Details for Patent: 12,285,432

Which drugs does patent 12,285,432 protect, and when does it expire?

Patent 12,285,432 protects LEQSELVI and is included in one NDA.

This patent has six patent family members in six countries.

Summary for Patent: 12,285,432

Title:	Treatment of hair loss disorders with deuterated JAK inhibitors
Abstract:	A method of treating a JAK-inhibition-responsive condition (such as a hair loss disorder) in a human subject in need thereof, the method comprising administering to the human subject a therapeutically effective amount of Compound (I) or a pharmaceutically acceptable salt thereof, wherein each position designated specifically as deuterium has at least 95% incorporation of deuterium; and wherein: the subject is receiving a concomitant administration of a CYP3A4 inhibitor; and the therapeutically effective amount of Compound (I), or a pharmaceutically acceptable salt thereof, is not reduced compared to the therapeutically effective amount of Compound (I), or pharmaceutically acceptable salt thereof, that would be administered to the subject in the absence of concomitant administration of a CYP3A4 inhibitor.
Inventor(s):	James V. Cassella, Christopher L. Brummel
Assignee:	Sun Pharmaceutical Industries Inc
Application Number:	US18/382,307
Patent Claim Types: see list of patent claims	Use; Formulation; Dosage form;

US Patent 12,285,432: Scope, Claims, Exclusivity and Patent Landscape for Deuterated Ruxolitinib in Alopecia Areata

US Patent 12,285,432 protects a treatment protocol for alopecia areata and related severe forms of hair loss using a highly deuterated form of ruxolitinib, generally associated with deuruxolitinib, in patients receiving a CYP3A4 inhibitor. The patent does not broadly claim every use of the compound. Its central limitation is the decision to maintain the standard Compound (I) dose despite concomitant CYP3A4-inhibitor therapy.

The claims cover:

• Oral Compound (I) doses of about 4 mg to about 50 mg.
• Alopecia areata, alopecia totalis and alopecia universalis.
• At least 95% deuterium incorporation at each specified deuterium position.
• Concomitant administration of about 0.1 mg to about 200 mg of a CYP3A4 inhibitor.
• No reduction or adjustment of the Compound (I) dose because of the CYP3A4 inhibitor.
• Optional strong CYP3A4 inhibitors.
• 16 mg/day and 24 mg/day regimens administered twice daily.
• Tablet formulations.
• Treatment outcomes in which the SALT score is 20 or less.
• A clinical decision step determining whether the patient is receiving a CYP3A4 inhibitor.

What drug does US Patent 12,285,432 cover?

The claims identify the active agent only as Compound (I) and refer to a structural formula that is not reproduced in the supplied claim text. The claimed compound appears to be the deuterated ruxolitinib program associated with deuruxolitinib, also known as CTP-543.

Deuruxolitinib is a deuterated form of ruxolitinib, a Janus kinase inhibitor. Deuterium substitution is intended to modify metabolic behavior while retaining the pharmacologic activity of the parent molecule. The relevant commercial product is Leqselvi, approved by the FDA for severe alopecia areata in adults and marketed by Sun Pharmaceutical Industries following its agreement with Concert Pharmaceuticals.

The chemical identity must be confirmed against the issued patent’s drawings and specification because the structural formula is absent from the claim text supplied here. The legal analysis below therefore treats Compound (I) as the deuterated ruxolitinib compound represented in the patent.

What are the independent claims in US Patent 12,285,432?

The patent has four independent method claims: claims 1, 8, 15 and 22.

Claim	Core legal theory	Distinguishing requirement
1	Treat hair loss with Compound (I) while co-administering a CYP3A4 inhibitor	No dose adjustment is required because of the inhibitor
8	Treat hair loss with Compound (I) during concomitant CYP3A4-inhibitor use	Compound (I) dose is not reduced compared with inhibitor-free treatment
15	Treat hair loss after determining that the patient is receiving a CYP3A4 inhibitor	Standard Compound (I) dose is maintained
22	Determine whether the patient is taking a CYP3A4 inhibitor, then administer Compound (I) if so	Decision step plus no dose reduction

Claims 1, 8 and 15 are closely overlapping. Their differences are primarily drafting variations:

• Claim 1 states that no dosage adjustment is required.
• Claim 8 states that the dose is not reduced.
• Claim 15 requires that the subject has been determined to be receiving the inhibitor.
• Claim 22 expressly requires a screening or determination step before administration.

The claims are method-of-treatment claims, not composition claims. They do not independently claim the deuterated molecule, a tablet containing it, or a manufacturing process.

What diseases and patient populations are protected?

