Details for Patent: 11,033,551

Which drugs does patent 11,033,551 protect, and when does it expire?

Patent 11,033,551 protects MYFEMBREE and is included in one NDA.

This patent has eighty-one patent family members in twenty-seven countries.

Summary for Patent: 11,033,551

Title:	Methods of treating uterine fibroids
Abstract:	Methods for treating uterine fibroids, endometriosis, adenomyosis, or heavy menstrual bleeding in a subject, which include administering to the subject from 10 mg to 60 mg per day of N-(4-(1-(2,6-difluorobenzyl)-5-((dimethylamino)methyl)-3-(6-methoxy-3-pyridazinyl)-2,4-dioxo-1,2,3,4-tetrahydrothieno[2,3-d]pyrimidin-6-yl)phenyl)-N′-methoxyurea, and from 0.01 mg to 5 mg per day of a hormone replacement medicament. The present disclosure has methods for reducing menstrual bleeding in a subject, reducing bone mineral density loss in a subject caused by administering a GnRH antagonist to the subject, suppressing sex hormones in a subject, reducing vasomotor symptoms or hot flashes in a subject, and reducing symptoms of decreased libido in a subject having uterine fibroids, endometriosis, or adenomyosis. Further provided are methods of maintaining blood glucose profile, maintaining lipid profile, and/or maintaining bone mineral density in a pre-menopausal woman being treated for one or more conditions or symptoms of endometriosis, adenomyosis, uterine fibroids, or heavy menstrual bleeding; and methods of contraception and treating infertility.
Inventor(s):	Brendan Mark JOHNSON, Lynn Seely, Paul N. MUDD, Jr., Susan Wollowitz, Mark Hibberd, Masataka TANIMOTO, Vijaykumar Reddy RAJASEKHAR, Mayukh Vasant SUKHATME
Assignee:	Takeda Pharmaceutical Co Ltd , Sumitomo Pharma Co Ltd , Roivant Sciences Inc
Application Number:	US16/370,299
Patent Claim Types: see list of patent claims	Use; Dosage form;

# United States Patent 11,033,551: Scope, Claim Construction, Expiration and Myfembree Patent Landscape

U.S. Patent No. 11,033,551 protects once-daily oral treatment of uterine fibroids and fibroid-associated heavy menstrual bleeding with relugolix, estradiol, and norethindrone acetate. Its commercial relevance is principally tied to Myfembree, the fixed-dose relugolix combination marketed by Myovant Sciences and AbbVie. The patent is method-of-use focused. It does not broadly claim relugolix, estradiol, norethindrone acetate, or every relugolix combination.

The claims require a specific therapeutic regimen, a pre-menopausal patient, ovarian suppression demonstrated by prevention of ovulation, and preservation of bone mineral density within a defined range. Independent claims 1, 6, and 20 establish three related but materially different infringement pathways.

What drug and product are covered by U.S. Patent 11,033,551?

The active pharmaceutical ingredient identified by its chemical name in the claims is relugolix. The claimed combination corresponds to:

Component	Claimed amount	Commercial relevance
Relugolix	About 40 mg	Gonadotropin-releasing hormone receptor antagonist
Estradiol	About 1.0 mg	Hormonal add-back therapy
Norethindrone acetate	About 0.5 mg	Progestin add-back therapy

Myfembree contains relugolix 40 mg, estradiol 1 mg, and norethindrone acetate 0.5 mg in a once-daily tablet. FDA approved Myfembree on May 28, 2021, for the management of heavy menstrual bleeding associated with uterine fibroids in pre-menopausal women. FDA later approved the product for moderate-to-severe pain associated with endometriosis. The fibroid indication is the principal indication implicated by the claims analyzed here. [1]

What are the independent claims of U.S. Patent 11,033,551?

Claim 1: Treatment of uterine fibroids

Claim 1 requires all of the following:

1. A method of treating uterine fibroids.
2. A pre-menopausal woman in need of treatment.
3. Once-daily oral administration.
4. Approximately 40 mg of relugolix, or an equivalent amount of a pharmaceutically acceptable salt.
5. Approximately 1.0 mg estradiol.
6. Approximately 0.5 mg norethindrone acetate.
7. Suppression of ovarian estrogen production, demonstrated by prevention of ovulation.
8. Bone mineral density during treatment within plus or minus 3% of baseline.

