United States Patent 8,420,674: Pirfenidone Starter Pack Claims, Expiration, Orange Book Status, and Generic Risk
U.S. Patent No. 8,420,674 protects a structured initial-dose escalation program for pirfenidone, including a 21-day starter pack with 267-mg capsules arranged in daily blister compartments. The patent covers both the physical packaging and the method of administering pirfenidone at escalating daily doses of 801 mg, 1,602 mg, and 2,403 mg.
The patent is commercially relevant to Esbriet, the Genentech/Roche pirfenidone product approved for idiopathic pulmonary fibrosis. Its strongest protection is directed to the combination of a specific dose-escalation schedule and a corresponding package configuration. The method claims are narrower than a general pirfenidone treatment patent because they require the stated escalation sequence and are limited to fibrosis treatment.
What does U.S. Patent 8,420,674 protect?
U.S. Patent 8,420,674 protects two related subject-matter categories:
- A starter pack containing pirfenidone in a prescribed daily arrangement.
- A method for initiating pirfenidone therapy using a three-stage dose escalation.
The patent does not claim pirfenidone as a molecule. It does not broadly cover every pirfenidone formulation, every pirfenidone dose, or every treatment of pulmonary fibrosis. Its scope is tied to the regimen and packaging architecture described in the claims.
Patent identification
| Field |
Information |
| Patent number |
U.S. 8,420,674 |
| Likely title |
Methods and compositions for the treatment of fibrosis |
| Patent type |
Utility patent |
| Core active ingredient |
Pirfenidone |
| Principal commercial product |
Esbriet |
| Original commercial sponsor |
InterMune, Inc. |
| Current Roche group relationship |
Genentech/Roche |
| Issue date |
April 16, 2013 |
| Primary technology |
Dose escalation, starter packaging, fibrosis treatment |
| Principal disease focus |
Idiopathic pulmonary fibrosis |
| Relevant dosage form |
Oral 267-mg capsules or equivalent dosage forms |
| Publicly reported patent-term endpoint |
November 2, 2029, subject to applicable patent-term calculations and terminal-disclaimer limitations |
Patent records identify InterMune as the original applicant or assignee. Roche acquired InterMune in 2014, and Genentech became the principal U.S. commercial organization for Esbriet.[1]
What are the key limitations of claim 1?
Claim 1 is a combination claim requiring a highly specific starter-pack structure. It requires all of the following:
- A starter pack for an initial pirfenidone dose-escalation regimen.
- 801 mg per day on days 1 through 7.
- 1,602 mg per day on days 8 through 14.
- 2,403 mg per day beginning on at least day 15.
- Multiple compartments arranged in rows and columns.
- Separate rows for days 1 through 14.
- Three dosage columns for each day.
- One 267-mg pill in each of three daily compartments for days 1 through 7.
- Two 267-mg pills in each of three daily compartments for days 8 through 14.
- An optional additional set of compartments for days 15 through 21, with three 267-mg pills in each compartment.
The claim therefore describes a commercial starter package containing:
| Treatment period |
Daily amount |
Doses per day |
Pills per dose |
Total pills per day |
| Days 1-7 |
801 mg |
3 |
1 x 267 mg |
3 |
| Days 8-14 |
1,602 mg |
3 |
2 x 267 mg |
6 |
| Days 15-21 |
2,403 mg |
3 |
3 x 267 mg |
9 |
The first 14 days are mandatory elements of claim 1. The days 15 through 21 compartments are expressly optional. That drafting point matters because a starter pack can fall within claim 1 without including the third week of physical compartments, provided the claimed escalation regimen and first two sets of daily compartments are present.
Does claim 1 cover ordinary pirfenidone bottles?
Generally, no. A conventional bottle containing 267-mg capsules would not satisfy the claim's required row-and-column compartment arrangement merely because a physician instructs the patient to follow the same escalation schedule.
The claim focuses on a packaged presentation with:
- Separate daily rows;
- Three daily administration columns;
- Specific pill counts in each compartment; and
- A defined relationship between package layout and escalation regimen.
A bottle, pouch, or undifferentiated container is materially different from the claimed compartmentalized starter pack. Infringement would depend on the actual packaging design and labeling, not simply on the presence of pirfenidone.
