Details for Patent: 9,617,258

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Which drugs does patent 9,617,258 protect, and when does it expire?

Patent 9,617,258 protects LITFULO and is included in one NDA.

This patent has sixty-four patent family members in forty-four countries.

Summary for Patent: 9,617,258

Title:	Pyrrolo[2,3-d]pyrimidinyl, pyrrolo[2,3-b]pyrazinyl and pyrrolo[2,3-d]pyridinyl acrylamides
Abstract:	The present invention provides pharmaceutically active pyrrolo[2,3-d]pyrimidinyl and pyrrolo[2,3-d]pyridinyl acrylamides and analogues thereof, having the structure: or a pharmaceutically acceptable salt or solvate thereof, or an enantiomer or diastereomer thereof, as set forth in the Description. Such compounds are useful for inhibiting Janus Kinase (JAK). This invention also is directed to compositions comprising methods for making such compounds, and methods for treating and preventing conditions mediated by JAK.
Inventor(s):	Atli Thorarensen, Matthew Frank Brown, Agustin Casimiro-Garcia, Ye CHE, Jotham Wadsworth Coe, Mark Edward Flanagan, Adam Matthew Gilbert, Matthew Merrill Hayward, Jonathan David Langille, Justin Ian Montgomery, Jean-Baptiste Telliez, Rayomand Jal Unwalla, John I. Trujillo
Assignee:	Pfizer Inc
Application Number:	US14/559,294
Patent Claim Types: see list of patent claims	Composition; Compound;

US Patent 9,617,258: Ritlecitinib Patent Scope, Claims, Expiration and Competitive Landscape

US Patent No. 9,617,258 covers a broad class of acrylamide-substituted aminopyrrolopyrimidine compounds, including ritlecitinib, the active ingredient in Pfizer’s Litfulo product. The patent claims the chemical compound, stereochemical forms, salts and solvates, selected specific analogs, and pharmaceutical or veterinary compositions. Its commercial significance is highest for covalent Janus kinase 3 (JAK3) and TEC-family kinase inhibition.

The principal compound claims are composition-of-matter claims. They are materially stronger than formulation or method-of-use claims because a commercial product can infringe based on its chemical identity alone.

What drug does US Patent 9,617,258 protect?

US 9,617,258 protects ritlecitinib-related pyrrolopyrimidine compounds. Ritlecitinib is marketed in the United States as Litfulo for severe alopecia areata in adults and adolescents at least 12 years old.

The claimed chemical series contains four defining structural elements:

1. A pyrrolo[2,3-d]pyrimidine or related pyrrolopyridine heteroaromatic core.
2. An amino linkage connecting the heteroaromatic core to a substituted piperidine.
3. An N-acryloyl group on the piperidine nitrogen.
4. Broad substitution and stereochemical coverage around the heteroaromatic ring and piperidine ring.

The acrylamide is the principal electrophilic warhead. It enables irreversible covalent binding to a cysteine residue in targeted kinases, including JAK3 and TEC-family kinases. The heteroaromatic-piperidine portion provides kinase-binding interactions and controls potency, selectivity, and pharmacokinetic properties.

Pfizer’s ritlecitinib development code was PF-06651600. FDA approved Litfulo on June 23, 2023, for severe alopecia areata. The approval was based on the new drug application pathway for a small-molecule drug, not the biologics license application pathway.[1]

What are the main claim categories in US 9,617,258?

Claim	Subject matter	Commercial significance
1	Broad Markush genus of compounds, salts, solvates, enantiomers and diastereomers	Broad chemical composition coverage
2	Narrower structural subgenus with hydrogen at specified positions	Intermediate scope
3	Enumerated individual compounds	Specific species coverage
4	A defined methyl-substituted piperidine compound	Narrow species claim
5	A defined 2-methylpiperidine compound	Narrow species claim, likely relevant to ritlecitinib chemistry
6	Pharmaceutical or veterinary composition containing a claim 1 compound	Composition coverage

Claims 1 through 3 carry most of the patent’s chemical breadth. Claims 4 and 5 provide fallback positions for selected stereochemical compounds. Claim 6 extends protection to drug products containing a covered compound and a pharmaceutically acceptable carrier.

How broad is claim 1 of US 9,617,258?

Claim 1 is a large Markush claim. It does not claim only one molecule. It covers a family of compounds defined by variable substituents at multiple positions.

Heteroaromatic substituent coverage

R2 may include hydrogen, deuterium, alkyl, cycloalkyl, aryl, heteroaryl, heterocyclic groups, alkoxy, perfluoroalkoxy, halogen, cyano, hydroxyl, amino, carboxy, sulfonyl and sulfonamide-related substituents.

