United States Patent 6,617,317: Scope, Claims, and US Patent Landscape
US Patent 6,617,317 is a small-molecule composition patent that claims parenteral injectable formulations (saline or aqueous carrier) containing boronic acid compounds defined by a broad Markush-style structural formula (1a). Claim breadth is driven by (i) a large permissive substituent set for ring systems in the variable groups, (ii) allowance of salts, and (iii) multiple downstream dependent claims that narrow to specific classes and named exemplars. The resulting infringement surface in the US is strongest for intravenous/intramuscular/subcutaneous preparations of the formula (1a) boronic acids, and weaker for products that (a) use different active structures or (b) are not formulated for those routes.
What is the claimed invention, in scope terms?
Is the patent limited to a drug product or a compound class?
It claims both, but the core is a composition whose active ingredient is a compound of formula (1a) (or salts). The claimed compositions are for parenteral administration (IV/IM/SC) with a physiologically acceptable carrier (saline or aqueous).
Key structural constraints in the independent claim language you provided:
- Active ingredient: compound of formula (1a) or pharmaceutically acceptable salt
- Carrier: physiologically acceptable saline (or “aqueous carrier” in some claims)
- Routes: intravenous, intramuscular, subcutaneous (sometimes written “sub-cutaneous”)
- Core heteroaromatic scaffold:
- P is either R7—C(O)— or R7—SO2—
- X2 is —C(O)-NH—
- Z1 and Z2 are both hydroxy
- A is zero
- R7 is a defined heteroaryl:
- In claim 1: R7 = pyrazinyl
- In claim 13 and related: R7 expands to quinolinyl, pyrazinyl, pyridyl, quinoxalinyl, furyl, pyrrolyl, N-morpholinyl
- R is hydrogen or alkyl
- R2 and R3: independently hydrogen/alkyl/cycloalkyl/aryl/heteroaryl/—CH2—R5 (depending on claim)
- R5: aryl/aralkyl/alkaryl/cycloalkyl or —W—R6 (W is chalcogen; R6 is alkyl)
- Rings may be optionally substituted (very broad list of substituents: alkyl, cycloalkyl, alkenyl/alkynyl, cyano, amino/amines, benzylamino, nitro, carboxy, carboalkoxy, CF3, halogen, alkoxy, aryl and aryl-substituted alkyl/alkoxy, hydroxy, alkylthio, sulfinyl/sulfonyl, arylthio/sulfinyl/sulfonyl, haloaryls)
What does the formula language practically cover?
In practice, the patent covers:
- A family of boronic acid containing compounds (explicitly stated in claim 12 as “L-phenylalanine-L-leucine boronic acid” derivatives, and embedded in formula (1a) claims)
- With protected or substituted amino-acid side chain motifs (phenylalanine/leucine motif is explicit in claim 12; in formula claims this is represented via X2 and the P substituent pattern)
- With broad heteroaryl “cap” groups attached through carbonyl or sulfonyl linkages (P = R7—C(O)— or R7—SO2—)
- With wide latitude on hydrophobic and aromatic substituents through R2/R3/R5/ R6
Claim-by-claim scope mapping (US 6,617,317 as provided)
Independent composition claim 1: How broad is it?
Claim 1 is the primary independent claim in your excerpt. It claims:
- Composition for IV/IM/SC administration
- Contains a compound of formula (1a) or salt
- P is constrained to R7 = pyrazinyl
- X2 is —C(O)-NH—
- Z1 and Z2 are both hydroxy
- A is zero
- R7 fixed to pyrazinyl at this level
It then broadly defines:
- R: hydrogen or alkyl
- R2 and R3: independently hydrogen, alkyl, cycloalkyl, aryl, or —CH2—R3 (as written in claim 1 text)
- R5: broad aromatic/cycloalkyl options or —W—R6
- Optional substitutions on rings: large Markush list
This is a medium-to-wide scope at the “active ingredient structure” level, but narrowed relative to claim 13-type language because R7 is fixed to pyrazinyl.
Dependent claims 2–11: Where is the narrowing?
Claims 2–11 narrow subsets of variables and give specific embodiments.
