United States Patent 6,956,041: Scope, Claim Architecture, and US Landscape Impact
US Patent 6,956,041 defines a tightly scoped JAK3-targeting small-molecule composition and method set centered on a common heteroaryl-piperidine scaffold (pyrrolo[2,3-d]pyrimidine core) and extends the composition claim to combination regimens. The independent claim set covers multiple named compounds (and salts) in a “compound-selected-from-a-list” format, plus a single dependent narrowing to the nitrile analog “3-{4-Methyl-3-[methyl-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-amino]-piperidin-1-yl}-3-oxo-propionitrile.” A separate method claim expressly recites inhibition of JAK3 via administration of the same listed compounds, with another dependent narrowing to the same nitrile analog.
This architecture has three practical consequences for the US patent landscape: (1) claim scope is broad as to which members of the list infringe, but narrow as to structure space outside the list; (2) the method claim is framed at the target level (JAK3 inhibition), which can support infringement theories tied to functional performance if an accused compound is within the enumerated set; and (3) the composition claim can expand blocking coverage into combination therapy use-cases by listing multiple immunosuppressive agents and anti-inflammatory drugs as “additional agents.”
What is the core claimed subject matter?
What does claim 1 cover? (composition + carrier)
Claim 1 is a pharmaceutical composition defined by:
- A therapeutically effective compound selected from the enumerated group of eight named structures (plus pharmaceutically acceptable salts)
- A pharmaceutically acceptable carrier
Enumerated compound set in claim 1 (8 members):
- Methyl-[4-methyl-1-(propane-1-sulfonyl)-piperidin-3-yl]-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-amine
- 4-Methyl-3-[methyl-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-amino]-piperidine-1-carboxylic acid methyl ester
- 3,3,3-Trifluoro-1-{4-methyl-3-[methyl-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-amino]-piperidin-1-yl}-propan-1-one
- 4-Methyl-3-[methyl-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-amino]-piperidine-1-carboxylic acid dimethylamide
- 3-{4-Methyl-3-[methyl-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-amino]-piperidin-1-yl}-3-oxo-propionitrile
- 3,3,3-Trifluoro-1-{4-methyl-3-[methyl-(5-methyl-7H-pyrrolo[2,3-d]pyrimidin-4-yl-amino]-piperidin-1-yl}-propan-1-one
- 1-{4-Methyl-3-[methyl-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-amino]-piperidine-1-yl}-but-3-yn-1-one
- 1-{3-[(5-Chloro-7H-pyrrolo[2,3-d]pyrimidin-4-yl)-methyl-amino]-4-methyl-piperidin-1-yl}-propan-1-one
- 1-{3-[(5-Fluoro-7H-pyrrolo[2,3-d]pyrimidin-4-yl)-methyl-amino]-4-methyl-piperidin-1-yl}-propan-1-one
Note on enumeration: your provided claim text states “a compound selected from the group consisting of:” and then lists these named members. In the provided claim statement, the list contains the eight core examples plus the two halogenated 5-substituted pyrrolo[2,3-d]pyrimidine members and one additional fluorinated/trifluorinated member. The scope is controlled by the literal list as provided in the claim.
Definition-level consequence: Because claim 1 uses an “X selected from the group consisting of …” construction, infringement by a competitor is largely binary: either the accused compound is literally one of the listed structures (or a salt form), or it is outside claim 1. Functional equivalence is less likely to expand scope beyond the literal list.
What is claim 2 adding? (dependent narrowing)
Claim 2 narrows claim 1 by specifying:
- The compound is 3-{4-Methyl-3-[methyl-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-amino]-piperidin-1-yl}-3-oxo-propionitrile, or its salt
- Still includes the pharmaceutically acceptable carrier
Practical implication: claim 2 targets the nitrile analog as the “preferred” or “anchor” member. If an accused product uses that exact nitrile structure, the claim narrows cleanly to a single compound identity.
What does claim 3 add? (combination therapy composition)
Claim 3 modifies claim 1 by adding:
- “Further comprising one or more additional agents”
- The additional agent(s) are selected from a listed regimen including immunosuppressants, biologics, and NSAIDs/anti-inflammatory steroid.
Additional agents in claim 3:
- Cyclosporin A
- Rapamycin
- Tacrolimus
- Leflunomide
- Deoxyspergualin
- Mycophenolate
- Azathioprine
- Daclizumab
- Muromonab-CD3
- Antithymocyte globulin
- Aspirin
- Acetaminophen
- Ibuprofen
- Naproxen
- Piroxicam
- Anti-inflammatory steroid
Key scope point: Claim 3 does not define the therapeutic indication. It blocks “composition + carrier + one of the listed additional agents” use-cases for compositions containing one of the claim 1-listed JAK3 inhibitors. That means the landscape risk is not just the molecule, but also combination dosing and labeling.
What does claim 4 cover?
What does claim 4 add? (JAK3 inhibition method via administration)
Claim 4 shifts from composition to method:
- “A method for the inhibition of Janus Kinase 3 (JAK3) in a mammal, including a human”
- Comprising administering an effective amount of one of the same enumerated listed compounds (or salt)
This is a classic method-of-use claim tied to a mechanism statement (JAK3 inhibition) and a defined administration of specific chemical entities.
Method compound set in claim 4: mirrors the list in claim 1, with the same nitrile dependent fallback.
What does claim 5 add? (dependent method narrowing)
Claim 5 narrows claim 4 to:
- the nitrile analog: 3-{4-Methyl-3-[methyl-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-amino]-piperidin-1-yl}-3-oxo-propionitrile, or its salt
Claim scope mapped to infringement scenarios
How would scope behave against an accused competitor molecule?
