United States Patent 8,778,947: Pirfenidone-Ciprofloxacin Dose-Adjustment Patent Analysis
U.S. Patent No. 8,778,947 protects a specific clinical-use protocol for pirfenidone when the patient receives high-dose ciprofloxacin. The patent does not claim pirfenidone as a molecule, ordinary Esbriet dosing, or every interaction with CYP1A2 inhibitors. Its central limitation is a reduction of pirfenidone dosage by approximately one-half to one-third during concomitant administration of ciprofloxacin at 750 mg twice daily.
The patent is a method-of-treatment patent associated with InterMune’s pirfenidone program. Roche acquired InterMune in 2014, and Genentech became the U.S. commercial organization for Esbriet. The patent’s commercial relevance is concentrated in prescribing information, generic labeling, physician-directed treatment, and potential induced-infringement theories rather than in pharmaceutical composition protection.
What patents protect pirfenidone-ciprofloxacin dose adjustment?
The principal protection in U.S. Patent 8,778,947 is the clinical management of increased pirfenidone exposure caused by concomitant ciprofloxacin.
| Feature |
Scope of U.S. 8,778,947 |
| Active drug |
Pirfenidone |
| Interacting drug |
Ciprofloxacin |
| Ciprofloxacin dose in core claim |
750 mg twice daily, or 1,500 mg/day |
| Pirfenidone adjustment |
Reduce by about one-half to about one-third |
| Principal disease |
Idiopathic pulmonary fibrosis, with broader disease coverage |
| Standard pirfenidone dose referenced |
2,403 mg/day or 1,800 mg/day |
| Reduced dose from 2,403 mg/day |
About 1,400 to 1,650 mg/day, optionally 1,602 mg/day |
| Reduced dose from 1,800 mg/day |
About 1,000 to 1,250 mg/day, optionally 1,200 mg/day |
| Specific regimen |
534 mg three times daily, with food |
| Dosage forms |
Capsules or tablets |
| Unit strengths |
200 mg or 267 mg |
| Patent type |
Method of treatment and drug-interaction management |
The claims are directed to treatment conduct. They require administration of pirfenidone to a patient, not merely manufacture or sale of a tablet.
How do the independent claims define infringement risk?
Claims 1, 2, and 13 are the principal independent claims.
Claim 1: dose reduction during high-dose ciprofloxacin therapy
Claim 1 requires:
- A patient with a fibrotic, inflammatory, or autoimmune disorder;
- Pirfenidone therapy;
- Concomitant ciprofloxacin at 750 mg twice daily;
- A pirfenidone dose reduction of about one-half to about one-third.
This is the patent’s primary positive-treatment claim. A regimen that continues full-dose pirfenidone while administering ciprofloxacin 750 mg twice daily would not satisfy the dose-reduction limitation of claim 1, although it could raise separate clinical and regulatory issues.
The claim is narrower than a generic “pirfenidone plus ciprofloxacin” claim. Ciprofloxacin at a different dose, another fluoroquinolone, or another CYP1A2 inhibitor would not literally satisfy the specified ciprofloxacin limitation.
Claim 2: avoiding the specified ciprofloxacin regimen
Claim 2 covers administering a therapeutically effective amount of pirfenidone while avoiding concomitant ciprofloxacin at a dose of 750 mg.
This claim does not require the express one-half-to-one-third reduction in claim 1. It targets avoidance of the specified high-dose ciprofloxacin exposure. Its practical scope depends on construction of “avoiding concomitant administration” and whether the 750 mg limitation is interpreted as a single dose or as the high-dose twice-daily regimen identified in claim 1 and the dependent claims.
Claim 13: broad disease-list implementation
Claim 13 repeats the dose-reduction protocol in claim 1 but expands the disease limitation through an extensive list. The list includes IPF, pulmonary fibrosis, autoimmune disease, inflammatory disease, renal and hepatic fibrosis, cardiovascular conditions, cancer-related conditions, neurologic disorders, infectious diseases, and other disorders.
The long disease list does not eliminate the core requirements for:
- Pirfenidone administration;
- Ciprofloxacin at 750 mg twice daily;
- Reduction of pirfenidone by approximately one-half to one-third.
The disease list expands the patient population but does not convert the patent into a general pirfenidone composition patent.
What dosage regimens are specifically protected?
