US Patent 8,629,162: Scope, Claims, Expiration, and Cystic Fibrosis Patent Landscape

US Patent 8,629,162 protects a narrow method of using the CFTR-modulating compound QBW251, also known as N-(5-hydroxy-2,4-di-tert-butylphenyl)-4-oxo-1H-quinoline-3-carboxamide, in patients with relatively mild or moderate cystic fibrosis phenotypes. The patent does not claim the compound itself, a formulation, a manufacturing process, or a broad class of CFTR modulators.

The claims focus on patient selection: pancreatic sufficiency, idiopathic pancreatitis, congenital bilateral absence of the vas deferens, and mild lung disease. QBW251 was investigated clinically as an oral CFTR potentiator but has not become an FDA-approved cystic fibrosis medicine. The patent therefore has limited current commercial value unless QBW251 or a closely related program is revived.

What does US Patent 8,629,162 cover?

The patent covers a treatment method using a specific chemical entity in selected cystic fibrosis patients.

The independent claim requires four elements:

A patient has a moderate-to-mild clinical phenotype of cystic fibrosis.
The patient is treated or has the severity of the disease lessened.
A pharmaceutical composition is administered.
The composition contains N-(5-hydroxy-2,4-di-tert-butylphenyl)-4-oxo-1H-quinoline-3-carboxamide.

The claim does not require a particular dose, route, formulation, treatment duration, genotype, or clinical endpoint.

Claim 1: Core method-of-use protection

Claim 1 is the commercial center of the patent. It covers administration of a composition containing QBW251 to treat or reduce the severity of mild-to-moderate cystic fibrosis.

The claim is narrower than a composition claim because infringement requires use in a patient. A party that manufactures or sells the compound without practicing the claimed treatment method would not, solely on that conduct, necessarily infringe claim 1.

The phrase “comprising” makes the composition open-ended. A composition may contain QBW251 together with excipients, carriers, additional active ingredients, or other formulation components.

The claim does not expressly limit the active ingredient to a particular polymorph, salt, solvate, particle size, or release profile. Those limitations could matter under a separate formulation or composition patent, but they are not present in claim 1.

Claims 2 through 6: Patient-subgroup limitations

Claim	Added limitation	Scope
1	Mild-to-moderate cystic fibrosis; QBW251 administration	Broadest method claim
2	Patient exhibits pancreatic sufficiency	Subgroup of claim 1
3	Patient has idiopathic pancreatitis, congenital bilateral absence of the vas deferens, or mild lung disease	Alternative diagnostic subgroups
4	Patient has idiopathic pancreatitis	Narrower species claim
5	Patient has congenital bilateral absence of the vas deferens	Narrower species claim
6	Patient has mild lung disease	Narrower species claim

Claims 2 through 6 are dependent claims. Each incorporates all limitations of claim 1. They do not create independent protection for those conditions outside the cystic fibrosis treatment context.

What is QBW251 and how does it relate to the patent?

QBW251 is a small-molecule CFTR potentiator. Its chemical name is N-(5-hydroxy-2,4-di-tert-butylphenyl)-4-oxo-1H-quinoline-3-carboxamide. The compound was studied as a potential treatment for cystic fibrosis, including patients with residual CFTR function and less severe disease phenotypes.

A potentiator increases the activity or opening probability of CFTR channels that reach the cell surface. That mechanism differs from a CFTR corrector, which is intended to improve protein folding, processing, or trafficking.

The compound is chemically distinct from:

Ivacaftor, the active ingredient in Kalydeco;
Lumacaftor, the active ingredient in Orkambi with ivacaftor;
Tezacaftor, the active ingredient in Symdeko with ivacaftor;
Elexacaftor, the principal corrector in Trikafta and Kaftrio;
Ataluren, an investigational read-through agent for selected nonsense mutations.

A claim directed to QBW251 does not read on those products merely because they are also used to treat cystic fibrosis.

How strong is the patent estate for US 8,629,162?

The patent estate is narrow as a standalone asset.

Strengths

The patent has several features that can make a method-of-use patent enforceable if the underlying product reaches the market:

It identifies a single, chemically defined active ingredient.
It targets a defined clinical population.
It includes narrower claims for pancreatic sufficiency and specific cystic fibrosis-associated conditions.
A product label that expressly directs treatment of the claimed population could create substantial inducement risk.
The compound-specific limitation reduces vulnerability to invalidity arguments based on generic CFTR-potentiator disclosures.