The claim is therefore narrower than a conventional composition claim. A product may contain the same active ingredients but fall outside claim 1 if the administration schedule, patient population, ovulation result, or bone-mineral-density limitation is absent.

Claim 6: Heavy menstrual bleeding associated with fibroids

Claim 6 uses the same core regimen and physiological limitations as claim 1 but requires treatment of heavy menstrual bleeding associated with uterine fibroids.

This claim is commercially important because it tracks the principal FDA-approved Myfembree fibroid indication. A generic applicant seeking approval for the same indication would face a direct method-of-use patent issue if the proposed labeling, prescribing information, or product instructions read on the claimed regimen.

Claim 20: Alternative wording for the combination and minimum treatment duration

Claim 20 covers treatment of fibroid-associated heavy menstrual bleeding using the same relugolix regimen, with treatment for at least four consecutive weeks. It also recites approximately 1.0 mg estradiol and approximately 0.5 mg norethindrone acetate.

The supplied text of claim 20 contains a drafting anomaly: it states “about 1.0 mg of estradiol or a corresponding amount of norethindrone acetate; and about 0.5 mg of norethindrone acetate.” Read literally, that language creates an internal inconsistency because norethindrone acetate is recited both as an alternative to estradiol and as a separately required 0.5 mg component. The issued patent, prosecution history, certificate of correction, and claim construction record would control the legal treatment of this wording. A definitive infringement analysis should not rely on the supplied transcription alone.

How do the dependent claims expand the patent scope?

The dependent claims add clinical outcomes, patient subgroups, dosing formats, and duration limits.

Claims	Added limitation	Scope effect
2, 7	Bone mineral density within plus or minus 2%	Narrower preservation endpoint
3, 8	Serum estradiol between 20 and 50 pg/mL	Adds pharmacodynamic exposure requirement
4, 16	Reduction in fibroid number or size	Adds anatomical efficacy result
5, 9	Patient is peri-menopausal	Narrows the pre-menopausal population
10	MBL below 80 mL, or at least 50% reduction	Adds quantified bleeding endpoint
11-13	Reduced pain, including pelvic pain and dysmenorrhea	Adds symptom-based outcomes
14	Improvement in specified clinical and quality-of-life symptoms	Broadens the listed outcome categories
15	Amenorrhea	Adds a menstrual outcome
17	Reduced uterine volume	Adds an imaging or anatomical endpoint
18	Median FSH reduced 2.1- to 4.1-fold	Adds a quantified endocrine endpoint
19	Treatment for at least 24 consecutive weeks	Adds a longer duration requirement
21-26	Single dosage form or separate co-administered dosage forms	Covers both fixed-dose and multi-product administration

Claims 21 through 26 are strategically important. They prevent a narrow design-around based solely on tablet presentation. The claims reach both:

• A single dosage form containing the combination; and
• Separate dosage forms administered together.

The patent therefore does not depend entirely on Myfembree being a single tablet. A relugolix product administered with separately supplied estradiol and norethindrone acetate could still implicate the relevant claims if all other limitations are satisfied.

What is the legal scope of the bone-mineral-density limitation?

The bone-mineral-density limitation is a central claim element, not an intended-use statement.

Claims 1, 6, and 20 require bone mineral density during treatment to remain within plus or minus 3% of baseline. Claims 2 and 7 narrow the range to plus or minus 2%.

A claimant would generally need to establish that the treated patient or patient population satisfies this limitation. The limitation may create proof issues in an ANDA case because the generic applicant’s product label may not expressly state that bone mineral density remains within the claimed range. The patentee could argue that the result is an inherent property of practicing the claimed regimen, but inherency requires that the result necessarily occur, not merely that it be likely or expected.