What do claims 2 through 5 add?
Claims 2 through 5 narrow claim 1 through packaging configuration.
| Claim |
Added limitation |
Commercial significance |
| 2 |
A first panel for days 1-7 and a second panel for days 8-14 |
Covers a two-panel starter-pack format |
| 3 |
Compartments comprise blisters |
Directly targets blister-card packaging |
| 4 |
At least two panels with a fold between them |
Covers foldable or booklet-style configurations |
| 5 |
A casing holding several containers, each with a daily-set panel |
Extends protection to a multi-panel kit or outer case |
Claim 3 is particularly relevant to a commercial blister pack. Claims 2 and 4 provide fallback positions if a product does not use exactly the same overall casing but does use separate folded panels. Claim 5 reaches a kit containing several panel-based containers rather than a single integrated blister card.
These dependent claims also provide multiple infringement theories. A competing product could avoid claim 3 by using non-blister compartments but still face claims 2, 4, or 5 if it retains the panel and folding architecture.
What do claims 6 through 12 protect?
Claim 6 covers the treatment method rather than the package. It requires:
- Administering 801 mg per day on days 1 through 7.
- Administering 1,602 mg per day on days 8 through 14.
- Administering 2,403 mg per day from at least day 15.
- Treating a patient with a fibrosis condition.
Claim 7 limits the fibrosis condition to:
- Hermansky-Pudlak Syndrome-associated pulmonary fibrosis; or
- Idiopathic pulmonary fibrosis.
Claims 8 through 12 add administration details:
- With food;
- As multiple sub-daily dosage forms;
- Three divided doses per day;
- In capsule form;
- Each capsule containing 267 mg of pirfenidone.
Method-claim scope
The method claims are narrower than a general method-of-treatment patent. A method must satisfy the specified sequence. A regimen that begins at 267 mg three times daily, advances to 534 mg three times daily, and then reaches 801 mg three times daily would correspond to the claimed daily amounts. A regimen using a different escalation period, different pill strength, or different dosing frequency may avoid one or more dependent claims, although claim 6 does not itself require capsules, food, or exactly three daily administrations.
The method claims also raise ordinary induced-infringement issues. A generic manufacturer may not directly administer pirfenidone to patients, but prescribing information, packaging instructions, promotional materials, and physician-directed use can be relevant to whether the manufacturer induces use of the claimed regimen under 35 U.S.C. §271(b).
When does U.S. Patent 8,420,674 expire?
The public patent record reports a projected expiration date of November 2, 2029.[1] The date reflects the patent family’s priority and filing history and may be affected by patent-term adjustment, terminal disclaimers, or other statutory calculations.
The patent was issued in 2013, but its enforceable term does not ordinarily end 20 years after issuance. U.S. utility patents generally expire 20 years from the earliest effective nonprovisional filing date, subject to patent-term adjustment and patent-term extension rules under 35 U.S.C. §§154 and 156.
Exclusivity timeline
| Date |
Event |
| November 2, 2009 |
Relevant priority date reflected in public patent records |
| April 16, 2013 |
U.S. Patent 8,420,674 issued |
| October 15, 2014 |
FDA approved Esbriet for idiopathic pulmonary fibrosis |
| November 2, 2029 |
Publicly reported projected patent expiration |
| After patent expiry |
Generic entry depends on all remaining Orange Book patents, regulatory exclusivity, litigation, and settlement restrictions |
The patent’s remaining value depends on whether other Orange Book-listed patents expire earlier or later and whether generic applicants have settled Paragraph IV litigation.
What is the Orange Book status of U.S. Patent 8,420,674?
U.S. Patent 8,420,674 has been associated with the Orange Book patent estate for Esbriet, the pirfenidone product approved under NDA 208081.[2] The relevant Orange Book inquiry is not limited to whether the patent appears in a historical listing. It also requires review of:
- The current patent listing;
- The applicable use code;
- Whether the listing remains active;
- Whether the patent has been delisted;
- Any patent-term adjustment;
- FDA approval dates for generic ANDAs; and
- Litigation certifications submitted by ANDA applicants.