Limitations

The patent also has material weaknesses from a commercial perspective:

It does not claim QBW251 itself.
It does not claim a broad CFTR-potentiator genus.
It does not claim a specific dosage regimen.
It does not claim inhaled, oral, tablet, capsule, or controlled-release dosage forms.
It does not claim combination therapy with a corrector or another potentiator.
It may be difficult to prove infringement if a product label does not identify the claimed mild-to-moderate population or the listed subgroups.
The patent’s value depends on development and approval of the specific compound.

The patent would be stronger as part of a broader family containing composition-of-matter, salt, polymorph, formulation, dosing, combination, and manufacturing claims. US 8,629,162 alone does not provide that breadth.

When does US Patent 8,629,162 expire?

US Patent 8,629,162 was granted on January 14, 2014. Its enforceable term is governed by the greater of 20 years from the applicable nonprovisional filing date or the relevant international filing date, subject to patent-term adjustment and any terminal disclaimer.[1]

Public patent records associate the patent with an application family directed to cystic fibrosis treatment methods. The expected unadjusted term is in the late 2020s, generally around 2027 to 2028 depending on the controlling priority and filing dates. The exact enforceable expiration date must be taken from the USPTO patent-term calculation, including any patent-term adjustment.

No FDA patent-term extension should be assumed. A patent-term extension is generally available only for a patent covering an approved product, and QBW251 has not received FDA approval.

Event	Date or status
Patent grant	January 14, 2014
Patent type	Method-of-use patent
Active ingredient	QBW251
Expected statutory term	Late 2020s, subject to USPTO adjustment
FDA-approved product covered by the claims	None identified
Patent-term extension	No identified extension
Orange Book listing	No identified listing

What is the FDA regulatory status of QBW251?

QBW251 is not an FDA-approved drug. It was investigated in clinical studies for cystic fibrosis, including studies involving patients with residual CFTR function and less severe disease.

Because there is no approved QBW251 product:

There is no approved reference listed drug for an ANDA applicant to copy.
There is no FDA-approved label establishing the claimed indication.
There is no standard Paragraph IV pathway directed to QBW251 as an approved reference product.
There is no conventional generic-launch date tied to this patent.
The patent is not currently operating as an Orange Book barrier to an approved generic product.

The regulatory position differs from Vertex’s approved CFTR-modulator portfolio. Kalydeco, Orkambi, Symdeko, and Trikafta have approved labels and Orange Book patent listings, but their active ingredients are not QBW251.[2]

What is the Orange Book status of US 8,629,162?

US 8,629,162 is not known to be listed in the FDA Orange Book for an approved QBW251 product.

The Orange Book lists patents submitted by sponsors for approved drug products. A method-of-use patent covering an unapproved investigational compound ordinarily has no Orange Book function. The absence of an Orange Book listing means that the patent does not presently generate a conventional Paragraph IV certification dispute against an ANDA applicant for QBW251.

This does not eliminate all potential infringement risk. If a company later obtains approval for QBW251 or a product containing the claimed compound, the sponsor could seek to list eligible patents associated with the approved product, subject to FDA listing rules and the patent’s scope.

Are there Paragraph IV challenges to US 8,629,162?

No conventional Paragraph IV challenge has been identified against US 8,629,162.

Paragraph IV litigation generally requires an ANDA applicant to challenge a listed patent covering an approved reference drug. QBW251 has not established that regulatory framework. An abbreviated approval route for a future QBW251 product would depend on the regulatory status of the reference product and the applicable FDA pathway.

A future generic applicant could still challenge validity or infringement through litigation if the patent became relevant to an approved product. The principal possible grounds would include:

Lack of written description or enablement;
Obviousness based on prior CFTR-potentiator treatment disclosures;
Indefiniteness in terms such as “mild” or “moderate-to-mild” phenotype;
Noninfringement based on patient selection, labeling, or the identity of the active ingredient;
Lack of patentable distinction over earlier clinical or preclinical use disclosures.

What formulations are protected by US 8,629,162?

None are protected expressly.

The claims require a “pharmaceutical composition,” but they do not specify:

Tablet or capsule form;
Oral solution;
Inhaled formulation;
Lipid or nanoparticle delivery system;
Immediate-release or extended-release profile;
Specific excipient;
Particle size;
Salt or solvate;
Dose strength;
Fixed-dose combination.

