 to 1.5 mg norethindrone acetate
Non-administration of placebo	Administration of placebo
Three to 10 days	Five to eight days
General extended-cycle use	Four menstrual periods per year after at least one year

The amendments reduce literal infringement risk for products using materially different dosing schedules, hormone-free intervals or delivery formats. They also make the patent more dependent on the commercial regimen rather than on the general concept of reducing menstruation.

What patent protected Seasonale and when did RE39861 expire?

RE39861 was a reissue patent based on the earlier extended-cycle contraceptive patent family. The relevant term was controlled by the original patent term and could not be extended merely because the reissue issued later.

Event	Date
Earliest priority date	June 20, 1996
Original nonprovisional filing	June 20, 1997
Original patent issuance	February 22, 2000
Reissue patent issuance	December 4, 2007
Statutory patent expiration	June 20, 2017
Current enforceability	Expired

The reissue did not restart the patent term. Any patent-term adjustment reflected in the USPTO record would be assessed against the original patent term, not the 2007 reissue date.[1]

What was the Orange Book status of RE39861?

RE39861 was associated with the Seasonale NDA and historically appeared in the FDA Orange Book patent framework for the product. The Orange Book listing was relevant to ANDA applicants because a generic applicant had to address listed patents through certification under the Hatch-Waxman statute.[3]

The patent’s commercial relevance was greatest before 2017. After expiration:

a Paragraph III certification could no longer defer approval based on an unexpired patent;
a Paragraph IV challenge to RE39861 ceased to create a meaningful ongoing patent-exclusion risk;
the FDA could approve ANDAs for equivalent extended-cycle contraceptive products if the applicants met regulatory requirements; and
the expired patent no longer supported an injunction against a current generic launch.

Orange Book listing and patent enforceability are separate issues. A historical listing does not preserve exclusion after expiration.

When did Seasonale lose regulatory and patent exclusivity?

Seasonale had two distinct forms of protection.

Protection	Relevant timing	Effect
FDA three-year exclusivity	Through approximately September 5, 2006	Restricted certain abbreviated applications relying on new clinical investigations
RE39861 patent term	Through June 20, 2017	Restricted infringing use, sale or marketing within the patent scope
Post-expiration period	From June 21, 2017	No remaining exclusion from RE39861

Seasonale was approved by FDA on September 5, 2003. Its three-year regulatory exclusivity was separate from the patent and did not extend the patent term.[2][3]

What Paragraph IV challenges affected the patent?

The commercial patent dispute centered on generic versions of Seasonale and related extended-cycle oral contraceptives. An ANDA applicant seeking approval before the June 2017 expiration would have had to address the listed patent through a Paragraph IV certification or wait for expiration.

The relevant litigation risk had three components:

Infringement: whether the generic label induced use of the 84-day active/7-day placebo regimen.
Validity: whether the claims were obvious or anticipated in view of conventional 21-day oral contraceptive regimens and prior extended-cycle proposals.
Enforceability: whether prosecution and reissue conduct created an inequitable-conduct or other enforceability defense.

A generic applicant could reduce exposure by using a different regimen, avoiding a claimed kit configuration, or launching after expiration. For a drug labeled for the same Seasonale regimen, the method-of-use claims created greater risk than composition claims would have created because the patent focused on administration instructions.

The patent expired in 2017. Any pre-expiration Paragraph IV litigation no longer affects current launch freedom for the RE39861 claims.

Which companies challenged the Seasonale patent estate?

Seasonale was associated with Duramed Pharmaceuticals and later commercialized within the Barr Pharmaceuticals and Teva organization. Generic competition came from companies developing levonorgestrel/ethinyl estradiol extended-cycle products, including major ANDA manufacturers active in the U.S. oral contraceptive market.

The relevant competitive structure was:

Company or group	Role
Duramed Pharmaceuticals	Original product sponsor and patent holder associated with the Seasonale product
Barr Pharmaceuticals	Parent or commercial affiliate before the Teva acquisition
Teva Pharmaceuticals	Later owner or commercial participant in the product portfolio
Generic ANDA sponsors	Developers of equivalent levonorgestrel/ethinyl estradiol products
FDA	NDA and ANDA regulator; Orange Book administrator

The patent estate was not a biologic estate and did not create biosimilar litigation. Any competing product would proceed through the ANDA pathway for a small-molecule oral contraceptive, not through the 351(k) biosimilar pathway.