Because both composition and method claims depend on a “selected from” list, the highest-probability infringement hinges on literal structural match to one of the enumerated members.
| Claimed element |
What triggers coverage |
What breaks coverage |
| Compound identity (claims 1 and 4) |
Accused compound is literally one of the listed members (or a pharmaceutically acceptable salt) |
Structural variant outside the enumerated list |
| Carrier (claim 1) |
Formulation includes a pharmaceutically acceptable carrier with the listed compound |
Formulation avoids carrier claim language (rare in practice) |
| Combination addition (claim 3) |
Formulation includes one of the enumerated “additional agents” with the listed compound |
Using agents not on the claim list, or non-combination dosing strategies |
| Target statement (claims 4 and 5) |
Accused product contains one of the listed compounds and is administered to inhibit JAK3 |
Accused compound not on list; target statement does not rescue an off-list molecule |
Where combination therapy can expand practical landscape risk (claim 3)
Claim 3 creates landscape pressure on:
- Co-formulation products that include one of the listed additional agents
- Labeling and medical-use cases that combine the JAK3 inhibitor with one of the specified immunosuppressants or anti-inflammatory agents
The claim does not limit route, timing, or dose ratio; it requires that the composition “further comprising one or more additional agents” is used.
Structural theme and what it implies for “design-around”
What chemical motifs are repeatedly present in the list?
Across the enumerated compounds, the common motifs include:
- A 7H-pyrrolo[2,3-d]pyrimidine core substituted at the “4-yl” position by an amino linkage to a piperidine system
- A piperidine substituted with “4-methyl” and a “3-yl methylamino” style linkage as reflected in the named groups
- Variations at the piperidine N-substituent or appended functional groups:
- sulfonyl propyl group (propane-1-sulfonyl)
- carboxylate ester / dimethylamide at a carboxylic position
- trifluoromethyl-propanone motifs
- nitrile-propanone analogs (propionitrile)
- alkynone “but-3-yn-1-one” motif
- 5-chloro and 5-fluoro substitutions on the heteroaryl ring via a methyl-amino linkage
Design-around consequence: A competitor seeking to avoid these claims needs to avoid literal coverage of each member in the enumerated list. Changing the scaffold outside the named structures is more reliable than trying to rely on different substituent classes, since the claims name exact molecules rather than broad functional classes.
Patent landscape positioning for US 6,956,041 (how it typically functions in enforcement)
How this patent likely acts in the US portfolio
Given its claim focus, the patent typically functions as:
- A compound-plus-formulation barrier for the enumerated members (claim 1)
- A single-preferred compound barrier for the nitrile analog (claims 2 and 5)
- A combination therapy blocker for products combining with a broad list of immunosuppressants and anti-inflammatory agents (claim 3)
- A method-of-use hook that can attach to clinical use and promotional labeling for JAK3 inhibition when the administered molecule is one of the listed compounds (claims 4 and 5)
Landscape risk tends to concentrate in:
- Products using the nitrile analog (because dependent claims narrow to it)
- Programs pursuing JAK3 inhibition within the same structural series
- Combination regimens with immunosuppressants and NSAIDs as listed in claim 3
What are the actionable claim-limitations?
Where the patent is narrow
- Enumerated compound list constraint: scope is limited to the specific named chemical entities and salts.
- Carrier/administration framing: while broadly phrased, it still depends on a pharmaceutical composition/method structure.
Where the patent is broad
- Multiple compounds included in one claim: claim 1 and claim 4 cover a set of related structures.
- Combination agent list: claim 3 expands to multiple mechanistically diverse co-therapies (calcineurin inhibitors, antiproliferatives, biologics, NSAIDs, steroids).
Key Takeaways
- US 6,956,041 is built around a literal enumerated set of JAK3 inhibitor structures plus pharmaceutically acceptable salts; infringement risk is dominated by whether an accused product matches one of the named compounds.
- Claim 2 and claim 5 single out the propionitrile analog as a key narrower target within both composition and method enforcement.
- Claim 3 materially expands practical coverage by requiring only that the composition containing the claimed inhibitor also includes one or more listed additional agents, including major immunosuppressants/biologics and common NSAIDs plus anti-inflammatory steroid.
- Method claim scope (claim 4) is anchored to “inhibition of JAK3” and administration, but still depends on the administered molecule being one of the enumerated structures.
FAQs
1) Does the patent claim “any JAK3 inhibitor” or only specific molecules?
Only specific molecules: claims 1 and 4 use an enumerated “compound selected from” list, and dependent claims narrow to the propionitrile analog.
2) What is the single most important dependent compound in the claim set?
The nitrile analog: “3-{4-Methyl-3-[methyl-(7H-pyrrolo[2,3-d]pyrimidin-4-yl)-amino]-piperidin-1-yl}-3-oxo-propionitrile” (and salts), covered by claims 2 and 5.
3) Can combination therapy be part of infringement even if the co-drug is not a JAK3 inhibitor?
Yes. Claim 3 expands the composition to include additional agents from its listed group, regardless of whether those agents inhibit JAK3.
4) Is the therapeutic indication specified?
No. The method claim states inhibition of JAK3 in a mammal, including humans, without tying to a specific disease indication.
5) What are the highest-probability design-around levers?
The most reliable is to avoid literal identity to every enumerated compound in the list (and corresponding salts). For combination risk, avoid pairing the claimed inhibitor with the specific agents enumerated in claim 3.
References
[1] US Patent 6,956,041 (claims as provided in the prompt).
