Last Updated: November 9, 2026

Details for Patent: 7,674,776

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Summary for Patent: 7,674,776
Title:Combination therapy for effecting weight loss and treating obesity
Abstract:The present invention features a novel therapy for effecting weight loss which involves treating a subject with a sympathomimetic agent (e.g., phentermine or a phentermine-like drug) in combination with an anticonvulsant sulfamate derivative (e.g., topiramate) such that the subject experiences weight loss.The combination methods of the present invention also are effective against symptoms associated with Syndrome X. The invention also features pharmaceutical compositions and kits for use in the practice of these novel therapies.
Inventor(s):Thomas Najarian
Assignee: Vivus LLC
Application Number:US11/385,233
Patent Litigation and PTAB cases: See patent lawsuits and PTAB cases for patent 7,674,776
Patent Claim Types:
see list of patent claims
Use; Composition; Formulation; Dosage form;
Patent landscape, scope, and claims:

Scope and Claim Construction for US Patent 7,674,776 (Phentermine Plus Anticonvulsant Sulfamate Derivatives, Including Topiramate Controlled-Release Weight-Loss Regimens)

US 7,674,776 claims a tightly defined US composition and dosing scheme built around (i) phentermine paired with an anticonvulsant sulfamate derivative defined by a formula (I) sub-structure, and (ii) a set of once-daily weight-loss method claims and controlled-release oral dosage-form architectures that place phentermine in immediate release while the anticonvulsant is delayed and optionally sustained, including embodiments where the anticonvulsant is topiramate and the delayed-release time is specified (4, 8, 12 hours).

Below is a claim-by-claim scope map, then an actionable patent-landscape read across competing IP themes: composition, dosage form architecture, release timing, method of use, and “switching” or design-around risk.

What patents protect the phentermine + anticonvulsant sulfamate weight-loss concept in US 7,674,776?

How claim 1 sets the core infringement fence: “phentermine + anticonvulsant sulfamate derivative” with formula (I)

Claim 1 defines infringement around a composition containing:

  1. phentermine, and
  2. an anticonvulsant agent that is an anticonvulsant sulfamate derivative having structure of formula (I).

Formula (I) limitations (structural gatekeeping):

  • X is CH2 or O
  • R1–R5 are each independently H or C1–C4 alkyl
  • If X is O, then R2 and R3 and/or R4 and R5 can be linked to form:
    • a methylene dioxy linkage —O—CR6R7—O— (R6 and R7 independently H or C1–C3 alkyl), or
    • a cyclopentyl or cyclohexyl ring.

Scope impact:

  • This is not “any anticonvulsant.” The claims require the anticonvulsant to satisfy the sulfamate derivative formula (I). That structure constraint is the main boundary for both breadth and design-around.
  • The X=CH2 vs X=O branching gives two structural “families” inside formula (I), expanding coverage within the sulfamate scaffold while still constraining outside compounds.

Consequence for competitors:

  • Substituting a different anticonvulsant (outside the formula (I) sulfamate derivative space) is a primary design-around lever.
  • Modifying R-group patterning is constrained by the enumerated set (H or C1–C4 alkyl) and, for X=O, by the specific ring/di-dioxy linking possibilities.

How dependent claims layer on release mechanics and timing

The claim set then escalates from structural combination (claim 1) into dosage-form release profiles and timing windows, and then into topiramate-specific embodiments and specific dose strengths.

H3: What are the primary independent claims controlling US infringement risk?

From the text provided, the independent “pillars” are:

  • Claim 1: composition with phentermine + formula (I) sulfamate derivative anticonvulsant.
  • Claim 2–4: composition with release layering (immediate phentermine; controlled anticonvulsant; delayed; sustained).
  • Claim 5–9: once-daily method for desired weight loss, with subject-type variants.
  • Claim 10–17: controlled-release dosage form with phentermine + topiramate (immediate phentermine; delayed topiramate; sustained; and specified delay offsets).
  • Claim 18–22: method for desired weight loss with that controlled-release dosage form, with subject-type variants.
  • Claim 23–32: specific numeric dose embodiments (15/100 and 8/50 mg) and formulation variants (granules/delayed granules; readily dissolvable phentermine).
  • Claim 33–41: layered formulation architecture (topiramate core + phentermine layer with barrier/baffler layers, including enteric polymer / dissolution-retardant coating and hydrophobic coating).
  • Claim 42–46: explicit dosage-form definition with phentermine immediate-release dissolvable form plus delayed-release topiramate granules, including specific dose combinations.
  • Claim 47–56: methods tied to specific dose combinations.
  • Claim 57–59: broader methods using phentermine plus a formula (I) sulfamate anticonvulsant selected to prevent loss of phentermine effectiveness (including side-effect treatment and “Syndrome X”).

These groups operate as multiple claim “attack surfaces” against different generic or reformulation strategies.

How does the formula (I) limitation narrow or expand US 7,674,776?

What exactly does “anticonvulsant sulfamate derivative having structure of formula (I)” cover?

The claim language is structural, not functional. A product must contain:

  • an anticonvulsant that is also a sulfamate derivative,
  • satisfying the formula (I) with the specified X and R-group options,
  • and satisfying the X=O ring/linked group conditions when present.

