United States Patent 10,927,142: Ibrexafungerp Citrate Patent Scope, Claims, Expiration and Generic Risk

US 10,927,142 protects crystalline citrate salt forms of ibrexafungerp, the triterpenoid glucan synthase inhibitor marketed as Brexafemme. The patent is directed principally to solid-state forms, especially Type A ibrexafungerp citrate, and to injectable compositions and intravenous treatment of invasive Candida and Aspergillus infections. It does not broadly claim ibrexafungerp as a molecule.

The patent’s commercial importance depends on whether an ibrexafungerp product uses the claimed citrate salt or converts to one of the claimed crystal forms during manufacture, storage, or formulation. The claims create a substantial formulation and intravenous-product barrier, but they leave potential design-around routes through a different salt, amorphous material, nonclaimed polymorph, or chemically distinct formulation.

What drug and active ingredient does US 10,927,142 cover?

US 10,927,142 covers ibrexafungerp citrate, also known as SCY-078 citrate. Ibrexafungerp inhibits fungal glucan synthase and is active against Candida species, including azole-resistant strains, as well as certain Aspergillus species.

Item	Information
Patent	US 10,927,142 B2
Patent subject	Ibrexafungerp citrate crystalline forms and pharmaceutical uses
Patent holder	SCYNEXIS, Inc.
Drug	Ibrexafungerp citrate
Brand	Brexafemme
Therapeutic class	Triterpenoid glucan synthase inhibitor
Approved dosage form	Oral tablets
FDA approval	June 1, 2021
Approved indication	Vulvovaginal candidiasis
Claimed additional use	Injectable treatment of Candida and Aspergillus infections
Patent type	Solid-state, formulation and method-of-treatment patent
Nominal patent expiration	February 25, 2035

The claims provided identify the active pharmaceutical ingredient as “compound 1” rather than using the nonproprietary name. The claimed material corresponds to ibrexafungerp citrate.

What patents protect ibrexafungerp citrate?

The patent protects ten identified citrate crystal forms:

Type A
Type B
Type E
Type F
Type M
Type N
Type O
Type Q
Type R
Type S

Claim 1 covers a citrate salt of compound 1 containing at least one of those forms. Claims 2 and 3 narrow the protection to Type A and specified kinetic-solubility performance.

The patent therefore has two principal technical layers:

Structural solid-form protection based on XRPD characteristics.
Functional protection based on solubility properties for Type A.

The patent does not require all ten forms to be present. A product containing one claimed form can fall within claim 1 if the XRPD data satisfy the claimed peak limitations.

How many patents cover ibrexafungerp and Brexafemme?

The key US patent estate includes patents directed to the ibrexafungerp molecule, compositions, solid forms and treatment methods. US 10,927,142 is one of the later and more commercially targeted members because it addresses ibrexafungerp citrate forms suitable for pharmaceutical development and injectable use.

Patent category	Commercial role
Compound patents	Protect ibrexafungerp and related glucan synthase inhibitors
Composition patents	Cover pharmaceutical dosage forms and carriers
Solid-form patents	Protect citrate polymorphs and crystalline materials
Method-of-use patents	Cover treatment of fungal infections
Manufacturing patents	May restrict salt formation, crystallization and purification processes

The exact number of Orange Book-listed patents can change as patents issue, expire, are delisted, or receive pediatric extensions. The relevant point for generic planning is that US 10,927,142 is narrower than a basic compound patent but can block a generic using the same citrate solid form.

What does claim 1 of US 10,927,142 cover?

Claim 1 is a product claim. It covers a citrate salt of compound 1 comprising at least one of the ten specified crystal forms.

The claim uses XRPD peak positions as defining technical limitations. For example, Type A is identified by peaks including:

d-spacings of 11.86, 7.70, 7.09, 6.71, 5.90 and 5.29 Å; or
2-theta peaks of 7.45, 11.49, 12.49, 13.19, 15.02 and 16.75 degrees.

The other forms have separate peak signatures. A crystalline ibrexafungerp citrate sample would be evaluated against those signatures using powder X-ray diffraction.

Claim 1 infringement issues

Claim 1 raises several technical and legal questions:

Whether “comprises at least one” captures mixtures containing a claimed form.
Whether the listed XRPD peaks must all be present.
What degree of peak-position variation is permitted.
Whether preferred orientation, hydration, solvates or impurities alter the analysis.
Whether a sample that converts into a claimed form during storage infringes.
Whether a manufacturing intermediate, rather than the marketed product, contains the claimed form.

