United States Patent No. 8,318,780: Scope, Claim Architecture, and Competitive Landscape
US Patent 8,318,780 protects a specific administration strategy for pirfenidone (pirfenidone) in patients who also need a CYP1A2 inhibitor. The core protected concept is avoiding or discontinuing concomitant use of a moderate-to-strong CYP1A2 inhibitor that also inhibits at least one additional CYP enzyme selected from CYP2C9, CYP2C19, CYP2D6, coupled with administration of pirfenidone at defined dosing regimens (including 1600 mg/day and 2400 mg/day, with a narrower numeric option at 2403 mg/day).
What does the invention claim protect?
The patent claims method-of-use protection. It is not a composition claim on pirfenidone itself, and it is not limited to a specific pirfenidone formulation. Instead, it protects a clinician and regimen-level decision:
- Give pirfenidone at a therapeutically effective amount (with multiple dependent dosing constraints).
- For patients who need therapy with a CYP1A2 inhibitor that is also a moderate-to-strong inhibitor of CYP1A2 and another CYP among CYP2C9/CYP2C19/CYP2D6, the protected method requires:
- Avoid concomitant use of that inhibitor during pirfenidone therapy; and/or
- Discontinue the inhibitor starting from a defined pre-initiation window (claim set for discontinuation).
Claim-set split: “Avoid” vs “Discontinue”
- Claim 1 family (avoid concomitant use): prevents overlap of the relevant dual-inhibitor with pirfenidone.
- Claim 11 family (discontinue): allows switching off the inhibitor prior to pirfenidone start with timing windows.
Treatment context anchors
The patent tightens in dependent claims to:
- Anti-fibrotic agent need (claim 3, claim 15)
- Idiopathic pulmonary fibrosis (IPF) (claim 4, claim 16)
- Standard pirfenidone daily dosing schedules (claims 5-10, 17-23, and claim 24)
How broad are the independent claims (claims 1 and 11)?
Claim 1 (avoid concomitant use)
Claim 1 requires the following elements, all of which must be satisfied:
- Method of administering pirfenidone to a patient in need thereof
- Therapeutically effective amount of pirfenidone
- The method must include avoiding concomitant use of a CYP1A2 inhibitor that:
- is a moderate to strong inhibitor of both
1) CYP1A2, and
2) another CYP enzyme from CYP2C9, CYP2C19, CYP2D6
- The patient is also in need of said CYP1A2 inhibitor
This is broader than “IPF-only” because it begins with “a patient in need thereof,” and only later narrows to IPF in dependent claims.
Claim 11 (discontinue prior to pirfenidone)
Claim 11 has the same pharmacology anchor (dual inhibition: CYP1A2 + one of CYP2C9/2C19/2D6), but the operational step differs:
- Administer pirfenidone
- The patient is in need of therapy with the dual-inhibitor
- The method includes:
- (a) discontinuing the CYP1A2 inhibitor
- (b) administering pirfenidone
Claim 11 is likely to be used in fact patterns where a prescriber cannot avoid the inhibitor entirely because the patient requires it, but the prescriber can withdraw it before initiating pirfenidone.
Structural implication
Both independent claims are method-of-treatment and hinge on a drug-drug interaction management rule. The patent’s claim scope is therefore tightly tied to:
- Whether the concomitant CYP1A2 inhibitor is “moderate to strong”
- Whether it also inhibits one of the listed CYP enzymes (CYP2C9/CYP2C19/CYP2D6)
- Whether the interaction is managed by avoidance or discontinuation
- Whether the patient is actually in need of both therapies (dual-need condition)
What do the dependent claims add (dosing, indication, timing)?
Indication narrowing
- Claim 3: patient is in need of an anti-fibrotic agent
- Claim 4: patient has idiopathic pulmonary fibrosis (IPF)
- Claim 15: mirrors anti-fibrotic agent
- Claim 16: mirrors IPF for the discontinuation claim set
Practical effect: If the clinical reality fits IPF, the narrower claims provide an additional infringement pathway and a stronger narrative of clinical need.