Claims 3, 4, 9, 10, and 11 provide the most commercially relevant dosing limitations.
| Claim |
Protected regimen |
| Claim 3 |
Reduction from about 2,403 mg/day to about 1,400-1,650 mg/day, optionally 1,602 mg/day |
| Claim 4 |
Reduction from about 1,800 mg/day to about 1,000-1,250 mg/day, optionally 1,200 mg/day |
| Claim 9 |
534 mg three times daily, with food |
| Claim 10 |
Total daily pirfenidone dose of 1,602 mg |
| Claim 11 |
Total daily pirfenidone dose of about 1,600 mg |
| Claim 16 |
Divided administration three times daily |
| Claim 17 |
Administration with food |
| Claim 18 |
1,602 mg/day during ciprofloxacin administration |
The 1,602 mg/day regimen is commercially significant because it corresponds to two 267 mg units three times daily. The regimen is materially lower than the standard 2,403 mg/day Esbriet dose, which is three 267 mg capsules three times daily.
The claim set contains overlapping coverage. Claims 10, 11, and 18 all target approximately 1,602 mg/day. Claims 9 and 18 combine the numerical regimen with the three-times-daily administration pattern, while claims 16 and 17 add divided dosing and food administration.
What formulations are protected by U.S. Patent 8,778,947?
The patent protects use of pirfenidone in capsules or tablets under claims 7 and 8. It does not appear, from the supplied claims, to claim a particular excipient system, coating, dissolution profile, particle-size distribution, or manufacturing process.
Capsule and tablet scope
Claims 7 and 8 cover:
- Capsules;
- Tablets;
- Unit dosage forms containing 200 mg or 267 mg pirfenidone.
The 267 mg strength is the more important limitation for the 1,602 mg/day regimen. Three administrations of 534 mg require two 267 mg units per administration.
The claims do not expressly require the Esbriet trademark, a particular manufacturer, or a particular formulation technology. A generic tablet or capsule could fall within the claims if it is used in the claimed clinical regimen.
What the patent does not claim
Based on the supplied claims, U.S. 8,778,947 does not independently claim:
- Pirfenidone as a chemical compound;
- Any pirfenidone formulation without the ciprofloxacin interaction;
- A sustained-release formulation;
- A transdermal, inhaled, injectable, or other nonoral delivery system;
- A process for manufacturing pirfenidone;
- A method involving ciprofloxacin doses other than the specified dose;
- A method involving all CYP1A2 inhibitors;
- A method of treating IPF at the ordinary 2,403 mg/day dose without the ciprofloxacin limitation.
When does U.S. Patent 8,778,947 lose exclusivity?
The patent issued on July 15, 2014. Its ordinary twenty-year term is tied to the earliest effective nonprovisional priority date, not the issue date. Public patent records identify the relevant priority chain as beginning in 2009. On that basis, the expected nominal expiration is in 2029, subject to any applicable patent-term adjustment, terminal disclaimer, or regulatory patent-term extension recorded by the USPTO.
| Milestone |
Date |
| Earliest priority period |
2009 |
| Patent issued |
July 15, 2014 |
| Expected nominal term end |
2029 |
| FDA approval of Esbriet in the United States |
October 2014 |
| U.S. orphan-drug exclusivity for IPF |
Generally through October 2021 |
Patent expiration and FDA regulatory exclusivity are separate. Orphan-drug exclusivity does not extend the patent term. Conversely, a patent can remain enforceable after orphan exclusivity ends.
What is the Orange Book status of U.S. Patent 8,778,947?
U.S. Patent 8,778,947 is relevant to the Orange Book landscape for Esbriet because it claims a method of using pirfenidone for a condition treated by the approved product and addresses a clinically relevant drug interaction.
An Orange Book listing does not establish that every generic pirfenidone product infringes. It gives an abbreviated new drug application applicant a basis to make a patent certification, including a Paragraph IV certification, if the applicant seeks approval before patent expiration.
For a method-of-use patent, the principal regulatory question is whether the patent claims a use that appears in the reference listed drug’s labeling. If the patented use is included in the labeling, a generic applicant may face:
- A Paragraph IV challenge;
- A section viii statement seeking approval for nonpatented uses;
- A labeling and physician-prescribing dispute;
- Potential induced-infringement allegations if the proposed label encourages the patented regimen.
The Orange Book status should be assessed against the FDA’s current publication because listings, expiration dates, use codes, and delisting events can change. The patent itself does not establish its current listing status.
What Paragraph IV challenges affect pirfenidone?
A Paragraph IV challenge to U.S. 8,778,947 would likely attack one or more of the following elements:
- Lack of novelty based on prior disclosure of pirfenidone-ciprofloxacin coadministration;
- Obviousness based on known CYP1A2 inhibition and pirfenidone pharmacokinetics;
- Indefiniteness of “about one-half to about one-third”;
- Indefiniteness or claim-construction disputes involving “avoiding concomitant administration”;
- Written-description or enablement challenges to the extensive disease list in claim 13;
- Noninfringement based on a different ciprofloxacin dose or a noninfringing label;
- Noninfringement based on omitting the patented use from the generic label.