The limitation also creates potential validity questions:

• Whether the bone-mineral-density result was adequately described in the specification.
• Whether the result is inherent in the disclosed regimen.
• Whether the claim is enabled across the full scope of pre-menopausal women.
• Whether the limitation distinguishes the claimed treatment from prior relugolix regimens with add-back therapy.

Claims with the plus-or-minus 2% limitation have a narrower literal scope but may be more difficult to invalidate for lack of numerical specificity if the specification and clinical data support the range.

How does ovarian suppression affect infringement?

The claims require suppression of ovarian estrogen production “as demonstrated by prevention of ovulation.”

This limitation has two related components:

1. The treatment must suppress ovarian estrogen production.
2. Prevention of ovulation must demonstrate that suppression.

The language is narrower than a claim requiring only reduced estradiol levels. A regimen that lowers estrogen but permits ovulation may not satisfy the limitation. Conversely, a generic regimen that produces the same pharmacodynamic effect may satisfy it even if the label does not use identical wording.

Claim 3 and claim 8 add a serum estradiol range of 20 to 50 pg/mL between daily doses. This range is not required by the independent claims. It creates a separate, narrower infringement theory that may depend on pharmacokinetic data, clinical testing, or the product’s known dose-response profile.

What formulations are protected by U.S. Patent 11,033,551?

The patent protects the therapeutic combination more than a particular formulation architecture.

Single-tablet formulations

Claims 21 and 23 cover administration as a single dosage form. A fixed-dose tablet containing relugolix, estradiol, and norethindrone acetate is the clearest commercial embodiment.

Separate dosage forms

Claims 22 and 24 cover separate dosage forms that are co-administered. A relugolix tablet taken with separate estradiol and norethindrone acetate products could fall within these claims if the regimen satisfies the remaining limitations.

What the patent does not expressly claim

Based on the supplied claims, the patent does not expressly require:

• A particular excipient.
• A specific tablet coating.
• A dissolution profile.
• A specific polymorph.
• A crystalline form.
• A particular manufacturing process.
• A specific particle-size distribution.
• A particular packaging configuration.
• A specific fixed-dose tablet strength beyond the stated active amounts.

Those subject matters may be covered by separate formulation, composition, process, or solid-state patents.

When does U.S. Patent 11,033,551 expire?

The patent’s expected basic term is tied to its earliest effective nonprovisional or international filing date, subject to patent-term adjustment, terminal disclaimers, and any applicable patent-term extension.

Public patent records identify the patent family as relating to relugolix combination treatment and place the expected expiration in approximately March 2038. The precise enforceable date must be taken from the USPTO patent-term calculation and Orange Book listing rather than inferred solely from the issue date. The patent issued on June 15, 2021. [2]

The practical exclusivity timeline is:

Event	Date or period
Earliest family priority	2017-2018 period, based on the patent family
U.S. patent issuance	June 15, 2021
FDA approval of Myfembree for fibroid-associated HMB	May 28, 2021
Expected patent-term end	Approximately March 2038, subject to PTA and listing data
FDA three-year clinical exclusivity	Associated with the 2021 approval and no longer the principal barrier after 2024
Regulatory reference product period	Separate from patent expiration and governed by the ANDA pathway

The patent is therefore capable of extending branded protection well beyond the end of the initial FDA clinical-exclusivity period.

What is the Orange Book status of Myfembree?

Myfembree is an FDA-approved prescription drug product, and its relevant patents are evaluated through the FDA Orange Book framework. Orange Book-listed method-of-use patents can require a generic applicant to address the patent through a Paragraph IV certification or a section viii statement, depending on whether the proposed labeling includes the patented use. [3]

For a generic version that seeks the fibroid heavy-menstrual-bleeding indication, a section viii carve-out may be difficult if the patented use corresponds to the principal labeled indication. A generic applicant may instead need to:

• Certify that the patent has expired.
• Certify that the patent is not infringed, invalid, or unenforceable under Paragraph IV.
• Seek approval with a permissible labeling carve-out that excludes the protected method.

The availability of a section viii strategy depends on the exact Orange Book use code, FDA labeling, and whether the unpatented indications can support a commercially viable product.

