Details for Patent: 7,838,531

Which drugs does patent 7,838,531 protect, and when does it expire?

Patent 7,838,531 protects ZOKINVY and is included in one NDA.

This patent has nine patent family members in six countries.

Summary for Patent: 7,838,531

Title:	Farnesyltransferase inhibitors for treatment of laminopathies, cellular aging and atherosclerosis
Abstract:	Although it can be farnesylated, the mutant lamin A protein expressed in Hutchison Gilford Progeria Syndrome (HGPS) cannot be defarnesylated because the characteristic mutation causes deletion of a cleavage site necessary for binding the protease ZMPSTE24 and effecting defarnesylation. The result is an aberrant farnesylated protein (called “progerin”) that alters normal lamin A function as a dominant negative, as well as assuming its own aberrant function through its association with the nuclear membrane. The retention of farnesylation, and potentially other abnormal properties of progerin and other abnormal lamin gene protein products, produces disease. Farnesyltransferase inhibitors (FTIs) (both direct effectors and indirect inhibitors) will inhibit the formation of progerin, cause a decrease in lamin A protein, and/or an increase prelamin A protein. Decreasing the amount of aberrant protein improves cellular effects caused by and progerin expression. Similarly, treatment with FTIs should improve disease status in progeria and other laminopathies. In addition, elements of atherosclerosis and aging in non-laminopathy individuals will improve after treatment with farnesyltransferase inhibitors.
Inventor(s):	Leslie B. Gordon, Francis S. Collins, Thomas Glover, Michael W. Glynn, Brian C. Capell, Adrienne D. Cox, Channing J. Der
Assignee:	University of North Carolina at Chapel Hill , University of Michigan System , Progeria Research Foundation Inc , US Department of Health and Human Services
Application Number:	US11/828,117
Patent Claim Types: see list of patent claims	Use;

United States Patent 7,838,531: Scope, Claims, Expiration, and FTI Patent Landscape

U.S. Patent No. 7,838,531 protects therapeutic use of farnesyltransferase inhibitors, or FTIs, to reduce cellular defects associated with laminopathies and progeroid diseases. Its commercially important scope is a method-of-treatment claim directed to Hutchinson-Gilford Progeria Syndrome, or HGPS, and related disorders involving abnormal lamin farnesylation, particularly defective lamin A processing.

The patent does not claim an FTI compound, a pharmaceutical composition, a formulation, a dosing regimen, a manufacturing process, or a diagnostic test. Its value depends on whether administration of an FTI to a patient with a listed disease and the claimed cellular pathology falls within the surviving claim scope.

What does U.S. Patent 7,838,531 cover?

The patent covers two principal categories of FTI use:

Claim group	Subject of claim	Core limitation
Claims 1-5	Cellular or ex vivo treatment	Administering an FTI to a cell from a patient to reduce a listed cellular defect
Claims 6-11	Treatment of a patient	Administering an FTI to a subject who has or is predisposed to a listed disease or condition

The disease list includes:

• Hutchinson-Gilford Progeria Syndrome
• Progeria
• Emery-Dreifuss muscular dystrophy
• Limb-Girdle muscular dystrophy
• Charcot-Marie-Tooth disorder
• Werner syndrome, described as “Werner syndrome disease” in claim 6
• Dilated cardiomyopathy with conduction system disease

The cellular defects include:

• Mis-localization of a farnesylated lamin
• Mis-localization of a normally non-farnesylated lamin
• Nuclear membrane disruption
• Lamin aggregation
• Nuclear lobulation
• Nuclear blebbing
• Cytoskeleton disruption
• Early senescence
• Premature apoptosis
• Reduced secretion of MMP-3

The claims also narrow the relevant lamin to a lamin other than lamin B, and then specifically to lamin A. The claimed mechanism is therefore concentrated on aberrant farnesylation and localization of lamin A or related lamin proteins.

What are the key limitations in claim 1?

Claim 1 is an ex vivo or cell-directed method claim. It requires:

1. A cell from a subject.
2. A subject with one of the specified diseases or conditions.
3. At least one listed cellular defect.
4. Administration of a therapeutically effective dose of an FTI to the cell.