The strongest technical validity issue is likely obviousness. Ciprofloxacin is a known CYP1A2 inhibitor, and the label for pirfenidone identifies increased exposure and dose reduction concerns. The patent’s potential strength comes from the specific clinical translation: 750 mg twice daily and a defined pirfenidone reduction to approximately 1,602 mg/day.
The strongest infringement defense is regimen design. A generic manufacturer may seek to avoid recommending the claimed ciprofloxacin-associated regimen, although FDA labeling requirements can restrict how far a company may depart from the reference product’s safety information.
How strong is the patent estate for pirfenidone?
The estate is strongest as a narrow interaction-management patent and weaker as a broad barrier to pirfenidone competition.
| Estate component |
Strategic strength |
| Pirfenidone compound protection |
Low if relying on this patent |
| Standard IPF dosing |
Not covered by the supplied claims alone |
| Ciprofloxacin 750 mg twice daily interaction |
High relevance |
| 1,602 mg/day dose |
High specificity and commercial relevance |
| Capsule and tablet use |
Moderate |
| Broad disease list |
Broad nominal scope but vulnerable to validity and construction attacks |
| Manufacturing protection |
Not shown in the supplied claims |
| Biosimilar protection |
Not applicable |
| Generic-label risk |
Material where the patented interaction appears in labeling |
The patent’s value depends on whether generic pirfenidone products must carry instructions that practice the claimed dose reduction. A product claim is easier to enforce against manufacture and sale than a treatment-method claim. Here, liability would more likely focus on induced infringement, contributory theories, label content, or direct use by prescribing physicians and patients.
Does biosimilar risk apply to pirfenidone?
No. Pirfenidone is a chemically synthesized small molecule, not a biologic. The relevant competitors are generic applicants under section 505(j) of the Federal Food, Drug, and Cosmetic Act, not biosimilar applicants under the Public Health Service Act.
The competitive issues are therefore:
- ANDA approval;
- Paragraph IV certifications;
- section viii carve-outs;
- product labeling;
- generic substitution;
- state pharmacy-substitution rules;
- formulation and manufacturing equivalence.
Which companies challenge or compete with Esbriet?
The relevant commercial competitors fall into three groups:
Generic pirfenidone manufacturers
Generic companies can compete through ANDA approval once regulatory and patent barriers are cleared. Their risk is concentrated in the compound, formulation, and method-of-use patent portfolio, not only U.S. 8,778,947.
Alternative IPF therapies
The principal branded IPF comparator is nintedanib, marketed in the United States as Ofev by Boehringer Ingelheim. Ofev and Esbriet have different mechanisms, adverse-event profiles, dosing schedules, and patent estates.
| Product |
Active ingredient |
Manufacturer |
Core disease use |
Competitive issue |
| Esbriet |
Pirfenidone |
Genentech/Roche |
IPF |
Generic erosion and interaction-use patents |
| Ofev |
Nintedanib |
Boehringer Ingelheim |
IPF and progressive fibrosing ILD |
Separate compound, formulation, and method patents |
Pipeline therapies
New antifibrotic therapies may reduce the commercial value of a narrow dose-adjustment patent even before patent expiry if physicians shift to alternative treatment or combination regimens.
What litigation and settlement issues matter?
For U.S. 8,778,947, the critical litigation questions are not limited to whether the patent is valid. They include:
- Whether the patent is listed for a use appearing in the reference product label;
- Whether the generic label encourages the patented dosing protocol;
- Whether a section viii carve-out is accepted by FDA;
- Whether the patent holder has sued within the statutory period after a Paragraph IV notice;
- Whether a settlement permits a generic launch before patent expiration;
- Whether the settlement includes restrictions on the ciprofloxacin-associated use;
- Whether the generic product is distributed with a label that contains the claimed regimen.
A settlement can resolve commercial launch timing without validating the patent. A consent judgment or stipulated dismissal also does not establish the broader strength of the patent against nonparty generic manufacturers.
What manufacturing and geographic barriers exist?
The supplied claims do not create a manufacturing-process barrier. They apply to treatment use, dosage selection, and formulation type. A manufacturer can potentially avoid literal use-claim infringement by selling pirfenidone without promoting the patented regimen, but that strategy is constrained by FDA labeling and the product’s approved safety information.
Geographic coverage is limited to the United States. The patent does not directly block:
- Manufacture and sale outside the United States;
- Foreign use;
- Foreign regulatory approval;
- U.S. importation of products made abroad where no independent patent infringement occurs;
- Alternative regimens that do not meet the claim limitations.
