Patent: 4,866,035

Summary for Patent: 4,866,035

Title:	Dipeptidyl saccharides as host resistance enhancers in AIDS-immuno-compromised hosts and methods of use
Abstract:	Disclosed are specific dipeptidyl saccharide derivatives which alone, or in combination with an anti-AIDS drug, e.g. azidothymidine, provide protection against opportunistic infection in human individuals whose resistance to infection has been specifically suppressed by an AIDS-related (HIV) virus, as well as help to suppress the AIDS-related infection itself.
Inventor(s):	Durette; Philippe L. (New Providence, NJ)
Assignee:	Merck & Co., Inc. (Rahway, NJ)
Application Number:	07/105,056
Patent Claims:	see list of patent claims

United States Patent 4,866,035: Claim Construction, Scope Limits, and US Patent Landscape Risk

US Patent 4,866,035 claims (i) a combination composition of an aminoglycose-derived compound (a tightly defined glycosylated, substituted aminoglycoside-like scaffold) plus (ii) a named anti-viral/anti-AIDS drug, administered for enhancing host resistance against opportunistic infection in an HIV/AIDS-immunocompromised host, and (iii) a method of use via administration of that composition. The core risk for patent defensibility is that claim 1 reads like a broad genus of aminoglycose derivatives constrained only by a dense set of substituent variables, then is narrowed by the requirement to include one of several older antivirals.

What does claim 1 actually claim (and what does it exclude)?

Claim 1 element map (composition claim)

Claim 1 is a composition for an HIV/AIDS-immunocompromised human host comprising:

1. A compound represented by the structural placeholder “##STR9##,” with multiple substituent variables that define a specific chemical genus.
2. A key explicit exclusion: “provided said glycose is not 2-amino-2-deoxy-D-glucose”.
3. Specific constraints on substituent variables R1 through R9, stereochemical constraints tied to certain substituent configurations.
4. A second active: an anti-viral, anti-AIDS drug selected from:
   • azidothymidine
   • ansamycin
   • ribavirin
   • deoxyytidine (as written)
   • HPA-23
   • AL-721
   • foscarnet
5. The compound plus the named antiviral is formulated in a physiologically acceptable medium and administered in an amount effective to impart resistance against opportunistic infection (bacterial, fungal, or viral).

The “compound” is a genus with steep internal boundaries

The claim does not define a single molecule. It defines a set of substitutable scaffolds using:

• R1: hydrogen; or C1-C7 alkyl (with optional substitutions); or phenyl/benzyl variants with substitution rules; or amino/trifluoromethyl/ether/ester/carboxy-carboxy-ester variants.
• R2: C1-C7 alkyl with optional substitutions; or phenyl variants with substitution rules; or substituted carboxyl functionality (carboxyl, esters, amides).
• R3: H or alkyl C1-C10.
• R4 and R5: both hydrogen; or extensive acyl/benzoyl/naphthoyl/sulfonic acid/carbamoyl variants with optional substituents.
• R6/R7: a linkage rule that allows either:
  • R6 = H or
  • R6 and R7 together form --CH2--CH2--CH2--.
• R7: H; or alkyl C1-C7; hydroxymethyl/mercaptomethyl/benzyl; or substituted benzyl with substitutions matching R1 rules.
• R8/R9: both carboxyl derivatives (carboxyl, esters C1-C7, amides, mono-/di-C1-C3 alkyl amides).

This is chemically “broad,” but it is not free-form. The claim forces:

• a particular glycosylated scaffold (via ##STR9##) plus
• specific substitution logic across multiple positions, and
• stereochemical exclusions/inclusions.

Explicit exclusion that matters for prior art

The claim excludes cases where the glycose identity equals “2-amino-2-deoxy-D-glucose.” That exclusion can defeat art that uses that specific glycone.

Stereochemistry creates both narrowing and interpretive complexity

Claim 1 includes:

• When R3 is lower alkyl, stereochemistry at asymmetric center I can be either D or L, but if the aminoglycose has the 2-amino-2-deoxy-D-glucose configuration, then center I cannot be D.
• When R7 is not H, center II is L or D.
• Center III is fixed to D.

This creates a split between:

• derivative sets where stereochemistry can vary and
• a specific configuration-linked restriction that is likely to map to or exclude certain prior art aminoglycoses.

The composition is anchored by the named antiviral list

Even if the aminoglycose genus is wide, infringement still requires the anti-viral component be one of the enumerated actives (or pharmaceutically acceptable salt forms are addressed for the aminoglycose portion). This is a practical narrowing for enforceability, because competitors can potentially avoid literal infringement by selecting a different antiviral active not in the list.

How broad is the scope in practice (chemical vs clinical breadth)?

Chemical breadth: wide genus, but high structural gating

Claim 1 uses variable substitution. That expands coverage, but the gating includes:

• the aminoglycose scaffold identity implied by “##STR9##,”
• multiple R-position rules,
• carboxyl derivative requirements at R8/R9, and
• the explicit glycone exclusion.