The claim is broader than the dependent claims because it does not require lamin A, a particular FTI, or a specific disease mechanism. It covers both mis-localization of farnesylated lamin and mis-localization of a normally non-farnesylated lamin.

The claim does not specify:

• The route of administration
• The dose amount
• The treatment duration
• The treatment frequency
• The formulation
• The degree of cellular improvement
• A particular mutation in LMNA
• A particular biomarker threshold
• A particular FTI concentration

The absence of a fixed dose or biomarker threshold creates breadth but may create disputes over whether a treatment was “therapeutically effective” and whether the claimed cellular defect was present.

What are the key limitations in claim 6?

Claim 6 is the principal in vivo treatment claim. It requires administration of a therapeutically effective dose of an FTI to a subject who:

• Has one of the listed diseases or conditions; or
• Is predisposed to one of those diseases or conditions.

The claim also requires reduction of at least one listed cellular defect. A patient’s disease diagnosis alone is not necessarily sufficient. The accused treatment must be connected to reduction of a claimed defect, such as nuclear blebbing, nuclear membrane disruption, premature apoptosis, or abnormal lamin localization.

The “predisposed to” language expands the claim beyond treatment of diagnosed disease. It may reach prophylactic or early-intervention treatment, but the scope would depend on proof that the subject had a meaningful predisposition and that administration reduced a claimed cellular defect.

Claim 11 states that the method treats a subject having or predisposed to the disease or condition. It adds limited practical differentiation because claim 6 already expressly covers a subject who has or is predisposed to the listed condition.

Which FTIs are expressly named in the patent claims?

Claims 5 and 10 identify five FTIs:

Compound	Claim status	Commercial relevance
PD169541	Expressly listed	Primarily research compound
R115777	Expressly listed	Tipifarnib; clinical FTI
SCH66336	Expressly listed	Lonafarnib; clinically developed FTI
L-744832	Expressly listed	Research compound
FTI-2153	Expressly listed	Research compound

The independent claims are not limited to these five compounds. Claims 1 and 6 refer generally to “a farnesyltransferase inhibitor.” A non-listed FTI could therefore fall within the independent claims if the disease, cellular defect, and therapeutic-effect limitations are satisfied.

Lonafarnib, also known as SCH66336, is the most commercially significant compound in the claim set. The FDA approved lonafarnib under the brand name Zokinvy for reducing the risk of mortality in patients with HGPS and for treatment of certain processing-deficient progeroid laminopathies in patients at least 12 months of age and meeting specified body-size criteria.[4]

Does the patent cover lonafarnib and Zokinvy?

The claims expressly identify SCH66336, the development code for lonafarnib. Lonafarnib is therefore directly implicated by dependent claims 5 and 10, in addition to the broader independent claims.

The patent’s practical coverage of Zokinvy depends on four issues:

1. The patient has HGPS or another listed laminopathy.
2. The patient has one or more claimed cellular defects.
3. Lonafarnib is administered at a therapeutically effective dose.
4. The conduct occurs during the enforceable patent term.

FDA approval does not eliminate patent risk. FDA labeling establishes regulatory authorization, while patent infringement depends on the elements of the asserted claims and the applicable statutory defenses.

The claims do not require the FDA-approved Zokinvy formulation, the approved capsule strength, a particular dosing schedule, or the FDA indication language. The patent therefore has broader drug-use language than a product-specific label claim, but the claims remain limited to specified diseases and cellular defects.

What is the patent’s legal and commercial scope?

The patent is a use patent, not a compound patent. Its commercial scope can be summarized as follows:

IP category	Coverage under U.S. 7,838,531
FTI chemical structure	No standalone composition claim
FTI treatment of listed laminopathies	Yes
HGPS treatment	Yes
Lonafarnib use	Yes, through express dependent claims and broader FTI claims
Drug formulation	No express formulation claim
Capsule, tablet, or injectable dosage form	No
Manufacturing process	No
LMNA mutation itself	No
Diagnostic method	No express diagnostic claim
Cellular assay	Potentially relevant to claims 1-5, but not claimed as a standalone assay
Generic or biosimilar product	Relevant only if its use practices the method
Non-listed disease	Generally outside the literal disease list

The patent can be infringed by treatment activity even if the FTI is lawfully manufactured and marketed for another indication. A generic or other manufacturer could face inducement issues if it markets the product with labeling that encourages a patented use. Physician or patient use may create direct infringement questions, while manufacturer liability would more commonly be analyzed under induced or contributory infringement theories under 35 U.S.C. § 271.[5]

When does U.S. Patent 7,838,531 expire?