- Claim 2 narrows: R is hydrogen or C1–8 alkyl; R3 is C1–6 alkyl
- Claim 3: R3 is C4 alkyl
- Claim 4 repeats claim 1 narrowing for R (hydrogen or C1–8 alkyl)
- Claim 5 narrows R2/R3 to either hydrogen/alkyl/cycloalkyl/aryl or —CH2—R5; R5 limited to aryl/aralkyl/alkaryl/cycloalkyl/alkoxy/alkylthio with an optional substitution menu
- Claims 6–9 focus on chain-length and specific branching:
- Claim 6: R3 is C1–12 alkyl
- Claim 7: R3 is C1–6 alkyl
- Claim 8: R3 is C4 alkyl
- Claim 9: R3 is isobutyl
- Claim 10 introduces a named set for R2:
- R2 is one of isobutyl, 1-naphthylmethyl, 2-naphthylmethyl, benzyl, 4-fluorobenzyl, 4-hydroxybenzyl, 4-(benzyloxy)benzyl, benzylnaphthylmethyl, phenethyl
- Claim 11 combines: R3 = isobutyl; R2 in the same named set
Net effect: these dependents do not shrink to a single compound; they define multiple concrete R2/R3 combinations while leaving the optional ring substitution set open in the general structure language.
Claim 12: Specific exemplar with an explicit named boronic acid
Claim 12 is a composition claim that is no longer formula-driven. It claims a solution containing:
- N-(2-pyrazine)carbonyl-L-phenylalanine-L-leucine boronic acid
and uses an aqueous carrier for IV/IM/SC administration.
This is a direct target claim for at least one specific member of the larger formula family.
Independent claim 13: Broadens the heteroaryl cap group set
Claim 13 is another independent composition claim. It expands the P group options:
- P is R7—C(O)— or R7—SO2—
- R7 can be: quinolinyl, pyrazinyl, pyridyl, quinoxalinyl, furyl, pyrrolyl, or N-morpholinyl
- X2 remains —C(O)—NH—
- Z1 and Z2 are both hydroxy, A is zero
- R remains hydrogen or alkyl
- R2 and R3 are independently chosen from hydrogen/alkyl/cycloalkyl/aryl/heterocycle/—CH2—R5, with R5 broad and substitutable as in claim 1
- Administration language is IV/IM/SC with saline
Compared to claim 1, claim 13 is broader because it replaces R7 fixed = pyrazinyl with a multi-heteroaryl Markush set.
Claim 14: Another named subset of specific boronic acids
Claim 14 lists multiple specific compounds, including:
- N-(2-pyrazine)carbonyl-L-phenylalanine-L-leucine boronic acid
- N-(2-quinoline)sulfonyl-L-homophenylalanine-L-leucine boronic acid
- N-(3-pyridine)carbonyl-L-phenylalanine-L-leucine boronic acid
- N-(4-morpholine)carbonyl-L-phenylalanine-L-leucine boronic acid
- N-(4-morpholine)carbonyl-β-(1-naphthyl)-L-alanine-leucine boronic acid
- N-(8-quinoline)sulfonyl-β-(1-naphthyl)-L-alanine-L-leucine boronic acid
- N-(4-morpholine)carbonyl-(O-benzyl)-L-tyrosine-L-leucine boronic acid
- N-(4-morpholine)carbonyl-L-tyrosine-L-leucine boronic acid
- N-(4-morpholine)carbonyl-[O-(2-pyridylmethyl)]-L-tyrosine-L-leucine boronic acid
This claim is best read as a concrete “hit list” inside a wider formula framework.
Claims 15–20: Structural narrowing via R2/R3 classes and specific functional ranges
- Claim 15: R2 and R3 independently alkyl or —CH2R5; R5 as defined in claim 13
- Claim 16: R2 and R3 independently C1–4 alkyl or —CH2R5; R5 is cycloalkyl/aryl/heterocycle
- Claim 17: R3 = isobutyl; R2 = —CH2R5 where R5 is C5–10 aryl with ring heteroatom substitutions allowed (O/N/S replacing ring carbons)
- Claim 19: R = hydrogen or C1–8 alkyl; R2 and R3 each independently hydrogen, C1–8 alkyl, C3–10 cycloalkyl, C6–10 aryl, C6–10 ar(C1–6)alkyl, pyridylmethyl, or quinolinylmethyl
- Claim 20: compound selected from a named set:
- N-(2-pyridine)carbonyl-L-phenylalanine-L-leucine boronic acid
- N-(2-quinoline)carbonyl-L-phenylalanine-L-leucine boronic acid
- N-(3-furoyl)-L-phenylalanine-L-leucine boronic acid
- N-(2-pyrrolyl)carbonyl-L-phenylalanine-L-leucine boronic acid
- N-(8-quinoline)sulfonyl-L-phenylalanine-L-leucine boronic acid
These are “narrow but real” claim hooks that can support infringement for specific candidates even if generic “formula (1a)” arguments are contested.
