United States Patent 7,011,815: What Is Claimed and How Broad Is the Scope?
What does US 7,011,815 claim in plain scope terms?
US 7,011,815 is a method-of-use patent that claims MR imaging (MRI) in a mammal using a specific paramagnetic contrast agent architecture. The method is defined by two mandatory steps:
- Administer a contrast agent (or a pharmaceutically acceptable salt) that has a defined formula:
IEM-[Lm-{BHEMs-PPBMo}p]q
where the variables m, s, o, p, q are each “one” (per claim language), and where:
- IEM is an image enhancing moiety that is an element of a defined structure group (claim contains a complex sub-structure depiction and defined substitution rules).
- M is a paramagnetic metal ion selected from a list including Gd(III) and multiple other transition lanthanide/metal ions.
- L is a linker of 1 to 4 —CH2— groups.
- BHEM is a phosphodiester moiety.
- PPBM is an HSA binding moiety.
- Subject the mammal to MR imaging, optionally with timing, dosage, and anatomic targeting limitations in dependent claims.
The practical claim strategy is clear: pin MRI utility to a particular “HSA-binding phosphodiester + paramagnetic center + defined linker + defined IEM embedding” platform rather than claiming generic gadolinium-based contrast agents.
What is the scope of the core independent claim (Claim 1)?
What is the mandatory contrast-agent structural boundary?
Claim 1 requires that the administered agent match the formula:
- IEM-[Lm-{BHEMs-PPBMo}p]q, with m, s, o, p, q = 1.
It then further constrains key building blocks:
Paramagnetic center (M):
Selected from: Gd(III), Fe(III), Mn(II), Mn(III), Cr(III), Cu(II), Dy(III), Tb(III), Ho(III), Er(III), Eu(III).
Linker (L):
BHEM:
PPBM:
- An HSA (human serum albumin) binding moiety.
Hydrogen vs substituted position rules (R groups):
The claim includes a group substitution rule: one of R1–R11 is -[Lm-{BHEMs-PPBMo}p], while the remaining R1–R11 are hydrogen.
This means the conjugate positioning is controlled: the platform must be attached in the specific site pattern covered by the claim.
R12–R14 options:
- O− and NH2 (each can be the same or different).
R15 options:
- H, CH2CH(OH)CH3, a hydroxy alkyl, or CH2COR12.
Salts:
Claim 1 allows a pharmaceutically acceptable salt of the contrast agent.
Net effect: even though the formula is written in a generalized way, the claim is not a free-form “any MR contrast agent” claim. It is a platform-specific conjugate claim defined by (1) paramagnetic metal selection, (2) linker length window, (3) phosphodiester identity, (4) HSA binding identity, and (5) defined substitution rules.
What is the mandatory method boundary (MRI context)?
Claim 1 only requires:
- administering the agent to a mammal and
- performing MR imaging.
It does not restrict the body system or indication in the independent claim. It is therefore broad on indication at the independent level, but the dependent claims narrow to vasculature, tumor, and brain use-cases.
How broad is the administration scope: salts, dose, timing, concentration?
What salts are explicitly covered (Claim 2)?
Claim 2 limits “pharmaceutically acceptable salt” to:
- N-methyl-D-glucamine
- calcium
- sodium
If an accused product uses a different salt form, Claim 2 does not apply by its own terms, but Claim 1 still covers “pharmaceutically acceptable salt” generally (unless prosecution history or specification limits scope, which are not provided here).
What dosing/concentration windows are explicitly covered (Claims 6 and 7)?
Claim 6: agent concentration 0.001 to 1 mmol/kg body weight
Claim 7: narrower 0.005 to 0.05 mmol/kg body weight
This creates a clear numeric infringement “sweet spot” for claims constructed around dose-response or administration protocols. Any dosing outside those windows may fall outside dependent coverage, but Claim 1 still contains no numeric dose limit itself. The independent claim therefore remains broad unless enforceability turns on validity or construction not supplied here.
What timing boundary is explicitly covered (Claim 5)?
Claim 5: at least a portion of the imaging occurs 10 minutes or later after administration.
Again, timing is not required in Claim 1, but Claim 5 adds a protocol limitation that can matter for design-arounds (imaging earlier than 10 minutes) and for assessing claim charts based on clinical protocols.
What is the mammal scope?
Is “human” required anywhere?
Claim 3: the mammal is a human.
Claim 1 itself uses “a mammal”, so the independent claim covers all mammals if structural and protocol requirements are met. Claim 3 is a dependent claim narrowing to humans for enforcement targeting clinical use.
What specific agent embodiments are explicitly listed (Claim 8)?
Claim 8: contrast agent selected from:
- MS-315, MS-317, MS-321, MS-322, MS-325, MS-326, MS-327, MS-328
This is significant for a patent landscape because it:
- ties the platform formula to enumerated products, and
- gives a roadmap for assessing competitive infringement where proprietary agents are marketed under those designations.
If a competitor uses a contrast agent marketed under another identifier, infringement analysis depends on whether it meets the platform structural constraints, not merely the label name.
Where does MRI indication narrow inside the claim set?
Vasculature imaging (Claim 4)
Claim 4: imaging includes at least a portion of the vasculature.
This narrows utility to vascular beds and supports enforcement for angiography-type MRI workflows.
Tumor imaging (Claim 9)
Claim 9: imaging includes imaging a tumor.
This narrows method application to oncologic imaging.