Because the claim is open-ended, the presence of an additional unclaimed polymorph may not avoid infringement if a claimed form is also present.

What does claim 2 protect?

Claim 2 narrows claim 1 to a citrate salt consisting essentially of Type A citrate crystal form.

“Consisting essentially of” generally excludes materials that materially alter the basic and novel characteristics of the claimed composition, while allowing some incidental components or impurities. The construction will depend on the specification and evidence concerning what affects the Type A crystal form.

Type A is commercially relevant because claim 3 links it to kinetic-solubility specifications in physiologically relevant media.

What does claim 3 protect?

Claim 3 requires Type A citrate crystal form and at least one specified kinetic-solubility result. The listed conditions include:

Test medium	Time point	Required solubility
Dextrose buffer, pH 5.5	4 hours	At least 4 mg/mL
Dextrose buffer, pH 5.5	24 hours	At least 8 mg/mL
Phosphate buffer, pH 6.0	4 hours	At least 5 mg/mL
Phosphate buffer, pH 6.0	24 hours	At least 8 mg/mL
SGF	1 hour	At least 21 mg/mL
FeSSIF	24 hours	At least 4 mg/mL
FaSSIF	1 hour	At least 10 mg/mL
FaSSIF	4 hours	At least 21 mg/mL

The “at least one” structure makes claim 3 relatively broad within the Type A population. A Type A sample need not satisfy every listed test. Meeting one of the specified thresholds may be sufficient, subject to the claim’s testing conditions and construction.

What formulations are protected by US 10,927,142?

Claims 4 through 6 extend protection from the salt itself to pharmaceutical compositions:

Claim 4 covers a composition made by dissolving the claimed citrate salt in a pharmaceutically acceptable carrier.
Claim 5 requires suitability for injection into a human.
Claim 6 narrows the composition to intravenous injection.

These claims target an injectable ibrexafungerp product rather than the currently approved oral Brexafemme tablet.

The formulation claims may be important even if the final injection is a clear solution and no crystals remain at administration. The infringement analysis would focus on the claimed method of making the composition, the identity of the starting salt, and whether the resulting composition satisfies the claim limitations.

Does the patent cover intravenous treatment of invasive candidiasis?

Yes. Claims 7 through 10 cover treatment methods using a pharmaceutical composition containing the claimed citrate salt.

Claim	Scope
7	Treating a fungal infection with an injectable composition
8	Intravenous administration
9	Candida and/or Aspergillus infection
10	Invasive candidiasis and/or invasive aspergillosis

These claims are method-of-treatment claims. They are narrower than a claim covering all uses of ibrexafungerp because they require the claimed citrate salt, a pharmaceutical carrier, an injectable composition, and the specified disease context.

The claimed invasive-infection uses are separate from Brexafemme’s initial FDA-approved indication for vulvovaginal candidiasis. The patent can still have strategic value for future IV development even though the initial label is oral and directed to a different disease.

What is the Orange Book status of US 10,927,142?

Brexafemme is an FDA-approved small-molecule drug and is eligible for Orange Book patent listing. US 10,927,142 is associated with the ibrexafungerp product patent estate and should be evaluated alongside the other patents listed for Brexafemme in the FDA Orange Book.

The patent’s solid-form and formulation claims may be relevant to an abbreviated new drug application if a generic applicant proposes:

The same ibrexafungerp citrate salt.
The same crystalline Type A material.
A process that produces one of the claimed forms.
An injectable formulation using the claimed salt.
A labeling strategy that relies on a patented method of use.

An ANDA applicant must address each listed patent through a Paragraph I, II, III or IV certification. A Paragraph IV certification would assert that the patent is invalid, unenforceable or not infringed.

When does ibrexafungerp lose exclusivity?

Ibrexafungerp’s key exclusivity dates are separate from patent expiration.

Exclusivity or patent event	Date or status
FDA approval of Brexafemme	June 1, 2021
Five-year NCE exclusivity	Expected to end June 1, 2026
US 10,927,142 nominal expiration	February 25, 2035
Potential pediatric extension	Could add six months if awarded
Generic entry absent successful challenge	Generally constrained until relevant patent and regulatory barriers expire

NCE exclusivity prevents submission of an ANDA relying on the innovator’s approval during the five-year period, subject to the statutory Paragraph IV exception during the fourth year. Patent expiry is later and may remain the principal barrier after regulatory exclusivity ends.

Which companies are challenging ibrexafungerp patents?