The independent claims cover three related hair-loss disorders:

1. Alopecia areata.
2. Alopecia totalis.
3. Alopecia universalis.

Dependent claims 2, 9, 16 and 23 narrow the indication to alopecia areata. This is commercially important because the FDA-approved indication for deuruxolitinib is severe alopecia areata, while alopecia totalis and alopecia universalis represent more extensive clinical phenotypes.

The claims are limited to a human subject in need of treatment. They do not expressly require:

• A specific baseline SALT score.
• Adult age.
• A minimum duration of disease.
• Prior failure of another therapy.
• A particular sex or ethnicity.
• A specific formulation beyond the tablet limitation in dependent claims.

Claim 5, 12, 19 and 26 add a post-treatment endpoint requiring a SALT score of 20 or less. These claims are narrower than the independent claims because infringement would require proof of the claimed treatment and the specified clinical result.

What doses and formulations are protected?

The broad dose range is about 4 mg to about 50 mg administered orally. The most commercially relevant dependent claims identify:

• 16 mg/day, administered as 8 mg twice daily.
• 24 mg/day, administered as 12 mg twice daily.
• Tablet formulations.

The claims use the word “about,” which creates a potential range-construction issue. Courts generally assess “about” in view of the specification, examples, analytical precision and technical context. The patent’s clinical dosing examples and disclosure will be important in determining whether a competing dose falls inside or outside the claimed range.

The tablet limitation appears only in dependent claims 4, 11, 18 and 25. A competing oral capsule, liquid, granule or other dosage form could avoid those dependent claims, but it could still fall within the broader independent claims if all other limitations are met.

How does the CYP3A4 inhibitor limitation affect claim scope?

The CYP3A4 limitation is the principal narrowing feature. A potential infringing regimen must involve:

• A human patient receiving a CYP3A4 inhibitor.
• An inhibitor amount of about 0.1 mg to about 200 mg.
• Oral administration of Compound (I).
• A Compound (I) dose that is not reduced because of the inhibitor.

The claims also include a dependent limitation for a strong CYP3A4 inhibitor. The patent does not identify a single inhibitor in the claims supplied. The specification may identify examples such as itraconazole, ketoconazole, clarithromycin, ritonavir, cobicistat or other strong inhibitors, but infringement analysis must use the issued patent’s actual disclosure and the applicable FDA or regulatory classification.

The requirement that no adjustment be made is both a scope limitation and a likely prosecution-history issue. If the applicant distinguished prior art by emphasizing the maintained dose, that argument could limit the patentee’s ability to interpret the claims broadly. A regimen that reduces Compound (I), interrupts the inhibitor, or avoids the inhibitor would generally fall outside the independent claims as written.

What does the deuterium limitation require?

Each position designated as deuterium must have at least 95% deuterium incorporation. This is a material structural limitation.

A product containing a mixture of deuterated and nondeuterated molecules could raise infringement questions if any specified position has less than 95% incorporation. The relevant measurement would likely depend on the patent’s analytical method, batch testing procedures and the identity of the deuterated positions.

The limitation creates a potential manufacturing and quality-control barrier. A generic or follow-on manufacturer would need to control:

• Isotopic purity.
• Site-specific deuterium incorporation.
• Batch-to-batch consistency.
• Salt form and solid-state properties.
• Analytical methods used to establish the 95% threshold.

A nondeuterated ruxolitinib product would not satisfy the deuterium limitation, even if used for the same disease. A deuterated product with a different substitution pattern may also avoid the claims if it is not Compound (I).

What is the patent strength of US Patent 12,285,432?

The patent has moderate-to-strong blocking potential for the specific drug-interaction scenario, but limited breadth outside that scenario.

Strengths

• The claims cover the commercially relevant 8 mg twice-daily and 12 mg twice-daily regimens.
• The claims expressly include strong CYP3A4 inhibitors.
• The claims capture both the treatment act and the clinical dosing decision.
• The claims use multiple independent formulations of the same core concept.
• The 95% deuterium requirement can create a meaningful technical barrier for manufacturers.

Limitations

• The claims do not broadly cover all uses of Compound (I).
• CYP3A4-inhibitor co-administration is required.
• The dose must not be reduced because of the inhibitor.
• The claim set does not independently cover the compound, composition or manufacturing process.
• The SALT endpoint claims require proof of a clinical outcome and may be difficult to enforce against individual treatment decisions.
• The duplicated “(ii)” numbering in claims 8 and 15 is a drafting defect, although it would not ordinarily invalidate the claims if the intended limitations are clear from the prosecution record.