The word “composition” supplies an administration vehicle but does not create a formulation-specific monopoly. A later formulation patent could protect a particular dosage form containing QBW251 without being duplicative of this patent, provided the formulation claims include patentably distinct limitations.

Does the patent cover combination therapy?

Potentially, but only within the limits of claim 1.

Because claim 1 uses “comprising,” a composition containing QBW251 and another active ingredient could fall within the claim if the patient and disease limitations are satisfied. The claim does not require QBW251 to be the only active ingredient.

The patent does not expressly require combination treatment with:

A CFTR corrector;
Ivacaftor;
Elexacaftor;
Tezacaftor;
Lumacaftor;
An anti-inflammatory agent;
An antibiotic.

A combination product containing QBW251 could therefore raise infringement issues under the open-ended composition language, while a separate combination patent would need additional limitations to establish independent protection.

What patent litigation affects US 8,629,162?

No material infringement litigation or Paragraph IV case involving US 8,629,162 has been identified in the standard public patent-litigation record.

The absence of litigation is consistent with the patent’s commercial position:

QBW251 is not an approved product.
No generic sponsor has an ANDA for QBW251.
The patent is not an evident Orange Book-listed barrier.
There is no established branded product revenue stream to protect.

The main legal risk is therefore prospective. It would arise if a company resumed development of QBW251, licensed the compound, or developed a product containing the claimed chemical entity.

Which companies are challenging or developing around this patent?

No active Paragraph IV challenger has been identified. The relevant competitive activity is more likely to involve development around the patent than direct litigation.

Potential design-around routes

A competitor could seek to avoid literal infringement by:

Using a different CFTR potentiator.
Modifying the QBW251 scaffold.
Developing a prodrug or salt that does not satisfy the claim’s active-ingredient limitation, subject to claim construction and conversion in vivo.
Targeting severe disease rather than the claimed mild-to-moderate phenotype.
Avoiding label language directed to pancreatic sufficiency or the listed diagnostic subgroups.
Using a separate CFTR corrector or potentiator combination.

Design-around analysis must account for the doctrine of equivalents, regulatory labeling, induced infringement, and any separate composition-of-matter patents in the same family.

How does US 8,629,162 compare with Vertex CFTR patents?

Issue	US 8,629,162	Major Vertex CFTR product patents
Protected subject matter	Patient treatment method	Composition, formulation, dosing, and method claims across product families
Active ingredient	QBW251	Ivacaftor, lumacaftor, tezacaftor, elexacaftor
FDA-approved product	No	Yes
Orange Book relevance	None identified	Material for approved products
Generic challenge exposure	No current conventional ANDA challenge identified	Paragraph IV litigation has occurred for approved CFTR products
Commercial dependence	Future development of QBW251	Existing CFTR product sales
Claim breadth	Narrow	Varies by family; generally broader portfolio protection
Biosimilar risk	Not applicable	Not applicable because these are small molecules, not biologics

A biosimilar pathway is not relevant to QBW251. QBW251 is a small molecule, so any future follow-on product would be addressed through an ANDA, 505(b)(2), or another small-molecule pathway rather than a biologics license application and biosimilar application.

What licensing deals relate to QBW251 and this patent?

Publicly disclosed development activity identifies Novartis as a company associated with QBW251 clinical development. The Cystic Fibrosis Foundation has also supported development of CFTR-modulating technologies through its translational and clinical programs.[3]

No publicly established, product-specific licensing arrangement has been confirmed as creating a current commercial obligation under US 8,629,162. Patent ownership, clinical sponsorship, development rights, and royalty rights should not be treated as identical concepts. A company may conduct clinical development under a collaboration without owning every patent in the relevant family.

For transaction diligence, the critical issues are assignment history, exclusive field-of-use rights, sublicensing rights, prosecution-control provisions, milestone obligations, and any reversion rights tied to development discontinuation.

What generic entry risks exist?

There is no immediate generic-entry risk because there is no approved QBW251 reference product.

If QBW251 were revived and approved, generic-entry risk would depend on the broader estate rather than US 8,629,162 alone. The principal scenarios would be:

Scenario	Commercial effect
Only US 8,629,162 remains enforceable	Label-based method risk, but possible noninfringing-label strategies
Composition patent remains in force	Stronger barrier against direct generic substitution
Formulation patent remains in force	Risk depends on the approved dosage form
Combination patent remains in force	Relevant only to covered fixed-dose or coadministered regimens
No surviving composition or formulation claims	Earlier generic or 505(b)(2) exposure
Patent term expires before approval	Limited value as a regulatory exclusivity asset

The patent is more valuable as a supplemental indication patent than as a standalone barrier to competition.

