United States Patent 8,722,693 Scope and Claim Analysis (R)-3-(4-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-1H-pyrazol-1-yl)-3-cyclopentylpropanenitrile Phosphoric Acid Salt
Executive summary: US 8,722,693 claims a specific chiral small-molecule (R)-nitrile core as a phosphoric acid salt, and extends claim scope into (i) drug product formulations with pharmaceutically acceptable carriers, (ii) oral/tablet use, and (iii) crystalline salt form, explicitly limiting the crystalline salt to a 1:1 stoichiometric salt ratio (drug base:phosphoric acid). The claim set is structurally tight on the exact active and exact counterion (phosphoric acid) and is narrowed further by chirality (R) and, for the crystalline claims, by crystal salt stoichiometry. As a result, the enforceable “design-around” surface is mainly the salt form (different counterion, different stoichiometry, or non-salt forms) and the solid-state form if the crystalline definition is construed narrowly.
What is US Patent 8,722,693 protecting: the phosphoric acid salt, the crystalline form, or the tablet formulation?
Direct answer: US 8,722,693 protects:
- The active ingredient as a specific salt: (R)-3-(4-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-1H-pyrazol-1-yl)-3-cyclopentylpropanenitrile phosphoric acid salt (claims 1, 2 depending on product structure).
- A drug product containing that salt with pharmaceutically acceptable carriers (claims 2, 7).
- Oral administration and tablet dosage form for the same salt (claims 3, 4, 9, 10).
- A crystalline salt of that active-phosphoric acid salt, with explicit 1:1 stoichiometry (claims 5, 6, 8).
How claim scope is layered
- Independent claim 1: product claim to the salt itself, with chirality fixed to (R) and counterion fixed to phosphoric acid.
- Independent claim 2: drug product claim to the same salt plus a carrier, implicitly covering a broad range of oral/tablet subtypes depending on dependent claims.
- Independent claim 5: crystalline salt form (still constrained to the same active phosphoric acid salt).
- Dependent claims 6/8: fix stoichiometry at 1:1.
- Dependent claims 3/4 and 9/10: fix route and dosage form: oral and tablet.
What are the key claim elements in US 8,722,693 and how do they narrow infringement risk?
Direct answer: The claims require cumulative identity on these axes:
1) Exact stereochemistry: “(R)”
- Claim 1 and the downstream salt claims require the active to be (R)-3-(…)-3-cyclopentylpropanenitrile.
- An accused product formulated from the (S) enantiomer or a racemate is outside literal scope for the chiral-specific claims if construed strictly.
2) Exact salt identity: “phosphoric acid salt”
- Claims require the counterion to be phosphoric acid.
- Switching to other acids (e.g., hydrochloride, methanesulfonate, fumarate, maleate) is a classic salt-form design-around if it changes the asserted “salt identity” element.
3) Crystallinity and solid-state constraints
- Claims 5 and 7 include “crystalline” salt language.
- Claim 6 and 8 further constrain the crystalline salt to a 1:1 stoichiometric ratio:
- 1:1 (R)-active base : phosphoric acid.
4) Drug product claims require a “carrier”
- Claims 2 and 7 require “a pharmaceutically acceptable carrier,” which typically encompasses excipients.
- Dependent claims narrow to oral and tablet.
5) Oral/tablet are dependent limitations
- Claims 3/4 (and 9/10) apply only when the product falls under the corresponding broader drug product claims (2 or 7). If a competitor argues non-tablet (capsule, solution, etc.), it avoids the dependent claims but may still fall into the broader “drug product” claims.
Claim-by-claim scope map for US 8,722,693 (elements, typical infringement theory, and likely design-arounds)
Claim 1
Text: “A (R)-…propanenitrile phosphoric acid salt.”
Scope: The salt as an isolated active material.
Infringement theory: sale or manufacture of the salt, regardless of dosage form.
Design-arounds:
- Different counterion (non-phosphoric acid salt).
- Different stereochemistry (non-(R)).
- Different compound (no matching base structure).
Claim 2
Text: “A drug product comprising … phosphoric acid salt and a pharmaceutically acceptable carrier.”
Scope: Any dosage form with carrier, not limited to tablet or oral in the independent claim.
Infringement theory: formulation manufacturing, sale, or import of the drug product containing the salt.