How strong was the RE39861 patent estate?

RE39861 had moderate historical strength and low current strength because it expired.

Historical strengths

The 84-day active-treatment schedule was commercially specific.
The four-period annual result tied the method to a clear clinical objective.
Claim 12 reached a levonorgestrel embodiment corresponding to Seasonale.
The kit limitation supported a packaged commercial product.
The method claims could be asserted against labeled use, not only against the tablet composition.

Historical weaknesses

Extended-cycle contraception was conceptually close to known oral contraceptive regimens.
The active ingredients were established contraceptive hormones.
The claims relied on a known dosage form and known administration route.
Kit and placebo packaging limitations could be designed around.
Claims directed to a treatment schedule can be vulnerable to obviousness arguments based on routine modification of the conventional 21-day cycle.
A generic could argue that the commercial label did not necessarily satisfy every patient-specific result limitation, particularly the requirement to reduce menstrual periods to four per year after at least one year.

Current strength

Current enforceability is zero because the patent term ended in 2017. The remaining value is historical, freedom-to-operate context, prosecution history and prior-art evidence for later extended-cycle contraceptive patents.

What formulations and delivery systems did RE39861 cover?

The patent primarily covered a packaged oral tablet regimen. It did not broadly claim:

transdermal patches;
vaginal rings;
injectable contraception;
implants;
intrauterine systems;
depot formulations; or
sustained-release delivery technologies.

The kit limitation could cover a package containing active hormone tablets and placebo tablets. A product using a different packaging structure might avoid literal infringement, although induced-infringement analysis would depend on the label and commercial instructions.

RE39861 also did not create broad composition-of-matter protection for ethinyl estradiol, norethindrone acetate or levonorgestrel. Those active ingredients were known compounds. The patent value arose from the regimen and packaging combination.

How does RE39861 compare with later extended-cycle contraceptive patents?

RE39861 should be separated from later patents covering modified hormone-free intervals, low-dose estrogen during the nominal placebo period, continuous dosing, or different progestin combinations.

Patent category	Typical protected subject matter	Relationship to RE39861
Extended-cycle regimen	84 active days plus placebo interval	Core RE39861 subject
Continuous regimen	No scheduled hormone-free interval	Generally outside the placebo requirement
Four-day or shortened placebo regimen	Reduced hormone-free interval	May avoid the five-to-eight-day limitation
Estrogen bridge regimen	Low-dose estrogen during the final days	Different from placebo administration
Low-dose norethindrone regimen	Specific ethinyl estradiol/norethindrone strengths	Relevant to claims 2-10
Levonorgestrel extended cycle	30 mcg ethinyl estradiol plus levonorgestrel	Closest to claim 12 and Seasonale
New delivery system	Ring, patch, implant or IUD	Usually outside the oral-kit limitations

Later products such as Seasonique and Amethia introduced regimen variations, including estrogen-containing tablets during part of the interval rather than a conventional placebo-only interval. Those products required separate patent and regulatory analysis.

What generic entry risks existed before expiration?

Before June 20, 2017, a generic Seasonale-type product faced several possible launch scenarios.

Paragraph III launch

The applicant could certify that RE39861 would be respected until expiration and launch after the patent term ended. This was the lowest litigation-risk route but delayed market entry.

Paragraph IV launch

The applicant could allege that RE39861 was invalid, unenforceable or not infringed. That route created potential litigation and, if timely sued, an FDA approval stay of up to 30 months under Hatch-Waxman.

Design-around launch

A competitor could attempt to avoid one or more claim limitations by:

using a hormone-free interval outside five to eight days;
using active treatment for fewer than 80 or 84 days;
omitting the kit format;
using a different estrogen or progestin;
using a continuous regimen; or
labeling a different dosing schedule.

The risk was highest for a product that reproduced the 84-day active/7-day placebo Seasonale label.

What licensing and settlement issues affected the estate?

The commercial product passed through the Duramed, Barr and Teva corporate chain. Licensing and corporate ownership arrangements were commercially relevant because the patent holder, NDA holder, authorized generic sponsor and litigation entity could differ over time.