Claim 21–22: Another independent composition with more explicit “P = H or protecting moiety”
Claim 21 is an independent claim with formula (1a) active ingredient and saline carrier for IV/IM/SC. It states:
- P is H or an amino-group-protecting moiety
- X2 remains —C(O)-NH—
- R is hydrogen or alkyl
- R2 is naphthylmethyl/pyridylmethyl/quinolylmethyl
- R3 is selected from hydrogen, alkyl, cycloalkyl, aryl, heterocycle, or —CH2—R5 where R5 is aryl/aralkyl/alkaryl/cycloalkyl or —W—R6 (chalcogen)
- Z1 and Z2 hydroxy; A is zero
Claim 22 then nails R3 to isobutyl.
This claim is structurally targeted versus claim 13 because it:
- Narrows R2 to specific methylated heteroaromatic/naphthylmethyl groups
- Broadens P conceptually to include H or amino-protecting moiety, which can widen coverage if P is interpreted broadly to include carbonyl/sulfonyl analogs in the family.
Where infringement pressure concentrates
Route-of-administration constraint
All provided independent claims are composition claims with parenteral administration:
- IV, IM, and SC are explicitly required.
A product that uses a different route is less likely to fall within these composition claims as written.
Active ingredient structural constraint
The dominant determinant is whether the candidate drug is:
- A boronic acid compound within the formula (1a) scaffold, and
- Has substitution patterns that satisfy the claim Markush variables (P, R7, X2, Z1/Z2 hydroxy, A=0, R2/R3/R5 selections).
Named compound claim hooks
Claims 12, 14, and 20 provide direct coverage for specific exemplars. If a later competitor uses any of those specific boronic acids (in the claimed formulation context), the patent provides a clean path to literal infringement arguments.
US patent landscape: how to read competitive risk around this patent
Based on the claim set alone, the US landscape risk for competitors is structured in three layers:
- Composition-level coverage for the formula family
- Claims 1, 13, and 21 cover broad formula (1a) members.
- Composition-level coverage for specific exemplars
- Claims 12, 14, and 20 list named compounds, lowering interpretive burden.
- Dependent claim funneling to specific substituent patterns
- Claims 2–11 and 15–22 lock in narrower subsets such as R3 = isobutyl and specific R2 banks (benzyl/naphthylmethyl/phenethyl series, etc.).
Practical “design-around” implications (claim-reading level)
A competitor can reduce risk only by moving outside the claim construction essentials:
- Change the active scaffold so it no longer matches formula (1a) requirements (especially the hydroxy pair Z1/Z2 and A=0 structure elements, plus X2 = —C(O)-NH— as written in the independent claims).
- Use a different route or formulation that is not “suitable for” IV/IM/SC in the claim sense.
- Avoid the named exemplars if the exact compound is used.
Key Takeaways
- US 6,617,317 is a parenteral composition patent built around boronic acid compounds defined by formula (1a).
- Claim 1 fixes R7 = pyrazinyl; claim 13 expands R7 across multiple heteroaryls; claim 21 restricts R2 to naphthylmethyl/pyridylmethyl/quinolylmethyl while allowing P = H or amino-protecting moiety.
- Claims 12, 14, and 20 list named active ingredients, creating high-confidence coverage for those specific molecules in IV/IM/SC carrier solutions.
- The patent’s commercial risk zone is products whose active ingredient fits the formula (1a) Markush set and whose presentation is a parenteral IV/IM/SC solution.
FAQs
Which variables most determine whether a product falls in-scope?
P (and its R7 definition), X2, Z1/Z2 hydroxy, A=0, and the substituent choices for R2, R3, and R5 within the listed Markush options.
Do the claims cover only one compound or multiple?
Multiple. Independent formula claims cover a family, while dependent claims and separate composition claims list specific named boronic acids.
Is the carrier important for infringement?
Yes. The claims tie coverage to a physiologically acceptable saline carrier (and in one claim to an aqueous carrier) with a solution suitable for IV/IM/SC administration.
Does the patent require IV administration specifically?
The independent composition claims require suitability for intravenous, intramuscular, or subcutaneous administration, so IV use aligns with claim language.
What is the strongest “attack surface” in the claim set?
The named compound provisions in claims 12, 14, and 20, because they map directly to specific active ingredients within the broader formula universe.
References
[1] United States Patent 6,617,317 (claims as provided in prompt).