The strongest commercial claims are likely claims 1, 8 and 15, particularly where a label, prescribing protocol or clinical trial expressly directs use of the standard dose with a CYP3A4 inhibitor.

When does US Patent 12,285,432 expire?

A precise expiration date cannot be reliably calculated from the claims alone. The relevant date depends on:

• The earliest effective nonprovisional priority date.
• Any patent-term adjustment.
• Any terminal disclaimer.
• Patent-term extension.
• A patent-term adjustment statement on the issued patent.
• Whether the patent is a continuation with a parent application that affects the term calculation.

US utility patents generally expire 20 years from the earliest effective nonprovisional filing date, subject to statutory adjustments under 35 U.S.C. §§ 154 and 156. The issue date of US Patent 12,285,432 is not itself the expiration date.

The patent should be analyzed with the USPTO Patent Center continuity data and the issued patent’s patent-term information. A continuation patent may have a later issue date but an expiration date tied to an earlier parent filing.

What is the Orange Book status of US Patent 12,285,432?

The FDA Orange Book listing must be assessed separately from patent issuance. A patent may be relevant to an approved drug without being listed, and listing eligibility depends on the patent’s relationship to the approved product and labeling.

For a method-of-use patent, Orange Book listing generally requires that the patent claim an approved method of using the drug. The relevant question is whether the approved Leqselvi labeling covers use of the product with the claimed CYP3A4-inhibitor protocol.

The patent’s commercial value may therefore depend on whether:

• It is listed against the approved product.
• The FDA-approved labeling contains the claimed use.
• The listed patent is categorized as a method-of-use patent.
• The Orange Book entry includes a use code that accurately describes the claimed method.
• A generic applicant can carve out the patented use through a section viii statement.

If the approved label instructs dose reduction or avoidance of strong CYP3A4 inhibitors, that labeling could weaken the practical fit between the patent claims and the approved indication. If the label permits the standard dose during inhibitor use, the Orange Book position would be more consequential.

What Paragraph IV challenges and generic-entry risks exist?

A generic applicant could challenge the patent through an ANDA Paragraph IV certification if the patent is listed for the reference product. The principal potential grounds would include:

• Lack of written description for the claimed inhibitor combinations or dose range.
• Lack of enablement across the broad 0.1 mg to 200 mg inhibitor range.
• Obviousness based on known CYP3A4 interactions, deuterated ruxolitinib disclosures and clinical dosing information.
• Indefiniteness of “about,” “strong CYP3A4 inhibitor” or “no adjustment.”
• Lack of infringement based on a label that excludes or reduces dosing with CYP3A4 inhibitors.
• Noninfringement based on a different deuterium incorporation profile.
• Invalidity based on prior clinical or patent disclosures involving the same co-administration protocol.

The most credible design-around would be a label that instructs dose reduction, prohibits use with strong inhibitors, or omits the patented concomitant-use method. Such a carve-out would not eliminate all litigation risk because induced-infringement theories can arise from prescribing practices, promotional activity and labeling language.

Which companies are relevant to the competitive landscape?

Company	Product	Mechanism or status	Relevance
Sun Pharmaceutical Industries	Leqselvi, deuruxolitinib	Deuterated JAK inhibitor	Commercial product associated with Compound (I)
Concert Pharmaceuticals	CTP-543 program	Originator of deuruxolitinib program	Patent and licensing origin
Pfizer	Litfulo, ritlecitinib	Oral JAK3/TEC-family inhibitor	Approved competing treatment for severe alopecia areata
Eli Lilly	Olumiant, baricitinib	Oral JAK1/JAK2 inhibitor	Approved alopecia areata competitor
Generic manufacturers	Future ruxolitinib or deuruxolitinib products	ANDA pathway	Potential Paragraph IV challengers

Biosimilar risk is low because Compound (I) is a small-molecule drug rather than a biologic. The relevant entry pathway is an ANDA or, for a distinct molecular product, a 505(b)(2) application. The main competitive risks are therefore generic substitution, label carve-outs and competing oral JAK inhibitors.

What licensing deals affect the patent estate?

Concert Pharmaceuticals developed CTP-543 and entered into a commercialization arrangement with Sun Pharmaceutical Industries. Sun acquired Concert in 2023, bringing the CTP-543 program and related intellectual property into the Sun organization.

The transaction reduces uncertainty over commercial control of the patent estate. It also aligns the product sponsor, regulatory holder and patent owner within the same corporate group. The precise ownership of US Patent 12,285,432 should be verified in the USPTO assignment records because patent title, exclusive license rights and Orange Book listing rights can differ.

What patent litigation affects deuruxolitinib?