What is the geographic coverage of the patent?

US 8,629,162 provides protection only in the United States. Foreign protection depends on national-phase counterparts and whether those patents were granted, maintained, abandoned, or expired.

A global development or licensing review should separate:

United States method claims;
European Patent Convention counterparts;
Canadian claims;
Japanese claims;
Australian claims;
China and other major-market national patents;
Patent term, annuity, and opposition status in each jurisdiction.

The US patent cannot be used to block use, sale, or manufacture outside the United States. Parallel foreign rights may differ materially in claim scope and expiration.

What manufacturing and intellectual-property barriers apply?

US 8,629,162 does not claim a manufacturing process. It therefore creates no direct process monopoly for synthesizing QBW251.

Manufacturing risk may instead arise from:

Separate process patents;
Crystalline-form or polymorph patents;
Impurity-control patents;
Intermediate patents;
Scale-up and purification know-how;
Regulatory specifications;
Supply-chain control of key intermediates.

The compound’s multiple tert-butyl and hydroxy substituents may create process-development and impurity-control requirements, but those technical issues are not limitations in the issued claims. A manufacturer could face separate patent or trade-secret barriers even if it avoids infringement of US 8,629,162.

Key Takeaways

US 8,629,162 is a narrow cystic fibrosis method-of-use patent.
It covers treatment with QBW251, not the compound itself.
The claims target mild-to-moderate cystic fibrosis and selected patient subgroups.
Claims 2 through 6 narrow the patient population but do not expand the disease indication.
No formulation, dose, route, combination, manufacturing, or polymorph is expressly claimed.
QBW251 is not FDA approved, and the patent has no identified current Orange Book role.
No conventional Paragraph IV challenge has been identified.
Biosimilar analysis is irrelevant because QBW251 is a small molecule.
The patent’s expected term is in the late 2020s, subject to USPTO patent-term adjustment and the controlling priority date.
The patent has limited standalone commercial strength without surviving composition or formulation patents.
Its value would increase materially if QBW251 were revived, approved, and labeled for the claimed patient population.

FAQs About US Patent 8,629,162

Is US 8,629,162 a composition-of-matter patent?

No. It is a method-of-treatment patent. It requires administration of a pharmaceutical composition containing QBW251 to a qualifying cystic fibrosis patient.

Does US 8,629,162 cover ivacaftor or Trikafta?

No. The claims identify QBW251 by chemical identity. Ivacaftor, lumacaftor, tezacaftor, and elexacaftor are different compounds.

Can a generic avoid the patent by changing the formulation?

Changing the formulation may avoid limitations that are absent from the patent, but it would not necessarily avoid claim 1 if the product still contains QBW251 and is used for the claimed patient population.

Does pancreatic sufficiency have to be present for every claim?

No. Pancreatic sufficiency is required only by claim 2. Claims 1 and 3 through 6 do not require that limitation unless they are being practiced together with claim 2.

Could a 505(b)(2) applicant face this patent?

Yes. A 505(b)(2) applicant could face patent risk if its product contains QBW251 and its proposed labeling or promotion falls within the claimed cystic fibrosis treatment method. The pathway itself does not eliminate method-of-use infringement risk.

References

United States Patent and Trademark Office. (2014). US Patent No. 8,629,162, methods of treating cystic fibrosis.
U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book.
Cystic Fibrosis Foundation. (n.d.). Drug development and CFTR modulator research programs.
ClinicalTrials.gov. (n.d.). Studies of QBW251 in patients with cystic fibrosis. National Library of Medicine.

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
European Patent Office	1773816	⤷ Start Trial	C300748	Netherlands	⤷ Start Trial
European Patent Office	1773816	⤷ Start Trial	CA 2015 00038	Denmark	⤷ Start Trial
European Patent Office	1773816	⤷ Start Trial	PA2015028	Lithuania	⤷ Start Trial
European Patent Office	1773816	⤷ Start Trial	C20150028 00162	Estonia	⤷ Start Trial
European Patent Office	1773816	⤷ Start Trial	1590036-8	Sweden	⤷ Start Trial
European Patent Office	1773816	⤷ Start Trial	15C0045	France	⤷ Start Trial
European Patent Office	1773816	⤷ Start Trial	92761	Luxembourg	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 8,629,162

Summary for Patent: 8,629,162