U.S. Patent 7,838,531 was issued on November 23, 2010.[1] Its nominal patent term is tied to the applicable earliest nonprovisional filing date and is subject to any patent-term adjustment, terminal disclaimer, or other term calculation reflected in the USPTO prosecution record.

Public patent databases generally place the patent’s ordinary term in the 2025 period. The exact enforceable expiration date should be determined from the USPTO Patent Center record, including the patent-term adjustment calculation and any terminal disclaimer. A patent that has reached its statutory expiration no longer supports an infringement action for post-expiration conduct, although pre-expiration damages and other issues may remain relevant.

The patent’s age is commercially important. Even if the patent historically created a barrier to FTI treatment of progeroid laminopathies, the principal U.S. risk shifts from ordinary patent-term exclusivity to later-issued continuation patents, separate formulation patents, regulatory exclusivity, trade secrets, and market-access controls.

What is the Orange Book status of U.S. 7,838,531?

U.S. Patent 7,838,531 is a method-of-use patent rather than a compound or formulation patent. Orange Book listing depends on whether the patent was submitted for an FDA-approved drug and whether FDA accepted it as claiming the approved drug, an approved use, or a method of using the drug.[3]

For Zokinvy, the commercially relevant Orange Book analysis must be conducted against the patents submitted by the approved-drug sponsor, including any patents covering:

• Lonafarnib as a product
• Lonafarnib formulations
• Methods for treating HGPS
• Methods for treating processing-deficient progeroid laminopathies
• Dosing or administration features

The existence of U.S. 7,838,531 does not establish that it is currently listed for Zokinvy. A patent may be relevant to the drug’s historical development without appearing in the current Orange Book. An Orange Book listing also does not establish ultimate validity or infringement.

Are there Paragraph IV challenges involving this patent?

A Paragraph IV certification applies when an ANDA applicant asserts that a listed patent is invalid, unenforceable, or will not be infringed. It is relevant only if the patent is listed in the Orange Book for the reference drug.[2]

For U.S. 7,838,531, the key questions are:

Paragraph IV issue	Relevance
Is the patent listed for the reference product?	Determines whether an ANDA applicant must address it
Is the listed use included in the proposed generic labeling?	Determines potential infringement exposure
Does the patent remain unexpired?	Determines whether the patent can block launch
Does the proposed label induce the claimed use?	Central to method-patent infringement
Has a notice letter been served?	Starts the statutory litigation framework
Was a 30-month stay triggered?	Depends on the timing and listing status

The claims are vulnerable to a label-design strategy if a generic omits the patented indication and does not encourage use for HGPS or related laminopathies. That strategy is less effective if the patented indication is the principal approved use, if the label necessarily teaches the patented treatment, or if the product has limited substantial non-infringing uses.

No conclusion about a specific Paragraph IV challenge or settlement can be reached from the claim text alone. Such determinations require the FDA listing history, ANDA notices, district-court dockets, and any settlement filings.

What formulation patents protect lonafarnib and competing FTI products?

U.S. 7,838,531 does not claim a formulation. It does not protect:

• Particle size
• Salt form
• Polymorph
• Capsule shell
• Excipient combination
• Dissolution profile
• Stability package
• Pediatric liquid formulation
• Food-effect mitigation
• Manufacturing process

A commercial FTI franchise may therefore rely on a layered portfolio separate from this patent. The relevant patent categories include:

1. Composition-of-matter patents for the FTI molecule.
2. Salt, polymorph, or crystalline-form patents.
3. Pharmaceutical-composition patents.
4. Pediatric or weight-based dosing patents.
5. Method-of-use patents for HGPS or progeroid laminopathies.
6. Manufacturing and purification patents.
7. Device or packaging patents, if a specialized dosage form is used.

For lonafarnib, the strongest protection would ordinarily come from unexpired composition, formulation, or approved-use patents with claims that are difficult to avoid through label carve-outs. U.S. 7,838,531 is narrower in commercial architecture because it is limited to specified diseases and biological effects.