Which companies are challenging Myfembree patent protection?

A definitive list of challengers requires current FDA Paragraph IV data, ANDA litigation filings, and Orange Book updates. The supplied claims identify no challenger, ANDA number, Paragraph IV certification, litigation docket, or settlement agreement.

The most likely commercial challenge would come from a generic applicant filing an ANDA for the 40 mg/1 mg/0.5 mg combination or for a relugolix product intended to be co-administered with estrogen and progestin add-back therapy. Such a challenge would likely target:

• Claim construction of the bone-mineral-density limitation.
• Inherency of ovulation prevention.
• Written description and enablement of numerical clinical endpoints.
• Obviousness over relugolix monotherapy and add-back therapy.
• The scope of claims 21-26 covering single and separate dosage forms.
• The ambiguity in claim 20, if that wording appears in the issued patent.

No biosimilar pathway is relevant. Relugolix is a small molecule, so a competitor would generally proceed through an ANDA or, for a new product with materially different clinical positioning, a 505(b)(2) application rather than a biosimilar application.

How strong is the patent estate for Myfembree?

U.S. Patent 11,033,551 is commercially meaningful but should be viewed as one layer of a broader product estate.

Strengths

• The claims track the labeled fibroid indication.
• The dose combination corresponds closely to the marketed product.
• The claims cover both a single dosage form and separate co-administration.
• The claims include clinically meaningful endpoints.
• The bone-mineral-density limitation addresses a known safety and tolerability issue associated with ovarian suppression.
• The patent can support a method-of-use infringement case against a generic product using substantially identical labeling.

Vulnerabilities

• The claims are highly fact-dependent.
• Bone-mineral-density results may be difficult to prove from labeling alone.
• Prevention of ovulation may require clinical or pharmacodynamic evidence.
• Numerical clinical limitations can create written-description, enablement, and indefiniteness disputes.
• Prior-art relugolix studies and hormonal add-back regimens may support obviousness arguments.
• Claim 20 requires careful review because of the apparent estradiol/norethindrone wording problem.
• A generic applicant may seek a labeling carve-out or challenge only the claims associated with the fibroid indication.

The estate is stronger against a copycat regimen using the same dosage, patient population, indication, and administration schedule than against a product with a materially different dose, treatment duration, or labeled indication.

What generic launch scenarios exist?

Scenario 1: Paragraph IV challenge with the fibroid indication

A generic applicant seeks approval for the same relugolix/estradiol/norethindrone regimen and certifies that the patent is invalid or not infringed. Litigation could trigger the Hatch-Waxman 30-month stay if statutory conditions are met. [4]

Scenario 2: Section viii carve-out

The applicant removes the patented fibroid indication but retains another approved use, if FDA determines that the remaining labeling is legally and commercially viable. This approach reduces method-of-use exposure but may limit market access.

Scenario 3: 505(b)(2) product with different dosing or add-back

A sponsor could develop a different relugolix dose, different estrogen or progestin regimen, or different treatment population. That may avoid literal infringement but would require separate regulatory and clinical support.

Scenario 4: Post-expiration launch

A generic or follow-on product launches after the enforceable patent term and any applicable pediatric exclusivity or patent-term adjustment. On the available family timeline, the key date is approximately 2038.

What patent litigation and settlement issues matter?

A litigation assessment should focus on the ANDA product’s proposed labeling and not only on its tablet composition. The central questions are:

1. Does the proposed label include treatment of fibroid-associated heavy menstrual bleeding?
2. Does it instruct once-daily administration of the claimed strengths?
3. Does it describe or necessarily produce ovulation prevention?
4. Does the applicant rely on the same add-back regimen?
5. Does the product use a single tablet or separate co-administered dosage forms?
6. Has the applicant made Paragraph IV certifications against the listed patents?
7. Has a settlement restricted launch timing, authorized entry, or imposed a license?

Settlements in this area can produce an agreed generic entry date before patent expiration, an authorized generic arrangement, or a license limited to particular indications. No settlement terms can be attributed to U.S. Patent 11,033,551 from the claim text alone.