Dosing narrowing
Pirfenidone dosing appears as key numeric anchors:
| Claim(s) |
Total daily dosage |
Schedule |
| 5, 6, 17, 22 |
about 1600 mg/day |
(not always specified) |
| 8, 18 |
about 2400 mg/day |
(not always specified) |
| 9, 19, 23, 24 |
2403 mg/day |
depends on claim |
| 7, 10, 20, 21 |
“three times per day” |
tied to specific dependent claims |
| 24 |
2403 mg/day, three times/day, and CYP avoidance/discontinuation rule |
fully specified bundle |
Notable structure: Claim 24 “bundles” the tightest package:
- IPF
- pirfenidone 2403 mg/day
- three times/day
- avoiding or discontinuing the specified dual-inhibitor
- patient is also in need of that inhibitor
Timing narrowing for discontinuation
Timing is explicitly claimed only in the discontinuation line:
| Claim(s) |
Discontinuation window before pirfenidone start |
| 12 |
within 1 month prior |
| 13 |
within 2 weeks prior |
These provide gradations: a wide window (1 month) and a tighter window (2 weeks). Claim 11 already requires discontinuation; these claims set factual timing boundaries.
Claim-by-claim scope map
Claim set: avoid concomitant use
- 1. Independent: avoid concomitant CYP1A2 inhibitor (moderate-to-strong, dual inhibition with CYP2C9/2C19/2D6) while giving pirfenidone
- 2. Explains purpose: avoid adverse drug interaction with pirfenidone
- 3. Anti-fibrotic agent need
- 4. IPF
- 5. pirfenidone total daily dosage about 1600 mg
- 6. claim 3 + about 1600 mg
- 7. claim 5 + three times per day
- 8. total daily dosage about 2400 mg/day
- 9. total daily dosage 2403 mg/day
- 10. claim 9 + three times per day
Claim set: discontinue prior to pirfenidone
- 11. Independent: discontinue the dual-inhibitor and administer pirfenidone
- 12. discontinue within 1 month
- 13. discontinue within 2 weeks
- 14. purpose: avoid adverse drug interaction with pirfenidone
- 15. anti-fibrotic agent need
- 16. IPF
- 17. total daily dosage about 1600 mg
- 18. total daily dosage about 2400 mg/day
- 19. total daily dosage 2403 mg/day
- 20. claim 17 + three times per day
- 21. claim 19 + three times per day
- 22. claim 16 + about 1600 mg
- 23. claim 16 + 2403 mg/day
- 24. IPF + 2403 mg/day + three times/day + avoiding or discontinuing dual-inhibitor when patient needs it
What is the practical infringement trigger?
The infringement trigger is the combination of three factual variables:
- Drug identity: pirfenidone administered.
- Patient need condition: patient is also in need of a CYP1A2 inhibitor.
- Inhibitor pharmacology and overlap management:
- The inhibitor is a moderate to strong CYP1A2 inhibitor and also inhibits at least one of CYP2C9, CYP2C19, CYP2D6
- The prescriber either:
- avoids concomitant use during pirfenidone therapy (claim 1) or
- discontinuers it before initiating pirfenidone with defined timing (claim 11, 12, 13)
- Claim 24 requires the tightest bundle (IPF + 2403 mg/day + three times/day + avoidance/discontinuation).
How to read the claim language: “moderate to strong” and “another CYP enzyme”
“Moderate to strong inhibitor”
The claims do not define the threshold numerically in your excerpt. In practice, these terms typically track pharmacology categorizations from regulatory or literature sources used by patent drafters and later claim construction.
“Another CYP enzyme selected from…”
This is a set limitation with “and/or” logic built into the claim:
- The inhibitor must inhibit CYP1A2 and also inhibit at least one of:
This creates a landscape where some CYP1A2 inhibitors fall outside the scope if they are weak on those other pathways.
Patent landscape: how this claim strategy sits in the piracy map
Given the absence of prosecution history and bibliography in the prompt, the landscape can only be mapped at a functional level based on the claim architecture itself: this is an interaction-management method patent.