This language can cover:

• Unsubstituted pyrrolopyrimidines.
• Halogenated analogs.
• Alkyl-substituted analogs.
• Fluoro and cyano analogs.
• Heteroaryl and heterocyclic analogs.
• Sulfonyl-substituted analogs.
• Deuterated versions.
• Substituted aryl and heteroaryl derivatives.

The claim also permits optional substitution on several of those groups. That substantially enlarges the theoretical genus.

Piperidine substitution

R3, Ra, Rb, Rc and Rd cover hydrogen, alkyl, perfluoroalkyl, arylalkyl, heteroarylalkyl, heterocyclic alkyl, halogen, cyano, hydroxy, alkoxy, amino and carboxy-related groups.

The claim separately allows ring atoms or substituents to form bonds or C1-C6 alkyl chains. This language is directed to fused, bridged or otherwise constrained piperidine derivatives.

Stereochemical coverage

The claim expressly covers enantiomers and diastereomers. Claim 3 lists multiple stereochemically defined compounds, including:

• 3-substituted piperidines.
• 2-methyl and 2-ethyl piperidines.
• 4-methyl and 4-fluoro piperidines.
• 5-hydroxy and 5-fluoro piperidines.
• 5-methyl, 5-chloro and 5-cyano heteroaromatic analogs.

This is important because a generic developer cannot necessarily avoid the patent by selecting a different stereoisomer of the same core structure.

Does US 9,617,258 specifically claim ritlecitinib?

The supplied claim text identifies the compound in claim 5 as:

1-((2S,5R)-5-(7H-pyrrolo[2,3-d]pyrimidin-4-ylamino)-2-methylpiperidin-1-yl)prop-2-en-1-one

That compound corresponds to ritlecitinib’s core chemical structure. The claim therefore provides direct composition-of-matter coverage for the active ingredient rather than relying only on a broad genus claim.

The claim text also contains a separate claim to a 3R,4S methyl-substituted piperidine analog. That compound is structurally related but should not automatically be treated as identical to ritlecitinib. Patent infringement analysis requires exact atom connectivity, stereochemistry and substitution mapping.

What is the claim scope for formulations?

Claim 6 covers a pharmaceutical or veterinary composition containing a claim 1 compound and a pharmaceutically acceptable carrier.

The claim is broad because it does not require:

• A particular tablet or capsule formulation.
• A defined dose.
• A specific excipient.
• A controlled-release system.
• A particular particle size.
• A specified polymorph.
• A specific route of administration.

A solid oral dosage form containing ritlecitinib would generally fall within the literal scope of claim 6 if the active ingredient satisfies claim 1 or one of its dependent claims.

The claim does not appear, based on the supplied text, to provide detailed protection for:

• A particular polymorphic form.
• A specific crystalline form.
• A defined salt selected by solid-state properties.
• A particular dissolution profile.
• A fixed-dose combination.
• A specific tablet-coating system.
• A manufacturing process.

Those subjects may be covered by separate patents or patent applications in the Litfulo family.

What are the patent expiration and exclusivity dates?

The patent has a 2013 priority date and a nominal 20-year term measured from the earliest effective nonprovisional filing date, subject to patent-term adjustment and any applicable patent-term extension.

Event	Date or period
Earliest reported priority period	March 2013
US patent grant	April 11, 2017
FDA approval of Litfulo	June 23, 2023
Expected ordinary patent-term endpoint	Approximately March 2034
FDA new chemical entity exclusivity	Through approximately June 2028
Earliest ordinary generic filing risk	Before June 2028 through Paragraph IV certification
Earliest possible commercial generic entry	Controlled by litigation, settlement and applicable exclusivity

The exact expiration date should be taken from the current USPTO patent record because patent-term adjustment can move the statutory endpoint beyond the basic 20-year calculation. A patent expiration date is not the same as FDA marketing exclusivity. The NCE exclusivity period and patent term operate independently.

What is the Orange Book status of US 9,617,258?

Litfulo’s Orange Book listing should be evaluated separately from the patent’s intrinsic claim scope. An Orange Book listing normally identifies patents that the NDA holder represents as covering the approved drug, its formulation or an approved method of use.

For a listed drug patent, a generic applicant submitting an ANDA may need to make one of the statutory certifications under 21 U.S.C. § 355(j)(2)(A)(vii):

• Paragraph I: no patent information has been submitted.
• Paragraph II: the patent has expired.
• Paragraph III: the applicant will wait until patent expiration.
• Paragraph IV: the patent is invalid, unenforceable or will not be infringed.

A Paragraph IV certification is a statutory act of infringement under 35 U.S.C. § 271(e)(2)(A) and can trigger patent litigation if the NDA holder sues within the statutory period.

The supplied claim set alone does not establish the complete current Orange Book listing, any delisting, or the existence of a current Paragraph IV notice. Those facts depend on FDA Orange Book data and litigation records.

Are there method-of-use patents for Litfulo?