How does U.S. Patent 11,033,551 compare with composition and formulation patents?

Patent category	Typical subject matter	Relevance to 11,033,551
Active-ingredient patent	Relugolix molecule or chemical class	Protects the compound itself
Combination-composition patent	Relugolix plus estradiol and norethindrone acetate	Protects product composition or dosage form
Formulation patent	Tablet, excipients, release, stability, or manufacturing	Protects product construction
Method-of-use patent	Treatment of fibroids or HMB using defined regimen	Primary category of U.S. 11,033,551
Manufacturing patent	Synthesis, purification, or solid form	Can create manufacturing and supply-chain barriers
Pediatric or regulatory exclusivity	FDA statutory exclusivity	Independent of patent validity

U.S. Patent 11,033,551 is most important as a clinical-use barrier. It may remain relevant even if a separate composition patent expires earlier, provided the method claims remain valid and enforceable.

Key Takeaways

• U.S. Patent 11,033,551 is a method-of-use patent centered on relugolix 40 mg, estradiol 1 mg, and norethindrone acetate 0.5 mg.
• The principal protected use is treatment of uterine fibroids and fibroid-associated heavy menstrual bleeding in pre-menopausal women.
• The independent claims require once-daily oral administration, prevention of ovulation, and bone mineral density within plus or minus 3% of baseline.
• Dependent claims add a tighter bone-density range, serum estradiol levels, reduced fibroid burden, reduced uterine volume, lower menstrual blood loss, pain reduction, amenorrhea, FSH reduction, and treatment duration.
• Claims 21-26 cover both single-tablet administration and separate co-administered dosage forms.
• The expected patent-term end is approximately March 2038, subject to USPTO patent-term adjustment and Orange Book data.
• Generic risk is highest for an ANDA using the same indication, dose, schedule, and add-back regimen.
• Biosimilar risk is irrelevant because relugolix is a small-molecule drug.
• Claim 20 requires special review because the supplied wording appears internally inconsistent.
• The patent is commercially strong against close copies but vulnerable to challenges involving inherency, obviousness, enablement, written description, numerical endpoints, and labeling carve-outs.

Frequently Asked Questions

Does U.S. Patent 11,033,551 protect Myfembree itself?

It protects methods of using the Myfembree-like relugolix combination for specified fibroid-related treatments. It is not, based on the supplied claims, a broad composition claim covering every physical form of Myfembree.

Can a generic avoid the patent by supplying separate tablets?

Not necessarily. Claims 22, 24, and 26 expressly cover separate dosage forms that are co-administered.

Does a different relugolix dose avoid the claims?

A materially different dose may avoid literal infringement of claims requiring about 40 mg, but the issue would depend on claim construction, equivalence, and the product’s complete regimen.

Are endometriosis uses covered by these claims?

The supplied claims are directed to uterine fibroids and heavy menstrual bleeding associated with uterine fibroids. They do not expressly claim endometriosis treatment.

Is bone-density preservation required for every patient?

The claims recite bone mineral density during treatment as a limitation. Whether infringement can be established patient-by-patient, through population data, or through inherency depends on the evidence and claim construction.

References

1. U.S. Food and Drug Administration. (2021). FDA approves Myfembree for heavy menstrual bleeding associated with uterine fibroids in pre-menopausal women.
2. United States Patent and Trademark Office. (2021). U.S. Patent No. 11,033,551, Methods of treating uterine fibroids.
3. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book.
4. U.S. Food and Drug Administration. (2024). ANDA submissions: Patent certification and suitability petitions.

Drugs Protected by US Patent 11,033,551

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Sumitomo Pharma Am	MYFEMBREE	estradiol; norethindrone acetate; relugolix	TABLET;ORAL	214846-001	May 26, 2021		RX	Yes	Yes	11,033,551					MANAGEMENT OF HEAVY MENSTRUAL BLEEDING ASSOCIATED WITH UTERINE LEIOMYOMAS (FIBROIDS) IN PREMENOPAUSAL WOMEN

International Family Members for US Patent 11,033,551

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Argentina	109759
Argentina	109762
Argentina	110636