Where similar patents typically cluster (functional families)
- CYP interaction management for drug metabolism-sensitive therapies
- Method claims controlling concomitant medications based on CYP inhibition patterns
- Indication-specific tightening
- Dependent claims that lock to IPF
- Dose regimen locking
- Daily dose targets and administration frequency constraints (not just “effective amount”)
Competitive consequence
A generic or follow-on developer has two main pathways to mitigate risk:
- Design around the CYP inhibitor class by changing the rule:
- use a different dosing/interactions strategy that does not require avoiding the specific dual-inhibitor profile; or
- Design around the clinician protocol by not practicing the avoidance/discontinuation method steps
However, because the claims are method-of-use, generic manufacture alone is unlikely to be the infringement act. Infringement typically requires that a patient is treated in the manner claimed, or that an inducement theory exists for practicing clinicians.
Claim strength indicators from your set
Key features that typically increase enforceability and practical leverage:
- Clear mechanistic anchor: CYP1A2 + a second CYP (CYP2C9/2C19/2D6)
- Action constraint: “avoid concomitant use” and “discontinuing” steps are explicit
- Timing boundaries: 2 weeks and 1 month windows (for discontinuation) add factual manageability
- Dose specificity: 1600 mg/day, 2400 mg/day, and the precise 2403 mg/day appear multiple times
- IPF tie-in: dependent claims establish a clinically mapped use case
Who is most exposed operationally (commercial and medical programs)?
Highest exposure scenarios
- IPF treatment programs where concomitant therapies include a dual inhibitor of the required CYP sets and clinicians must manage interaction risk.
- Formularies and medication management workflows where the same patient may receive:
- a CYP1A2 inhibitor that also hits CYP2C9/2C19/2D6
- pirfenidone at regimens including 1600 mg/day or the 2403 mg/day schedule
Lower exposure scenarios (design-outs)
- Patients on a CYP1A2 inhibitor that does not reach “moderate to strong” inhibition or does not inhibit any of CYP2C9/2C19/2D6 with the required potency profile.
- Regimens that do not follow the claim’s avoidance/discontinuation logic.
Key Takeaways
- US 8,318,780 protects a pirfenidone administration method that requires avoiding or discontinuing a moderate-to-strong CYP1A2 inhibitor that also inhibits CYP2C9, CYP2C19, and/or CYP2D6, when the patient needs that inhibitor.
- The claims split into two operational approaches:
- Avoid concomitant use (claim 1 family)
- Discontinue prior to starting pirfenidone, with explicit windows (claim 11 family; 1 month and 2 weeks)
- Dependent claims lock in practical bundles by adding:
- IPF indication
- Dose targets, especially 1600 mg/day and 2403 mg/day
- Three-times-per-day administration
- A tight overall package in claim 24: IPF + 2403 mg/day + three times/day + avoidance/discontinuation rule
- The enforceability leverage comes from the tight pairing of drug metabolism scope (CYP inhibitor profile) with clinical action (avoid/discontinue) and regimen specificity (dosing and timing).
FAQs
1) Is this patent about pirfenidone compositions or dosing protocols?
It is about method-of-administering pirfenidone protocols, not a composition of matter. The claim center is interaction management tied to specific CYP inhibitor profiles.
2) What is the key CYP biology condition in the claims?
The patient needs a CYP1A2 inhibitor that is a moderate-to-strong inhibitor of CYP1A2 and also inhibits at least one of CYP2C9, CYP2C19, CYP2D6.
3) Does the patent require IPF for all claims?
No. IPF appears in dependent claims. The independent claims start with a broader “patient in need thereof” concept.
4) What dosing numbers are specifically claimed?
The set includes about 1600 mg/day, about 2400 mg/day, and 2403 mg/day; several dependent claims also require three times per day.
5) How do claims 1 and 11 differ practically?
Claim 1 requires avoiding concomitant use of the dual-inhibitor with pirfenidone. Claim 11 requires discontinuing the inhibitor before administering pirfenidone, with additional dependent claims defining a 1 month or 2 weeks pre-initiation window.
References (APA)
- United States Patent No. 8,318,780. (n.d.). Method of administering pirfenidone in patients requiring CYP1A2 inhibitors that also inhibit other CYP enzymes. [Patent claims as provided in prompt].