US 9,617,258 is principally a compound and composition patent based on the supplied claims. It does not contain a conventional method-of-use claim in the text provided.

Litfulo may be protected by separate patents covering:

• Treatment of alopecia areata.
• Treatment of autoimmune or inflammatory disorders.
• Dosing regimens.
• Patient populations.
• Oral administration.
• Combination treatment.
• Safety-related dosing restrictions.

A generic applicant can sometimes avoid a method-of-use patent through a section viii statement that omits the patented indication from its labeling. That strategy is more difficult when the product’s approved labeling contains only, or primarily, the patented use.

What patent families are likely relevant to ritlecitinib?

The relevant estate should be divided into five categories.

Core composition patents

These cover the pyrrolopyrimidine acrylamide compounds and are the most important patents for a generic competitor. US 9,617,258 belongs in this category.

Continuations and divisional applications

Continuation practice can produce narrower patents directed to:

• A specific active compound.
• A selected stereoisomer.
• A salt.
• A pharmaceutical composition.
• A narrower substituent class.
• A particular therapeutic use.

A continuation may remain pending or issue after the parent patent. The existence of US 9,617,258 does not establish that it is the only enforceable US patent in the family.

Formulation patents

Separate patents may cover tablet composition, stability, granulation, particle engineering, coating, or dosage form. These patents are usually narrower than composition-of-matter claims but can delay an unlicensed commercial launch.

Method-of-use patents

These may cover alopecia areata or other JAK3/TEC-mediated diseases. Their practical value depends on the approved labeling and whether a generic applicant can carve out the patented use.

Manufacturing patents

The active ingredient contains multiple stereochemical and functional-group control points. Manufacturing patents may address:

• Construction of the substituted piperidine.
• Enantioselective synthesis.
• Coupling of the heteroaromatic core.
• Installation of the acrylamide.
• Crystallization or salt formation.
• Impurity control.

A manufacturing patent does not necessarily prevent a generic company from using a noninfringing process. The composition patent is usually the more significant barrier.

How strong is the patent estate?

The core estate is strong against a direct generic copy because claim 5 appears to identify the ritlecitinib molecule itself. A generic product containing the same active ingredient cannot avoid composition-of-matter infringement merely by changing excipients, tablet shape or manufacturing location.

The estate is weaker against a program that:

• Uses a different kinase inhibitor scaffold.
• Removes or changes the acrylamide warhead.
• Selects a noncovered heteroaromatic core.
• Uses a materially different piperidine replacement.
• Develops a different JAK3 or TEC-family inhibitor.

Strength assessment

Issue	Assessment
Direct generic copy of ritlecitinib	High infringement risk
Different salt of ritlecitinib	Usually remains high risk if claim covers the parent compound and pharmaceutically acceptable salts
Different polymorph	Does not necessarily avoid compound claims
Different excipient formulation	Usually does not avoid composition claims
Deuterated analog	Potentially covered by claim 1, subject to exact structure
Different stereoisomer	Potentially covered because enantiomers and diastereomers are expressly included
Alternative synthesis route	Does not avoid product claims
Different kinase inhibitor scaffold	Lower risk, subject to separate patents
Generic alopecia areata label carve-out	May reduce method-of-use exposure but does not avoid compound claims

Which companies are challenging the patent?

The supplied record does not establish a current Paragraph IV challenger, ANDA filing, patent litigation docket or settlement agreement involving US 9,617,258. A definitive challenger analysis requires current FDA, PACER and district-court records.

No challenger should be inferred merely from the patent’s age or from the existence of Litfulo’s Orange Book listing. A Paragraph IV notice is private initially and may not be publicly confirmed until litigation is filed or the applicant’s notice becomes visible through other records.

What generic launch scenarios exist?

Scenario 1: No successful challenge

The generic launch remains blocked until the relevant composition patents expire or are otherwise invalidated, licensed or settled.

Scenario 2: Paragraph IV litigation and early settlement

The generic applicant may agree to a negotiated entry date before patent expiration. The commercial effect depends on the settlement date, authorized-generic terms and whether the settlement covers all relevant patents.

Scenario 3: Invalidity or noninfringement victory

A successful challenge to the core composition patent could permit launch before nominal expiration, subject to other listed patents and FDA exclusivity.

Scenario 4: Authorized generic

Pfizer could introduce or license an authorized generic. That would reduce the economic value of an independent ANDA launch even if legal entry becomes available.

Scenario 5: Paragraph III or delayed filing

A generic applicant may accept patent validity and defer launch until the relevant patent term ends. This avoids litigation but gives up early-entry economics.

How does ritlecitinib’s patent position compare with competing alopecia areata drugs?