Brain imaging and BBB targeting (Claims 10 and 11)
Claim 10: imaging the brain.
Claim 11: imaging the brain’s blood-brain barrier (BBB).
This pairing is tight because BBB-specific imaging often uses agents that exhibit delayed kinetics and targeted transport. The independent claim does not require BBB targeting, but the dependent claims do.
Cognitive event context (Claim 12)
Claim 12: brain imaging occurs when the mammal is undergoing cognitive events.
This is a narrow procedural/experimental context limitation. It also suggests the patent is aimed at functional or event-timed imaging protocols rather than solely anatomical scans.
Patent landscape implications: how competitors likely evaluate risk
1) Design-around vectors for competitors
Based on the claim structure, the main “swing factors” for infringement risk are:
- Metal choice (M): Claim 1 lists multiple metals. Avoidance would require using a metal not in the enumerated set, while still meeting other structural requirements (likely difficult if the platform is meant for albumin binding + phosphodiester).
- Linker length (L): only 1 to 4 —CH2— groups.
- BHEM identity: must be a phosphodiester moiety.
- PPBM identity: must be an HSA binding moiety.
- Conjugation pattern: one of R1–R11 is the appended bracketed moiety; remaining R1–R11 are hydrogen, plus defined substituents at R12–R14 and R15 options.
For a generic “gadolinium albumin binder” product that does not contain the same phosphodiester element or does not meet the linker length/substitution constraints, claim coverage may not attach.
2) Enforcement leverage created by Claim 8 enumeration
If MS-series agents (listed in Claim 8) are sold or used in US clinical trials for MRI, then the claim set gives direct mapping routes:
- an accused product using MS-315/MS-317/MS-321/MS-322/MS-325/MS-326/MS-327/MS-328 is already within the claim’s named embodiment set, assuming structural match.
- MRI protocols that fit Claim 4, Claim 5 (timing), Claim 9–12 (tumor/brain/BBB/cognitive events) strengthen the dependent-claim positioning for infringement arguments.
3) Broad independent claim vs narrow dependent claim set
- Claim 1 is broad on indication (no anatomy required).
- It is narrow on agent structure and metal set and broad on mammal type.
- Dependent claims then narrow the application domain (vasculature, tumor, brain, BBB, cognitive events) and add operational constraints (salt set, dose window, timing).
From a landscape perspective, this pattern is common when a patent aims to capture a class of platform agents but wants enforceable hooks tied to specific clinical use patterns.
Claim-to-competitive product mapping framework (useful for landscape diligence)
Step 1: Check structural compliance with Claim 1 platform constraints
An analyst would screen whether the competitor agent has:
- the IEM-[Lm-{BHEMs-PPBMo}p]q construct with the constraint that m=s=o=p=q=1 (as written),
- the phosphodiester component labeled BHEM,
- an HSA binding component labeled PPBM,
- a linker L in the 1 to 4 methylene range,
- and a paramagnetic metal M that matches the listed set.
Step 2: Check method protocol overlap
Even if structure matches, enforceability strengthens when the competitor’s use includes:
- at least 10 minutes post-administration for the relevant imaging step (Claim 5),
- administration amount within 0.001 to 1 mmol/kg (Claim 6) or 0.005 to 0.05 mmol/kg (Claim 7),
- and relevant anatomy/indication: vasculature (Claim 4), tumor (Claim 9), brain + BBB (Claims 10–11), or cognitive event context (Claim 12).
Step 3: Check naming overlap with Claim 8
If the competitor agent is marketed as one of the MS-xxx compounds listed in Claim 8, it reduces ambiguity in product identification even though structural confirmation still governs infringement.
Key Takeaways
- US 7,011,815 claims an MRI method that depends on administering a highly specific albumin-binding phosphodiester conjugate with a defined paramagnetic metal set, linker length window (1–4 CH2), and strict structural substitution rules.
- Independent Claim 1 is broad on indication (any mammal; imaging generally) but narrow on agent architecture and the permitted paramagnetic metal ions.
- Dependent claims provide enforceable narrowing: human (Claim 3), vasculature (Claim 4), post-dose timing (>=10 minutes) (Claim 5), dose ranges (Claims 6–7), tumor (Claim 9), brain (Claim 10), BBB (Claim 11), and cognitive events (Claim 12).
- The patent lists specific agents (MS-315/MS-317/MS-321/MS-322/MS-325/MS-326/MS-327/MS-328), creating a direct diligence path for product-level landscape decisions.
FAQs
-
Does US 7,011,815 require brain imaging in the independent claim?
No. Claim 1 requires MR imaging generally after administration; brain/BBB restrictions appear only in dependent claims.
-
Which paramagnetic metals are explicitly covered by Claim 1?
Gd(III), Fe(III), Mn(II), Mn(III), Cr(III), Cu(II), Dy(III), Tb(III), Ho(III), Er(III), Eu(III).
-
What linker length is allowed in the contrast agent?
A linker L consisting of 1 to 4 —CH2— groups.
-
What timing window does Claim 5 add?
Imaging occurs 10 minutes or later after administration (at least for the portion being imaged).
-
Are specific doses required for infringement?
Claim 1 itself has no numeric dose requirement, but dependent claims add 0.001 to 1 mmol/kg (Claim 6) and 0.005 to 0.05 mmol/kg (Claim 7).
References
[1] User-provided claim text for US Patent 7,011,815 (Claims 1–12).