In typical claim construction, variable-substitution claims often get treated as a genus, but novelty and obviousness are tested against known subgenera. The risk is that old aminoglycoses and modified aminoglycoses were already known with similar substitution patterns, and the claim’s stereochemistry exceptions may be insufficient to preserve novelty across the whole genus.

Clinical breadth: opportunistic infection in AIDS/HIV-immunocompromised host

The therapeutic purpose is framed as:

• “enhancing host resistance against opportunistic bacterial, fungal or viral infection.”

This phrasing tends to align with:

• immunomodulation,
• innate immunity enhancement,
• or infection risk reduction.

The key issue for patentability is that the therapeutic effect is often argued broadly, even if specific datasets are limited. If prior art already suggested that aminoglycoside-like molecules can modulate infection susceptibility in immunocompromised contexts, the novelty of the combined approach can collapse under obviousness.

Combination breadth: depends on the enumerated antiviral list

The presence of a named list is critical. The scope is limited to combinations that include at least one antiviral selected from:

• azidothymidine
• ribavirin
• foscarnet
• “ansamycin,” “deoxyytidine,” “HPA-23,” “AL-721”

This “named-drug anchor” can:

• help defensibility against generic “aminoglycose + antiviral” claims, and
• limit enforceability if competitors use different antivirals (or new standard-of-care).

What claim 2 and claim 3 add (narrowing or different subgenera)?

Claim 2

Claim 2 further specifies substitution patterns:

• R1-R2 alkyl group substitution by hydroxy/mercapto and hydroxy/mercapto alkyl-substituted by C1-C3 groups.
• R1 phenyl/benzyl optionally substituted by alkyl C1-C3, hydroxy/mercapto, amino, trifluoromethyl, alkyl dioxy (C1-C4), cycloalkyl dioxy (C5-C7), etherified or esterified hydroxy/mercapto by C1-C3 alkyl or C1-C4 acids.

This is narrower and likely corresponds to specific known derivative classes.

Claim 3

Claim 3 is an explicit reduction to smaller ranges:

• R1 limited to H, C1-C3 alkyl, benzyl, phenyl, or p-substituted phenyl with alkyl, amino, halogen, hydroxy, trifluoromethyl.
• R2 limited to C1-C3 alkyl or phenyl/p-substituted phenyl analogs with similar substituents.
• R3 limited to H or C1-C3 alkyl.
• R4/R5 limited to H or acyl C2-C21 or benzoyl/naphthoyl.
• R7 limited to H, C1-C4 alkyl, hydroxymethyl, mercaptomethyl, benzyl, with an additional rule for R6/R7 forming --CH2 CH2 CH2--.
• R8/R9 limited to carboxyl or limited ester/amides up to C1-C4 alcohol esters and C1-C3 alkyl amides.

This reduces chemical uncertainty for infringement and tends to strengthen validity against overbroad genus challenges, at the cost of commercial coverage.

What does claim 4 add (method claim mechanics)?

Claim 4 is a method:

• “administering to said host a composition comprising a compound according to claim 1.”

It inherits the combination requirement (aminoglycose derivative + enumerated antiviral list). Method claims generally track the composition claims closely and often provide:

• a second enforcement path against use, and
• a patentability hook if clinical effect evidence differs from what is shown in the composition art.

In practice, method claims are vulnerable if:

• the clinical effect is already known or suggested, and
• the administration is obvious from known combinations.

Where does the patent landscape typically pressure this claim set? (critical analysis of obviousness risk)

The landscape pressure: aminoglycoside derivatives are well-trodden

Aminoglycoside chemistry is extensively disclosed across:

• scaffold modifications,
• substitution patterns (alkyl, sulfonates, acylations, carbamoylations),
• esterification and amidation,
• stereochemical variants.

If the ##STR9## scaffold and its substituent permutations map to known families (including non-2-amino-2-deoxy-D-glucose glycones), the claim’s novelty is pressured. The exclusion of one glycone identity helps only if the closest prior art uses that exact glycone.

The combination pressure: older antivirals were independently known

The list includes antivirals that entered HIV treatment decades earlier (and related antivirals for viral infections):

• azidothymidine and foscarnet are classic examples.
• ribavirin is also broadly established across viral contexts.
• “ansamycin” and certain nonstandard names may correspond to older experimental or less common agents.

If prior art teaches:

• enhancing host defenses in immunocompromised patients,
• or using one of these antivirals to control viral burden while supportive agents enhance resistance to opportunistic infection, then combining an aminoglycose-derived immunoresistance agent with a known antiviral can become an obvious “adjunct strategy,” even if the specific pairing is not explicitly disclosed.

“Impart resistance” language can be attacked as functional

Claim 1 defines efficacy by functional result:

• “in an amount effective to impart resistance.”

This can be attacked by showing that the aminoglycose derivative:

• is already known to affect microbial susceptibility or immune responses, and
• the antiviral reduces viral immunosuppression.

Even if the prior art does not mention “opportunistic infections” explicitly, patent examiners and courts often treat functional therapeutic language as a predictable result if the biological rationale is known.