Product	Active ingredient	Main sponsor	Patent-risk profile
Litfulo	Ritlecitinib	Pfizer	Core small-molecule composition patent, use and possible formulation coverage
Olumiant	Baricitinib	Eli Lilly/Incyte	Older JAK inhibitor estate; separate composition and use patents
Cibinqo	Abrocitinib	Pfizer	Separate JAK1 composition and use estate
Velsipity and other immunomodulators	Different mechanisms	Multiple companies	Not direct chemical substitutes, but compete clinically and commercially

Ritlecitinib differs from broad JAK1/JAK2 inhibitors because it was designed for selective JAK3 and TEC-family inhibition. That pharmacology does not itself determine patent infringement, but it narrows the most commercially relevant design-around field.

What is the revenue exposure?

Litfulo revenue exposure is concentrated in the period before the core composition claims expire. The product’s commercial value depends on:

• Persistence of the alopecia areata indication.
• Uptake among adolescents and adults.
• Reimbursement coverage.
• Competition from baricitinib and emerging oral or biologic therapies.
• The number and scope of Orange Book-listed patents.
• The timing of any Paragraph IV challenge.
• The existence of continuation patents extending practical protection.

A direct generic launch would likely produce a sharp price decline because the active ingredient is a small molecule administered orally. Patent expiry is therefore more commercially significant than it would be for a complex biologic requiring biosimilar interchangeability and manufacturing comparability.

Does biosimilar risk apply to Litfulo?

No. Litfulo is a chemically synthesized small-molecule drug, not a biologic. The relevant competitive pathway is an ANDA for a generic drug under section 505(j) of the Federal Food, Drug, and Cosmetic Act, not a biosimilar application under section 351(k) of the Public Health Service Act.

The principal regulatory risks are:

• Paragraph IV patent litigation.
• Therapeutic-equivalence requirements.
• Pharmaceutical-equivalence requirements.
• Labeling carve-outs.
• FDA exclusivity timing.
• Additional Orange Book patents.

Key Takeaways

• US 9,617,258 is a core composition patent for ritlecitinib-related acrylamide pyrrolopyrimidines.
• Claim 1 is a broad Markush genus covering extensive heteroaromatic, piperidine, stereochemical and salt variation.
• Claim 5 directly identifies the ritlecitinib chemical structure described in the supplied claims.
• Claim 6 covers pharmaceutical and veterinary compositions containing a covered compound.
• The patent is materially stronger against a direct generic copy than against a new JAK3 or TEC inhibitor using a different scaffold.
• The expected basic patent-term endpoint is approximately March 2034, subject to patent-term adjustment and the authoritative USPTO record.
• FDA NCE exclusivity for Litfulo runs for approximately five years from the June 23, 2023 approval date.
• Litfulo faces generic, not biosimilar, competition.
• The supplied claims do not establish the complete current Orange Book listing, Paragraph IV activity, litigation record or settlement history.

FAQs

Does changing ritlecitinib to a different salt avoid US 9,617,258?

Usually not if the selected salt is a pharmaceutically acceptable salt of the claimed compound. Claim 1 expressly includes pharmaceutically acceptable salts and solvates.

Can a generic company avoid the patent by using a different manufacturing process?

No, not if the final product is the claimed compound. A different synthesis route does not avoid a product claim, although it may avoid a separate process patent.

Does a polymorph automatically receive separate patent protection?

No. A polymorph may be covered by a separate solid-state patent, but it can also remain within a broader compound claim if the claim covers the underlying active ingredient and salt form.

Is a different ritlecitinib stereoisomer outside the patent?

Not necessarily. The supplied claim language expressly covers enantiomers and diastereomers. Exact stereochemical mapping is required.

Can a generic launch before 2034 if it removes alopecia areata from the label?

A label carve-out may address a method-of-use patent, but it does not avoid a composition-of-matter patent covering ritlecitinib itself. A generic applicant would still need to resolve the core compound patent and any other listed patents.

References

1. U.S. Food and Drug Administration. (2023, June 23). FDA approves first systemic treatment for alopecia areata.
2. U.S. Patent No. 9,617,258. (2017). Pyrrolopyrimidine compounds and pharmaceutical compositions. United States Patent and Trademark Office.
3. U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book.
4. United States Code, 21 U.S.C. § 355.
5. United States Code, 35 U.S.C. § 271.

Drugs Protected by US Patent 9,617,258

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Pfizer	LITFULO	ritlecitinib tosylate	CAPSULE;ORAL	215830-001	Jun 23, 2023		RX	Yes	Yes	9,617,258		Y	Y

International Family Members for US Patent 9,617,258

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
European Patent Office	3077395		301245	Netherlands
European Patent Office	3077395		CA 2023 00028	Denmark
European Patent Office	3077395		LUC00322	Luxembourg
European Patent Office	3077395		PA2023537	Lithuania
European Patent Office	3077395		2023C/544	Belgium