How strong is the patent estate for HGPS treatment?

The patent is technically strong in one respect: it connects FTI administration to a defined biological mechanism involving abnormal lamin farnesylation. HGPS is commonly associated with a pathogenic LMNA variant that produces progerin, an aberrantly farnesylated lamin A precursor. FTI treatment was developed to interfere with this processing pathway.[6,7]

Its legal strength is more mixed:

Strength factor	Assessment
Mechanistic fit to HGPS	Strong
Express coverage of lonafarnib	Strong
Coverage of listed diseases	Broad but finite
Dose specificity	Limited
Formulation protection	Absent
Biomarker specificity	Limited
Disease-definition precision	Potentially contestable
Enablement support	Dependent on specification and clinical evidence
Design-around potential	Moderate
Remaining term	Limited because of patent age

Potential validity issues could include written description, enablement, indefiniteness, anticipation, obviousness, and the scope of “therapeutically effective dose.” The dependent claims improve specificity by identifying lamin A and named FTIs, but they also narrow the available claim scope.

What litigation and settlement risks affect the patent?

The principal litigation risks are:

• A generic or sponsor challenge based on invalidity or noninfringement.
• A dispute over whether the accused patient population has a listed disease.
• A dispute over whether the treatment reduces a claimed cellular defect.
• A dispute over whether a label induces the patented use.
• A challenge to the “predisposed to” language.
• An argument that the asserted claim is directed to a natural biological correlation rather than a patent-eligible treatment method.
• A dispute over patent-term adjustment or terminal-disclaimer effects.

The patent’s claim language is less vulnerable to a pure abstractness challenge because it requires administration of a therapeutic agent to a cell or subject. The central litigation questions would more likely concern claim construction, written description, enablement, obviousness, and proof of the cellular-defect limitation.

No settlement agreement, consent judgment, or Paragraph IV resolution should be attributed to this patent without a verified docket or filing record. A settlement involving another lonafarnib patent would not necessarily resolve rights under U.S. 7,838,531.

How does U.S. 7,838,531 compare with ordinary FTI patents?

Patent type	Typical protection	Relationship to U.S. 7,838,531
Composition patent	The FTI molecule itself	Stronger against substitution and label changes
Formulation patent	Product presentation and drug delivery	Separate and absent from 7,838,531
Manufacturing patent	Production route or purification	Separate
Broad method patent	Use of an FTI for a disease	Closest category
Biomarker method patent	Patient selection or response prediction	7,838,531 includes defects but is not a standalone diagnostic claim
Pediatric dosing patent	Dose, age, weight, or schedule	Not expressly claimed
7,838,531	FTI treatment of specified laminopathies and cellular defects	Mechanism-linked use patent

What generic entry scenarios exist?

Three launch scenarios are commercially relevant.

Scenario 1: Launch after patent expiration

This is the lowest litigation-risk scenario if no related unexpired patent blocks the same indication. The generic can launch based on the approved product pathway, subject to regulatory requirements and any remaining exclusivity.

Scenario 2: Carved-label launch

An ANDA applicant may omit HGPS or another patented indication if FDA labeling permits a use carve-out and the remaining label does not encourage the patented treatment. This approach reduces method-patent risk but may limit market access.

Scenario 3: Paragraph IV launch

The applicant may challenge the patent as invalid, unenforceable, or not infringed. The commercial value of the challenge depends heavily on whether the patent is listed, whether it remains unexpired, whether the listed indication is commercially important, and whether separate patents remain in force.

For an orphan disease product, a generic may face a market with limited volume but high pricing and concentrated prescriber behavior. A carve-out can be difficult if the patented indication represents most of the product’s commercial use.

What geographic coverage does the patent provide?

U.S. 7,838,531 provides U.S. patent rights only. It does not itself establish protection in:

• Europe
• Japan
• Canada
• Australia
• China
• Other jurisdictions

International protection would depend on national patents from the relevant patent family. Foreign claim scope, expiration, prosecution history, and opposition outcomes may differ substantially. A U.S. patent expiration does not determine foreign exclusivity.