No publicly established Paragraph IV litigation or settlement involving US 10,927,142 is identified in the patent and FDA materials cited here. The absence of a reported challenge does not establish that no confidential notice, pending ANDA activity or later-filed litigation exists.

The most likely future challengers would be generic manufacturers with antifungal portfolios and sterile or oral solid-dose manufacturing capabilities. A challenger would probably focus on:

Anticipation or obviousness based on prior ibrexafungerp salt and polymorph disclosures.
Lack of enablement across ten crystal forms.
Written-description support for the full form list.
XRPD peak ambiguity and measurement tolerances.
Noninfringement through a noncitrate salt or amorphous product.
Lack of infringement by an oral-only product that does not practice the injectable or IV claims.

How strong is the patent estate for ibrexafungerp?

US 10,927,142 has moderate-to-strong strength against a product using the same citrate solid form, but weaker reach against alternative formulations.

Risk area	Assessment
Same Type A citrate form	High infringement risk
Other claimed citrate forms	High if XRPD criteria are met
Unclaimed crystalline salt	Potential design-around
Amorphous ibrexafungerp citrate	Potential design-around, subject to conversion
Noncitrate salt	Generally outside claim 1
Oral tablet using claimed citrate	Potential exposure under product/composition claims
IV formulation using claimed citrate	High exposure under claims 4-8
Different fungal indication	Method claims may still apply if disease and administration limitations are met
Biosimilar challenge	Not applicable; ibrexafungerp is a small molecule

The patent is strongest where the commercial product is chemically and physically aligned with Type A ibrexafungerp citrate. It is less powerful as a standalone barrier to all ibrexafungerp products.

What generic launch scenarios exist?

Scenario 1: Same citrate form

A generic uses ibrexafungerp citrate with XRPD peaks matching Type A or another claimed form. This presents the clearest infringement risk. A Paragraph IV challenge would likely be required if US 10,927,142 is listed for the reference product.

Scenario 2: Alternative salt

A generic develops a hydrochloride, sulfate, mesylate or other salt. This could avoid claim 1 if the product does not contain citrate. Other compound, composition or regulatory patents could still apply.

Scenario 3: Amorphous material

A generic uses amorphous ibrexafungerp citrate. This may avoid a crystal-form claim, but solid-state conversion during processing or storage could create infringement risk. The generic would also need to establish adequate stability, dissolution and bioequivalence.

Scenario 4: Different crystal form

A nonclaimed citrate polymorph could provide a design-around. The risk would turn on whether the form converts into Type A, Type B, Type E, Type F, Type M, Type N, Type O, Type Q, Type R or Type S under normal conditions.

Scenario 5: Oral-only launch

Claims 5 through 10 focus on injection and IV treatment, but claims 1, 2 and 4 can reach an oral product using the claimed salt or crystal form. An oral generic would therefore not automatically avoid the patent.

What manufacturing and geographic barriers apply?

The patent has territorial effect in the United States. It does not directly block manufacture, sale or use outside the US, although corresponding foreign-family patents may create parallel restrictions.

Manufacturing risks include:

Seeded crystallization of Type A material.
Solvent and water activity conditions that promote polymorph conversion.
Milling or drying that changes XRPD profiles.
Hydration or desolvation during storage.
Batch-to-batch polymorph control.
Use of Type A as an intermediate before dissolution.
Analytical evidence needed to distinguish claimed and unclaimed forms.

A freedom-to-operate program should test the active ingredient at multiple stages: crystallization, drying, milling, formulation, packaging and stability release.

What litigation and settlement issues affect the patent?

A Paragraph IV case would likely address validity and infringement together. The strongest validity arguments would concern:

Prior-art disclosure of ibrexafungerp citrate.
Predictability of citrate salt formation.
Obviousness of selecting the claimed crystal forms.
Whether the XRPD patterns distinguish the forms over the prior art.
Whether the claimed kinetic-solubility results are inherent or unexpected.
Support for the broad list of ten polymorphs.

The strongest patentee arguments would focus on:

Specific XRPD fingerprints.
Multiple experimentally characterized forms.
Solubility and formulation advantages.
Difficulty predicting which crystal form will result.
The commercial and technical need for an injectable salt.

No publicly identified settlement agreement specific to US 10,927,142 is cited here. Any later settlement could establish a licensed generic entry date before the February 2035 patent expiry, but no such date should be assumed without a filed agreement or court record.

How does ibrexafungerp compare with competing antifungals?