Foreign equivalents may exist in the same patent family, but each country requires separate validity, term, listing, and litigation analysis.
How does U.S. 8,778,947 compare with broader pirfenidone patents?
U.S. 8,778,947 is narrower than a compound or formulation patent but more clinically specific than a general method-of-treatment patent.
| Patent category |
Typical protection |
Relative relevance to 8,778,947 |
| Compound patent |
Pirfenidone molecule |
Separate and generally broader |
| Composition patent |
Pirfenidone formulation |
Separate |
| Manufacturing patent |
Synthesis or purification |
Not present in supplied claims |
| Broad method patent |
Pirfenidone for fibrosis |
Broader disease/use concept |
| Interaction patent |
Pirfenidone dose adjustment with ciprofloxacin |
Core subject of 8,778,947 |
| Labeling patent |
Specific approved administration instructions |
Potentially overlapping commercial effect |
The patent can remain relevant after broader compound protection expires because a generic product may still need to address the patented method of use.
What generic launch scenarios exist?
Scenario 1: full-label generic launch
The generic applicant includes the ciprofloxacin interaction and dose-reduction instructions. This creates the highest induced-infringement and Paragraph IV exposure.
Scenario 2: section viii carve-out
The applicant omits the patented use while retaining nonpatented pirfenidone indications or dosing instructions. This reduces method-of-use risk but may create FDA labeling constraints.
Scenario 3: settlement-based entry
The applicant receives a negotiated launch date before the nominal patent expiration. Commercial entry then depends on the settlement terms and any remaining patents.
Scenario 4: post-expiration entry
The applicant launches after the patent expires, subject to other unexpired patents, regulatory exclusivity, and manufacturing readiness.
Key Takeaways
- U.S. Patent 8,778,947 is a method-of-treatment patent, not a pirfenidone composition patent.
- Its central claim requires pirfenidone dose reduction during ciprofloxacin 750 mg twice-daily therapy.
- The commercially important target is approximately 1,602 mg/day, commonly administered as 534 mg three times daily with food.
- Claims 2 and 13 expand the estate through avoidance language and a broad disease list.
- The patent covers capsules and tablets containing 200 mg or 267 mg pirfenidone but does not claim a specific excipient or manufacturing process.
- The expected nominal patent term extends into 2029 based on the 2009 priority period.
- Generic risk is driven by Paragraph IV certification, section viii carve-outs, and whether the FDA-approved label encourages the patented regimen.
- Biosimilar law is not relevant because pirfenidone is a small-molecule drug.
- The estate is commercially meaningful for interaction-management labeling but narrower than compound, formulation, or broad antifibrotic-use protection.
- Roche and Genentech are the principal successor commercial interests following Roche’s acquisition of InterMune.
Frequently Asked Questions
Does U.S. Patent 8,778,947 cover all ciprofloxacin use with pirfenidone?
No. The supplied claims focus on ciprofloxacin at 750 mg twice daily and require either a defined pirfenidone dose reduction or avoidance of the specified concomitant regimen.
Does the patent cover the normal 2,403 mg/day Esbriet dose?
Not by itself. The independent claims require the ciprofloxacin-related dose-adjustment or avoidance limitations.
Can a generic sell pirfenidone in 267 mg tablets?
Yes, the patent does not prohibit manufacture or sale of 267 mg tablets as such. Risk arises from using or promoting those tablets in the claimed ciprofloxacin-associated regimen.
Is 1,602 mg/day the same as 1,600 mg/day under the patent?
Claims 10 and 18 expressly identify 1,602 mg/day. Claim 11 separately covers about 1,600 mg/day. The legal effect depends on claim construction and the meaning of “about.”
Does the patent cover nintedanib or Ofev?
No. The supplied claims are directed to pirfenidone and do not cover nintedanib.
Does FDA approval prove that U.S. 8,778,947 is valid?
No. FDA approval and patent validity are separate legal questions. Regulatory labeling may create practical infringement exposure without resolving novelty, obviousness, enablement, or claim construction.
References
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U.S. Patent No. 8,778,947. (2014). Methods of administering pirfenidone. United States Patent and Trademark Office.
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U.S. Food and Drug Administration. (2023). Esbriet (pirfenidone) prescribing information. Genentech USA, Inc.
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U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations. Center for Drug Evaluation and Research.
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Roche Holding Ltd. (2014). Roche completes acquisition of InterMune. Roche.
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U.S. Food and Drug Administration. (2014). FDA approves Esbriet to treat idiopathic pulmonary fibrosis. Center for Drug Evaluation and Research.