Key Takeaways

• U.S. 7,838,531 is a method-of-treatment patent covering FTIs for HGPS and specified laminopathies.
• The principal commercial target is lonafarnib, also known as SCH66336.
• Claims 1-5 focus on cells or ex vivo treatment; claims 6-11 focus on treatment of a subject.
• The claims require a listed disease or predisposition and reduction of at least one specified cellular defect.
• Lamin A and abnormal lamin farnesylation are central narrowing concepts.
• The patent does not claim lonafarnib as a compound, a formulation, a manufacturing process, or a dosage form.
• The ordinary U.S. patent term falls in the 2025 period, subject to the USPTO’s final term calculation.
• Orange Book relevance depends on actual FDA listing history, not merely on the patent’s technical relevance to Zokinvy.
• Generic risk is greatest where the proposed label includes HGPS or another listed laminopathy.
• The principal remaining commercial barriers may come from separate composition, formulation, dosing, regulatory-exclusivity, or related-use patents.

FAQs

Does U.S. 7,838,531 claim progerin directly?

No. The patent claims administration of an FTI to reduce cellular defects associated with abnormal lamin farnesylation. It does not claim the progerin protein or the LMNA mutation as a standalone invention.

Can a non-lonafarnib FTI infringe this patent?

Yes. The independent claims use the broader term “farnesyltransferase inhibitor.” The dependent claims identify specific FTIs, but the independent claims are not limited to those listed compounds.

Does the patent cover treatment of all muscular dystrophies?

No. The claims identify particular conditions, including Emery-Dreifuss muscular dystrophy and Limb-Girdle muscular dystrophy. A different muscular dystrophy would not ordinarily satisfy the express disease limitation.

Can a generic avoid the patent by changing the dose?

Possibly, but dose changes alone may not avoid the independent claims because they require a “therapeutically effective dose” rather than a specified numeric dose. A non-infringing analysis would require review of the proposed label, patient population, mechanism, and evidence of cellular-defect reduction.

Is a biosimilar analysis relevant to this patent?

Ordinarily no. Lonafarnib is a small-molecule drug, so an ANDA or other small-molecule pathway is more relevant than a biosimilar pathway. The patent can still affect generic-drug launch if the product’s labeling or use practices the claimed treatment method.

References

1. United States Patent and Trademark Office. (2010). U.S. Patent No. 7,838,531, Methods of treating laminopathies.
2. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations.
3. U.S. Food and Drug Administration. (2024). Orange Book: Approved drug products with therapeutic equivalence evaluations, patent and exclusivity information.
4. U.S. Food and Drug Administration. (2020). Zokinvy (lonafarnib) prescribing information.
5. United States Code. (2024). 35 U.S.C. § 271: Infringement of patent.
6. Gordon, L. B., Kleinman, M. E., Miller, D. T., Neuberg, D., Giobbie-Hurder, A., Gerhard-Herman, M., Smoot, L. B., Gordon, C. M., Cleveland, R. H., Nazarian, A., Stern, R. A., Maecker, H., Crigler, L., Quinn, N.,, et al. (2012). Clinical trial of a farnesyltransferase inhibitor in children with Hutchinson-Gilford progeria syndrome. Proceedings of the National Academy of Sciences, 109(41), 16666-16671.
7. Fong, L. G., Frost, D., Meta, M., Qiao, X., Yang, S. H., Coffinier, C., & Young, S. G. (2006). A protein farnesyltransferase inhibitor ameliorates disease in a mouse model of progeria. Science, 311(5767), 1621-1623.

Drugs Protected by US Patent 7,838,531

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Sentynl Theraps Inc	ZOKINVY	lonafarnib	CAPSULE;ORAL	213969-001	Nov 20, 2020		RX	Yes	No						REDUCING THE RISK OF MORTALITY IN HUTCHINSON-GILFORD PROGERIA SYNDROME (HGPS)
Sentynl Theraps Inc	ZOKINVY	lonafarnib	CAPSULE;ORAL	213969-002	Nov 20, 2020		RX	Yes	Yes						REDUCING THE RISK OF MORTALITY IN HUTCHINSON-GILFORD PROGERIA SYNDROME (HGPS)

International Family Members for US Patent 7,838,531

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Austria	547536
Australia	2003301446
Canada	2501464
European Patent Office	1552020
European Patent Office	1853265
Japan	2006507845