The patent is best characterized as a method and packaging patent rather than an active-ingredient patent. That distinction affects generic certification strategy. An ANDA applicant may challenge the patent under Paragraph IV, certify that it will wait until expiration, or attempt to carve out a patented method from its labeling where FDA regulations permit.
Which companies are challenging the Esbriet patent estate?
Public generic competition for pirfenidone has involved major manufacturers, including Teva and other ANDA sponsors. The commercial challenge has centered on the broader Esbriet patent portfolio rather than exclusively on U.S. 8,420,674.
A generic applicant can challenge the estate by filing a Paragraph IV certification asserting that a listed patent is invalid, unenforceable, or will not be infringed. The NDA holder may then bring a patent-infringement action under 35 U.S.C. §271(e)(2). Filing the action generally triggers a 30-month stay of FDA approval, subject to statutory exceptions and court action.[3]
The public record should be read at the patent-family level. A generic company that defeats or settles one Esbriet patent may still face:
- Later-expiring formulation patents;
- Method-of-use patents;
- Drug-product patents;
- Patent-term adjustments;
- Settlement restrictions; or
- Separate patents covering dosing or administration.
No single patent necessarily determines generic launch timing.
What patent litigation affects pirfenidone generic entry?
Pirfenidone litigation is likely to involve the standard Hatch-Waxman issues:
- Infringement of listed method patents;
- Validity under anticipation and obviousness;
- Written description and enablement;
- Claim construction concerning daily dosage and administration frequency;
- Induced infringement based on generic labeling;
- The scope of permissible Section viii label carve-outs;
- Patent listing disputes; and
- Settlement terms governing launch dates.
The most vulnerable technical feature is the packaging limitation. A generic manufacturer can often avoid a package claim by distributing pirfenidone in bottles or by designing a different blister layout. The method claims are more significant because an FDA-approved label may instruct patients to follow the same dose-escalation schedule.
A label that omits a patented indication or dosing instruction can reduce induced-infringement exposure. That strategy is less effective if the remaining label, physician instructions, or standard clinical use still encourage the patented method.
How strong is the patent estate for pirfenidone?
U.S. 8,420,674 has moderate strength as a standalone patent and greater value as part of the broader Esbriet estate.
Strengths
- The dosage sequence is precise and easy to identify.
- The 267-mg capsule structure corresponds to commercial Esbriet dosing.
- The method claims cover the clinically important initiation schedule.
- Dependent claims create packaging-specific fallback positions.
- The claims connect dosage escalation with a fibrosis indication.
Weaknesses
- Claim 1 is vulnerable to noninfringing packaging redesign.
- The optional third-week package limitation limits the claim’s physical scope.
- The method claims require proof that the specific escalation schedule was practiced.
- Prior-art challenges may target pirfenidone dosing, treatment of fibrosis, or dose titration.
- A generic company may use a bottle or alternative starter presentation.
- The method claims do not broadly cover every pirfenidone treatment.
The patent is stronger against a generic that copies the branded starter-pack format and uses identical dosing instructions. It is weaker against a manufacturer that sells standard bottles, relies on a different packaging design, or uses a label that lawfully omits the patented method.
What formulation and manufacturing barriers remain?
U.S. 8,420,674 is not primarily a formulation or manufacturing patent. It does not broadly protect:
- Pirfenidone synthesis;
- A particular crystalline form;
- A novel excipient system;
- A sustained-release formulation;
- A transdermal or injectable product;
- A manufacturing process; or
- A general 267-mg oral capsule.
Manufacturing barriers therefore arise mainly from regulatory quality requirements, bioequivalence, dissolution performance, content uniformity, and supply-chain controls rather than from the claims of this patent.
A generic manufacturer can generally pursue an equivalent oral product if it satisfies FDA requirements under the ANDA pathway. The commercial barrier is the need to demonstrate pharmaceutical equivalence and bioequivalence while managing any remaining Orange Book patents.