The enumerated drug list is a double-edged sword

Pros:

• narrows infringement to specific antiviral actives.

Cons:

• reduces commercial defensibility against competitors who shift to nonlisted antivirals (which, over time, includes modern ART regimens not on the list).

From a business perspective, the enforcement value depends heavily on whether the relevant market continues to use drugs matching the list, and whether formulations can be designed around the list.

How to evaluate claim vulnerability against competitors’ “design-around” strategies

Design-around lever 1: choose a non-listed antiviral

Because claim 1 requires “anti-viral, anti-AIDS drug selected from” the listed group, a competitor can attempt:

• replacing the antiviral with a different class or agent not listed.

If successful, this can defeat literal infringement and narrow the ability to argue equivalents depending on jurisdiction and prosecution history (not provided here).

Design-around lever 2: modify the aminoglycose glycone or substituent pattern to avoid the exclusion

The explicit exclusion:

• “glycose is not 2-amino-2-deoxy-D-glucose”

can be used as a lever if the competitor uses a derivative in which the glycone equals the excluded identity.

Design-around lever 3: stereochemistry outside the permitted configurations

Claim 1’s stereochemical conditions can be used to avoid coverage if a competitor synthesizes derivatives with:

• center I configuration conflicts tied to the glycone identity and/or R3 relationship,
• center II or center III outside permitted constraints (center III fixed to D is a key limiter).

Design-around lever 4: formulation medium or dosing form

The claim requires “physiologically acceptable medium” and “amount effective.” Competitors may still have trouble avoiding that, but they can potentially:

• avoid “composition” structure by using separate administrations (if the claim requires a combined composition, not a treatment regimen; exact claim construction depends on the “composition” interpretation).

Claim 4 is method-based and may capture separate administration depending on how courts interpret “administering a composition comprising.” That again depends on prosecution record not provided.

Patent landscape assessment: what the provided information supports and what it doesn’t

The user-provided data includes only the claims’ text. It does not include:

• the patent’s filing date, priority date, or issuance date,
• examiner history,
• dependent-claim full text for other claims (beyond 1-4),
• specification examples tying to specific chemical embodiments,
• or the full list of disclosed aminoglycose compounds and experimental results.

Therefore, this analysis can only judge landscape risk at the level of claim structure and typical prior art pressure points for this claim type: aminoglycoside substitution disclosure and combination therapy obviousness.

No further landscape mapping (family members, cited references, prosecution outcomes, litigation status, or “close patents”) can be derived from the provided input.

Key Takeaways

• US 4,866,035 is a combination composition claim: a specific aminoglycoside-like compound genus plus a named antiviral list to treat/improve outcomes in AIDS-related immunocompromised hosts with opportunistic infections.
• The aminoglycose portion is broad by substitution variables (R1-R9) but narrowed by:
  • exclusion of 2-amino-2-deoxy-D-glucose glycone identity,
  • multiple stereochemical constraints,
  • and specific carboxyl derivative requirements at R8/R9.
• Enforceability risk is high on obviousness: aminoglycoside derivatives and older antivirals were individually known; the claim’s functional efficacy (“impart resistance”) can be characterized as a predictable result of known mechanisms.
• The named antiviral list provides a concrete design-around lever: switching to nonlisted antivirals can defeat literal infringement; stereochemistry and glycone identity can also be used to avoid the aminoglycoside subgenera.

FAQs

1. Does claim 1 require both actives in the same formulation?
   Claim 1 requires a “composition comprising” both the aminoglycose-derived compound and an antiviral selected from the enumerated group in a physiologically acceptable medium.

2. What is the most explicit chemical exclusion in claim 1?
   It excludes cases where the glycone is 2-amino-2-deoxy-D-glucose.

3. Is the therapeutic target limited to specific opportunistic infections?
   No. It covers opportunistic bacterial, fungal, or viral infections in a human host immunocompromised by an AIDS-related virus.

4. What is the main enforceability pressure point for claim 1?
   Obviousness risk from prior art that discloses aminoglycoside derivatives and separate antiviral/host-resistance rationales, combined with broad functional efficacy language.

5. How can a competitor potentially design around claim 1?
   Use a nonlisted antiviral (not among the enumerated drugs), use aminoglycose derivatives that avoid the glycone exclusion and stereochemical limits, or structure the regimen to avoid the claimed “composition” concept.

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References

[1] United States Patent 4,866,035, claim text provided in prompt.

Details for Patent 4,866,035

Applicant	Tradename	Biologic Ingredient	Dosage Form	BLA	Approval Date	Patent No.	Expiredate
Hoffmann-la Roche Inc.	PEGASYS COPEGUS COMBINATION PACK	peginterferon alfa-2a and ribavirin		125083	June 04, 2004		2007-10-05
Schering Corporation A Subsidiary Of Merck & Co., Inc.	PEGINTRON/ REBETOL COMBO PACK	peginterferon alfa-2b and ribavirin		125196	June 13, 2008		2007-10-05