Drug	Main class	Administration	Generic or biosimilar risk	Relevance to US 10,927,142
Ibrexafungerp	Glucan synthase inhibitor	Oral approved; IV development claims	Generic risk	Directly covered
Fluconazole	Triazole	Oral and IV	High generic competition	Low direct patent overlap
Echinocandins	Glucan synthase inhibitors	IV	Established generic competition for some products	Clinical substitutes
Rezafungin	Long-acting echinocandin	IV	Patent and development risk	Competing invasive-fungal product
Fosmanogepix	Gwt1 inhibitor prodrug	Oral and IV development	Development-stage patent risk	Competing novel antifungal
Amphotericin B	Polyene	IV and other formulations	Long-established generic competition	Alternative for invasive disease

Ibrexafungerp’s commercial differentiation is its novel mechanism and activity against resistant Candida, while its current FDA-approved product is oral. US 10,927,142 is strategically more important if an IV formulation reaches approval.

Key Takeaways

US 10,927,142 is a solid-form and formulation patent for ibrexafungerp citrate.
Claim 1 covers ten named citrate crystal forms defined by XRPD peaks.
Type A receives additional protection through composition and kinetic-solubility claims.
Claims 4 through 8 create substantial exposure for injectable and intravenous products.
Claims 9 and 10 target invasive Candida and Aspergillus infections.
The patent does not broadly cover every ibrexafungerp product or every ibrexafungerp salt.
A noncitrate salt, amorphous material or nonclaimed polymorph may offer design-around potential.
The nominal expiration date is February 25, 2035, subject to any applicable patent-term adjustment or pediatric extension.
Ibrexafungerp is a small molecule, so biosimilar litigation is not relevant. The principal threat is an ANDA-based generic challenge.
The patent has its greatest blocking power against a generic using the same citrate crystalline material, particularly Type A.

FAQs About US 10,927,142 and Ibrexafungerp Patent Protection

Is US 10,927,142 a patent on Brexafemme tablets?

It can cover tablets that contain the claimed ibrexafungerp citrate crystal form, but its central subject is the citrate salt and its crystalline forms. The patent is not limited to tablets.

Can a generic avoid US 10,927,142 by using amorphous ibrexafungerp?

Potentially. An amorphous product may avoid a crystal-form limitation, but conversion into a claimed crystalline form during manufacture, storage or testing could create infringement issues.

Does US 10,927,142 protect treatment of ordinary vaginal yeast infections?

The provided treatment claims specifically recite fungal infection, Candida and Aspergillus infections, and invasive candidiasis or invasive aspergillosis. They do not expressly recite vulvovaginal candidiasis in the narrower claims.

Does this patent create biosimilar risk?

No. Ibrexafungerp is a chemically synthesized small molecule. The relevant competitive pathway is an ANDA for a generic drug, not a biosimilar application under the Public Health Service Act.

Could an intravenous ibrexafungerp product be blocked even if it uses no crystals at administration?

Yes. Claims 4 through 8 may focus on the salt used to make the composition and the resulting injectable product or treatment method. The disappearance of crystals after dissolution does not automatically eliminate infringement.

References

U.S. Patent and Trademark Office. (2021). U.S. Patent No. 10,927,142 B2: Crystalline forms of ibrexafungerp citrate and pharmaceutical compositions.
U.S. Food and Drug Administration. (2021). Brexafemme prescribing information. SCYNEXIS, Inc.
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book.
U.S. Food and Drug Administration. (2021). FDA approves first oral medication for vaginal yeast infections.
U.S. Patent and Trademark Office. (2024). Patent Center and Patent Term Adjustment databases.

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Glaxosmithkline	BREXAFEMME	ibrexafungerp citrate	TABLET;ORAL	214900-001	Jun 1, 2021		RX	Yes	Yes	⤷ Start Trial	⤷ Start Trial		Y			⤷ Start Trial
>Applicant	>Tradename	>Generic Name	>Dosage	>NDA	>Approval Date	>TE	>Type	>RLD	>RS	>Patent No.	>Patent Expiration	>Product	>Substance	>Delist Req.	>Patented / Exclusive Use	>Submissiondate

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Cyprus	1125272	⤷ Start Trial
Denmark	3247711	⤷ Start Trial
Eurasian Patent Organization	036874	⤷ Start Trial
Eurasian Patent Organization	201791645	⤷ Start Trial
European Patent Office	3247711	⤷ Start Trial
European Patent Office	4039684	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 10,927,142

Which drugs does patent 10,927,142 protect, and when does it expire?

Summary for Patent: 10,927,142