Design-arounds:
- Non-phosphoric salt.
- Carrier replacement does not avoid infringement if the salt is present; only the active salt identity matters.
Claim 3
Text: “Drug product of claim 2… suitable for oral administration.”
Scope: Route limited to oral.
Design-arounds: parenteral/non-oral delivery.
Claim 4
Text: “Drug product… in tablet form.”
Scope: Dosage form limited to tablets.
Design-arounds: capsule, film, suspension, granules, etc.
Claim 5
Text: “A crystalline … phosphoric acid salt.”
Scope: crystalline solid-state form of the salt.
Infringement theory: accused solid must be crystalline within claim construction.
Design-arounds:
- Amorphous form (if available and stable).
- Different polymorph(s) or crystal form not meeting the claim’s “crystalline salt” characterization standard.
- Potentially, a different salt stoichiometry (though the stoichiometry is separately recited in claim 6).
Claim 6
Text: “Crystalline salt… 1:1 (R)-active:phosphoric acid.”
Scope: explicit salt ratio.
Infringement theory: requires the 1:1 stoichiometric relationship for the crystalline salt.
Design-arounds:
- Non-1:1 phosphoric acid forms (hydrates, different stoichiometries).
- A different phosphoric acid salt phase with a different effective ratio.
Claim 7
Text: “A drug product comprising a crystalline … phosphoric acid salt and a pharmaceutically acceptable carrier.”
Scope: crystalline solid inside a drug product. Not limited to tablet/oral in independent claim.
Design-arounds: non-crystalline form; again, salt identity and solid state matter.
Claim 8
Text: “Drug product… crystalline salt is 1:1…”
Scope: crystalline salt inside drug product must be 1:1.
Design-arounds: same as for claim 6.
Claim 9
Text: “Drug product… suitable for oral administration.”
Scope: oral route for the crystalline 1:1-contained product class.
Design-arounds: non-oral route.
Claim 10
Text: “Drug product… in tablet form.”
Scope: tablet dosage for crystalline 1:1 salt-based products.
Design-arounds: non-tablet dosage forms.
How strong is the patent estate: what does the narrow claim structure imply for enforcement?
Direct answer: Strength is high on identity, lower on breadth.
Why enforcement can be straightforward
- The claims are “identity anchored” to:
- a specific chiral base,
- a specific acid counterion (phosphoric acid),
- a specific crystalline salt with 1:1 stoichiometry.
- For competitors using the same salt form and same solid-state characteristics, the claims can be directly relevant.
Where enforcement can be contested
- “Crystalline” and the “1:1” stoichiometry can become focal points in claim construction and proof:
- proof of crystallinity (XRD patterns, DSC behavior, particle morphology),
- confirmation of stoichiometric ratio in the solid-state salt.
Typical competitor options to reduce risk
- Swap acid to another salt.
- Use an alternate polymorph/amorphous form.
- Use a different stoichiometric form if feasible.
- Use a different dosage form to avoid dependent tablet claims (but not necessarily independent drug product claims).
What patent landscape surrounds US 8,722,693: how to map likely related intellectual property types?
Direct answer: Even without the full family disclosure here, this claim set strongly indicates a “salt/crystalline form + oral tablet” IP layer, which usually coexists with other claim types in the broader portfolio:
- Core compound claims (the free base or other salt forms of the same nitrile scaffold).
- Stereochemical claims (R-enantiomer-specific coverage).
- Other solid-state forms (polymorphs, solvates, hydrates).
- Formulation/process patents (tablet excipients, compression/drying processes, manufacturing methods).
- Regulatory-linked listing (Orange Book entries for the active salt and strength(s), and possibly method-of-use patents depending on the product’s intended indication).
Because US 8,722,693 is explicitly a phosphoric acid salt crystallinity and product claim set, it is best positioned as a late-stage “salt and form” barrier rather than a foundational “entire drug molecule” barrier.
How to interpret the claim design for landscape purposes
- If the marketed product uses this exact phosphoric acid salt and is crystalline 1:1, then:
- this patent is more likely to be directly implicated by ANDA AND Paragraph IV analyses tied to salt identity.
- If marketed products use a different salt or a non-1:1 form:
- this patent may still matter if generic challengers attempt to switch to this exact salt during development or manufacture.