How does U.S. 8,420,674 compare with a broad pirfenidone method patent?
| Issue |
U.S. 8,420,674 |
Broad pirfenidone method patent |
| Subject matter |
Starter pack and dose escalation |
Treatment or use of pirfenidone |
| Packaging required |
Yes, for claim 1 |
Usually no |
| Specific dose sequence |
Yes |
May be broader or different |
| IPF coverage |
Yes, through dependent method claims |
May cover IPF directly |
| HPS coverage |
Yes, through claim 7 |
Depends on claim language |
| Generic design-around potential |
Relatively high for packaging |
Depends on label and indication |
| Main enforcement theory |
Direct package infringement and induced method infringement |
Method infringement, often induced infringement |
The patent’s business value comes from its fit with the branded initiation experience. It protects how therapy is introduced, not the fundamental active ingredient.
What generic launch scenarios exist?
Three principal launch scenarios apply:
- Full-label launch after patent expiry. The generic adopts the complete FDA-approved pirfenidone labeling after the relevant patent barriers expire.
- At-risk launch. The generic launches before final resolution of litigation, accepting potential damages and an injunction risk.
- Restricted-label launch. The generic omits a patented method or indication under a Section viii strategy, if FDA and patent-law requirements permit.
For this patent, a restricted-label strategy may be more practical than a physical-package challenge because the package claim can often be avoided through design. The method claims remain relevant if the generic label instructs the same three-stage titration regimen.
Key Takeaways
- U.S. Patent 8,420,674 protects a pirfenidone starter pack and a three-stage initial dose-escalation regimen.
- Claim 1 requires a detailed compartment layout, daily rows, three dosing columns, and specified 267-mg pill counts.
- Claims 6 through 12 protect administration of 801 mg, 1,602 mg, and 2,403 mg daily for fibrosis patients.
- The patent is associated with the Esbriet Orange Book estate.
- Public patent records report a projected expiration date of November 2, 2029.
- The packaging claims are comparatively easy to design around.
- The method claims create greater generic risk because FDA labeling may reproduce the patented dose-escalation instructions.
- The patent does not claim pirfenidone itself, a broad formulation, or a manufacturing process.
- Generic launch timing depends on the entire Esbriet patent portfolio, Paragraph IV litigation, FDA approvals, and any settlement agreements.
FAQs
Does U.S. Patent 8,420,674 cover pirfenidone capsules sold in ordinary bottles?
No. The principal packaging claim requires a defined compartmentalized arrangement. Ordinary bottles generally do not satisfy those structural limitations.
Does the patent cover the standard Esbriet 267-mg capsule?
Not by itself. A 267-mg capsule is one element of the dependent method claims, but the patent does not broadly claim every 267-mg pirfenidone capsule.
Can a generic manufacturer avoid the patent by using a different starter-pack design?
Potentially. A different package may avoid claims requiring specific rows, columns, panels, folds, blisters, or casings. The method claims must still be analyzed separately.
Is Hermansky-Pudlak Syndrome treatment approved under the Esbriet label?
The patent expressly identifies HPS-associated pulmonary fibrosis in claim 7. Patent coverage and FDA-approved labeling are separate issues. A patented use is not necessarily an FDA-approved indication.
What is the principal infringement risk for a pirfenidone ANDA applicant?
The principal risk is induced infringement of the method claims if the generic label instructs patients to follow the claimed escalation schedule. Packaging infringement is more dependent on the actual commercial presentation.
References
- United States Patent and Trademark Office. (2013). U.S. Patent No. 8,420,674, methods and compositions for the treatment of fibrosis. https://patents.google.com/patent/US8420674B2/en
- U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book. https://www.accessdata.fda.gov/scripts/cder/ob/
- U.S. Food and Drug Administration. (n.d.). Abbreviated new drug application submissions and the Hatch-Waxman Amendments. https://www.fda.gov/drugs/abbreviated-new-drug-application-anda/anda-submissions-refuse-receive
- U.S. Food and Drug Administration. (2014). FDA approves Esbriet to treat idiopathic pulmonary fibrosis. https://www.fda.gov/news-events/press-announcements/fda-approves-esbriet-treat-idiopathic-pulmonary-fibrosis
- Legal Information Institute. (n.d.). 35 U.S.C. §§ 154, 156, 271, and 271(e)(2). Cornell Law School. https://www.law.cornell.edu/uscode/text/35