The supplied claim set does not identify a litigation action, Paragraph IV notice or settlement. A complete litigation determination requires review of federal court dockets, FDA Orange Book certifications and any ANDA notice letters.

The principal litigation exposure would involve:

• Patent listing and use-code disputes.
• Paragraph IV invalidity and noninfringement claims.
• Label-scarve-out disputes.
• Induced infringement based on CYP3A4 co-prescribing.
• Ownership or assignment challenges.
• Competing patents covering the deuterated compound, salts, formulations, treatment regimens or manufacturing processes.

No biosimilar litigation framework applies to this small-molecule product.

How does this patent compare with competing alopecia areata patents?

US Patent 12,285,432 is narrower than a compound patent but potentially more specific than a conventional method-of-use patent. It targets a pharmacokinetic management problem: maintaining the Compound (I) dose when a CYP3A4 inhibitor is administered.

A compound patent would generally provide broader exclusionary power. A formulation patent could block particular tablets or release profiles. A conventional alopecia areata method patent could cover treatment without requiring CYP3A4 co-administration. This patent’s value is highest when the approved product label or standard clinical practice includes the claimed interaction scenario.

Key Takeaways

• US Patent 12,285,432 is directed to deuterated Compound (I), associated with deuruxolitinib, for alopecia areata and related disorders.
• The core invention is maintaining the Compound (I) dose during CYP3A4-inhibitor treatment.
• The principal dose embodiments are 8 mg twice daily and 12 mg twice daily.
• The claims require at least 95% deuterium incorporation at specified positions.
• Tablet, strong-inhibitor and SALT-score limitations appear only in dependent claims.
• The patent does not broadly cover every use, formulation or manufacture of deuruxolitinib.
• Generic risk depends heavily on Orange Book listing, approved labeling and the ability to use a section viii carve-out.
• Biosimilar risk is not material because the product is a small molecule.
• Exact patent expiration and Orange Book status require the issued patent’s continuity, assignment and FDA listing records.

FAQs

Does US Patent 12,285,432 cover ordinary ruxolitinib?

No. The claims require Compound (I) with specified deuterium incorporation of at least 95% at each designated position. Ordinary nondeuterated ruxolitinib would not meet that limitation.

Does a patient have to take a strong CYP3A4 inhibitor for infringement?

Not under the independent claims. The independent claims cover a CYP3A4 inhibitor generally. Strong CYP3A4 inhibition is a dependent-claim limitation.

Would reducing the Compound (I) dose avoid the patent?

Potentially. The independent claims require that no dose adjustment be made or that the amount not be reduced because of the CYP3A4 inhibitor. A regimen using a reduced Compound (I) dose could avoid those limitations, subject to the full patent text and prosecution history.

Are the 16 mg/day and 24 mg/day regimens the only protected doses?

No. The independent claims cover about 4 mg to about 50 mg. The 16 mg/day and 24 mg/day regimens are narrower dependent-claim embodiments.

Can a competitor avoid the patent by using a capsule instead of a tablet?

A capsule may avoid the tablet-dependent claims, but it would not necessarily avoid the independent claims. The independent claims require oral administration but do not require a tablet.

References

1. U.S. Patent and Trademark Office. (2025). U.S. Patent No. 12,285,432. Washington, DC: U.S. Department of Commerce.

2. U.S. Food and Drug Administration. (2024). FDA approves first treatment for severe alopecia areata. Silver Spring, MD: U.S. Department of Health and Human Services.

3. U.S. Food and Drug Administration. (2024). Leqselvi (deuruxolitinib) prescribing information. Silver Spring, MD: U.S. Department of Health and Human Services.

4. U.S. Food and Drug Administration. (2025). Approved drug products with therapeutic equivalence evaluations: Orange Book. Silver Spring, MD: U.S. Department of Health and Human Services.

5. U.S. Patent and Trademark Office. (2025). Patent Center: Patent examination and continuity records for U.S. Patent No. 12,285,432. Washington, DC: U.S. Department of Commerce.

6. Concert Pharmaceuticals, Inc. (2023). Sun Pharmaceutical Industries completes acquisition of Concert Pharmaceuticals. Lexington, MA.

Drugs Protected by US Patent 12,285,432

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Sun Pharm Inds Inc	LEQSELVI	deuruxolitinib phosphate	TABLET;ORAL	217900-001	Jul 25, 2024		RX	Yes	Yes	12,285,432					TREATMENT OF ADULT PATIENTS WITH ALOPECIA AREATA

International Family Members for US Patent 12,285,432

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2022328272
Canada	3228505
China	118159272
European Patent Office	4384175
Japan	2024531188