When does US 8,722,693 lose exclusivity, and what generic entry risks follow?
Direct answer: Cannot be provided from the claim excerpt alone. Exclusivity and expiration depend on:
- the application filing date,
- prosecution history and any terminal disclaimers,
- patent term adjustments and PTA,
- whether patent term extension applies (rare for salt-form patents),
- whether regulatory exclusivity (e.g., NCE/NBE, pediatric, orphan) is tied to the specific product and is separate from patent term.
Because the necessary bibliographic data are not provided here, a precise expiration timeline cannot be generated.
What Orange Book status questions determine whether US 8,722,693 blocks ANDA entry?
Direct answer: Orange Book listing status is not available from the provided information. Liability in generic challenges typically follows:
- whether US 8,722,693 is listed for the relevant active ingredient salt and dosage form/strength,
- whether it is listed as a formulation patent, method-of-use patent, or drug substance/drug product patent,
- whether the ANDA “Paragraph IV” certification identifies this patent.
Without Orange Book listing data, infringement relevance by regulatory pathway cannot be mapped to a specific generic risk timeline.
What Paragraph IV claim-mapping approach would typically be used against US 8,722,693?
Direct answer: For a phosphoric acid salt patent with crystallinity and tablet dependent claims, the most common mapping focuses on three proof questions for an accused ANDA/505(b)(2) product:
- Does the product contain the same (R) phosphoric acid salt of the nitrile base?
- Is the solid-state form crystalline (and specifically, is it a crystalline 1:1 salt)?
- If the product is targeted at oral and tablets, does it fall within the tablet/oral dependent limitations (claims 3/4/9/10)?
If any one of these key identity/solid-state elements is not met, a competitor can argue lack of literal infringement. Equivalents may be argued in litigation, but crystallinity and stoichiometry are often treated as materially limiting in salt-form disputes.
How does the crystalline 1:1 limitation change the scope versus a non-stoichiometric crystalline salt claim?
Direct answer: Claim 6 and claim 8 set a stoichiometric ratio. This typically narrows the accused-structure match:
- A crystalline phosphoric acid salt that is not 1:1 (for example, a different hydrate/solvate or phase) may avoid these dependent claims even if it is crystalline and uses phosphoric acid.
- Claim 5 and claim 7 are narrower than the free salt claim but broader than the 1:1-dependent limitations because they do not explicitly recite the ratio.
Practically, if an ANDA developer makes a crystalline phosphoric acid salt that differs in stoichiometry from 1:1, claim 5/7 may still be asserted while claim 6/8 may not be. A district court could also treat stoichiometry as intrinsic to the identification of the crystalline salt, but the claim language gives the 1:1 ratio a clear role.
Key Takeaways
- US 8,722,693 is a phosphoric acid salt patent with strong identity limitations: (R) chirality and phosphoric acid.
- The claims extend to drug products containing the salt, with dependent limitations for oral administration and tablet dosage form.
- The crystalline subset (claims 5/6/7/8) adds solid-state constraints, including an explicit 1:1 stoichiometric ratio in dependent claims.
- The primary design-around levers are salt identity (acid/counterion) and solid-state/stoichiometry (crystal form, polymorph, hydrate/solvate, and whether it is truly 1:1).
FAQs
1) Does US 8,722,693 cover tablets only, or any drug product containing the salt?
The independent drug product claims (2 and 7) are not limited to tablet; tablet appears only in dependent claims (4 and 10).
2) If a generic uses a phosphoric acid salt but with different stoichiometry, which claims are most likely avoided?
The dependent claims requiring 1:1 stoichiometry (6 and 8) are most directly avoided if stoichiometry differs.
3) Can infringement occur without proving tablet form?
Yes. Claims 1 and 2 cover the salt and general drug product with carrier. Tablet form is not required for infringement of those independent claims.
4) Does the “crystalline” limitation matter if the formulation contains the correct salt?
Yes for claims 5/7/8; those require a crystalline salt, and 8 additionally requires 1:1.
5) Are method-of-use or process claims included in US 8,722,693 based on the provided text?
No. The provided claims are directed to the salt, drug product composition, and crystalline/stated dosage form limitations, not to methods of use or manufacturing steps.
References (APA)
- United States Patent 8,722,693. (Provided claim text only).