No post-expiration settlement can preserve RE39861 exclusivity. A pre-expiration settlement could have included:

an agreed generic entry date;
a license to the patent;
a no-challenge provision;
supply or authorized-generic terms; or
restrictions on the generic label.

The patent’s expiration makes any historical settlement commercially important only for reconstructing the timing of generic entry and market competition.

What is the current competitive landscape for Seasonale-type products?

The market is a mature small-molecule contraceptive market with multiple generic oral contraceptives and alternative hormonal delivery systems. Current competition is driven by:

price and formulary status;
adherence and convenience;
bleeding-profile preferences;
hormone dose;
availability of generic levonorgestrel/ethinyl estradiol products;
extended-cycle versus monthly regimens; and
physician and patient acceptance.

RE39861 no longer supports a premium based on exclusivity. Commercial differentiation must come from branding, supply reliability, formulation, tolerability, dosing convenience or separate unexpired patents.

What revenue exposure did RE39861 create?

The patent protected the commercial regimen underlying a branded extended-cycle oral contraceptive during the period when Seasonale had limited direct generic competition. Revenue exposure was concentrated in:

the branded Seasonale product;
authorized-generic economics;
extended-cycle oral contraceptive prescriptions;
related products using similar levonorgestrel/ethinyl estradiol regimens; and
potential follow-on products using different hormone-free intervals.

After 2017, the key financial event was loss of patent-based pricing power. The effect depended on the number of approved ANDA competitors, payer substitution and the extent to which physicians treated other oral contraceptives as substitutes.

Key Takeaways

RE39861 protected an extended-cycle oral contraceptive method, not the underlying hormones.
The core regimen was 84 active days followed by approximately seven placebo days.
Claim 12 is the closest claim to the Seasonale formulation because it covers ethinyl estradiol with levonorgestrel.
The claims require a method of use and, in claim 1, a kit containing active and placebo products.
The patent was historically relevant to Paragraph IV certification and Seasonale generic litigation.
FDA approval of Seasonale occurred on September 5, 2003, with three-year regulatory exclusivity ending in 2006.
The RE39861 patent term expired on June 20, 2017.
RE39861 presents no current generic or biosimilar barrier.
Later extended-cycle products require separate review because different placebo intervals, estrogen-bridge regimens and delivery systems may fall outside RE39861.
The patent’s residual value is historical: claim construction, prosecution history, prior-art analysis and reconstruction of generic-entry timing.

FAQs About US Patent RE39861

Does RE39861 cover Seasonale itself?

Yes. The patent claims encompass the Seasonale-type method of administering ethinyl estradiol and levonorgestrel for 84 days followed by placebo tablets, producing four scheduled withdrawal bleeding periods per year.

Does RE39861 cover Seasonique?

Not necessarily. Seasonique uses a different regimen involving low-dose ethinyl estradiol tablets during the final interval rather than a conventional placebo-only interval. Its patent and label scope must be analyzed separately.

Is RE39861 still enforceable against generic birth-control products?

No. The patent expired on June 20, 2017, so it cannot currently block a generic product on the basis of its patent claims.

Does the patent claim the 30 mcg ethinyl estradiol and 0.15 mg levonorgestrel composition?

No broad composition claim is reflected in the supplied claims. The patent claims use of the hormones in a defined extended-cycle regimen and, for claim 1, a packaged kit.

Can a generic avoid RE39861 by selling the tablets without placebo tablets?

Before expiration, omitting the placebo component could have supported a design-around argument because the claims require a placebo period and claim 1 expressly requires a kit containing the combination and placebo. That issue has no current significance because the patent has expired.

Is a biosimilar application required for a Seasonale generic?

No. Seasonale is a small-molecule oral contraceptive. A competing product would generally use the ANDA pathway, not the FDA biosimilar pathway under section 351(k).

References

United States Patent and Trademark Office. (2007). Extended regimen oral contraceptive, U.S. Patent No. RE39,861.
U.S. Food and Drug Administration. (2003). Seasonale levonorgestrel and ethinyl estradiol tablets: Prescribing information.
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations, commonly known as the Orange Book.### Sources:

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	216241	⤷ Start Trial
Canada	2256977	⤷ Start Trial
Canada	2596416	⤷ Start Trial
Germany	69804918	⤷ Start Trial
Denmark	0911029	⤷ Start Trial
European Patent Office	0911029	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Summary for Patent: RE39861