This is narrower than a functional anticonvulsant selection clause, and it is broader than an explicit list of named drugs.

H3: Key structural “risk” elements for design-around

  • Sulfamate scaffold requirement: eliminating the sulfamate group likely removes the compound from the formula family.
  • X selection (CH2 vs O): shifting the linkage away from these specific options risks non-infringement.
  • R-group envelope: only H or C1–C4 alkyl are permitted for R1–R5, and if X=O, additional constrained linkage motifs are required.

H3: How claims 57–59 broaden beyond “weight loss” to maintain phentermine effectiveness and treat side effects

Claims 57 and 58 recast the formula (I) sulfamate derivative selection as:

  • “selected to prevent the loss of effectiveness of the phentermine,” and
  • methods for treating at least one side effect associated with obesity (claim 58) and “Syndrome X” (claim 59).

This moves from “induce weight loss” to “maintain phentermine efficacy” and manage obesity-associated side effects, expanding potential enforcement if the same composition is used.

When does US 7,674,776 lose exclusivity and what are the practical litigation triggers?

No expiration, filing date, term adjustment, or Patent Term Extension data is provided in the input. Without the underlying bibliographic data for US 7,674,776 (filing date, issue date, PTE/terminal disclaimer status), a definitive “when exclusivity ends” timeline cannot be computed from the claims text alone.

What formulations and dosage-form architectures are protected by US 7,674,776?

Immediate-release phentermine + delayed (and optionally sustained) topiramate is a central architecture

The landscape protection is not just molecular. It is also release engineering:

  • phentermine is immediate release and readily dissolvable in several claims,
  • topiramate (or the formula (I) sulfamate derivative anticonvulsant) is delayed and often controlled-release, and in some claims sustained-release.

H3: What are the specific release timing claims (4h/8h/12h delays)?

Claims 15–17 define a controlled-release dosage form with:

  • immediate-release phentermine,
  • delayed-release topiramate,
  • with topiramate delay relative to phentermine release at 4 hours, 8 hours, or 12 hours.

This creates a quantized infringement zone for products using the same two-drug pairing but different delay offsets.

H3: Dose-strength-specific claims create extra enforcement hooks

Claims 23–24 and 42–46 lock in two numeric combinations:

  • 15 mg phentermine + 100 mg topiramate
  • 8 mg phentermine + 50 mg topiramate

Numeric strength anchoring matters because many generic developers choose fixed-dose strengths first. Even if the general delayed-release concept is approximated, failing the strength-specific combination can avoid these dependent claims, but not necessarily the broader claims.

H3: Granule and matrix claim scope for topiramate delayed release

Claim 25 requires that oral administration:

  • yields immediate release phentermine and controlled release topiramate, and
  • topiramate is present as one or more of:
    • granules,
    • delayed release granules,
    • granules within a matrix,
    • or combination with a polymeric mixture.

Claims 26 and 30 further narrow topiramate to delayed release granules.

H3: “Phentermine readily dissolvable form” is a separate hook

Claims 27–28 and 31–32 specify phentermine is in a readily dissolvable form, linked to the controlled-release topiramate architecture. This gives the patentee a path to argue infringement even if the carrier system differs, as long as phentermine dissolves rapidly at administration.

What multi-layer core-shell-type protections exist (barrier and baffler layers)?

The strongest “formulation IP engineering” appears in claims 33–41, which define a specific multi-layer concept:

H3: Topiramate core + phentermine layer with barrier layer

  • Claim 33: formulation with a topiramate core and a layer of phentermine such that:
    • phentermine is immediate release,
    • topiramate is delayed or sustained release.
  • Claim 35: includes a barrier layer between core surface and phentermine layer that limits drug release from the surface.
  • Claim 36: barrier prevents dissolution of the core upon first exposure to gastric fluid.
  • Claims 37–40: barrier can comprise:
    • a disintegrant, and/or
    • a dissolution-retardant coating,
    • where the dissolution-retardant coating is polymeric and may be an enteric polymer.
  • Claims 41: baffler layer comprises a hydrophobic coating.

Scope impact:

  • These claims are not just “controlled release.” They target specific inter-layer functional behavior (resists gastric dissolution at first exposure) and accept specific materials classes (enteric polymer, hydrophobic coating).
  • Design-around can include changing the architecture so that phentermine is not layered in the claimed manner, or avoiding the defined barrier/baffler behavior.

What are the method-of-use claim scopes and subject-class coverage?

H3: Weight-loss “until desired weight loss is achieved” dosing

Claims 5–9 and 18–22 include:

  • once daily administration,
  • “until the subject has experienced the desired weight loss,”
  • and subject-type qualifiers:
    • overweight (claims 6, 19),
    • obese (claims 7, 20),
    • neither overweight nor obese (claims 8, 21),
    • subject suffers from a condition alleviated with loss of body weight (claims 9, 22).

Scope impact:

  • The method claims are broad on patient selection. They are written to capture a spectrum of BMI/status and indications tied to weight loss outcomes, reducing loopholes based on patient screening.

H3: Dose-strength methods

Claims 47–51 and 52–56 tie the regimen to:

  • 15/100 mg daily and then until weight loss achieved, or
  • 8/50 mg daily and then until weight loss achieved.

H3: Efficacy-maintenance and side-effect/Syndrome X treatment

Claims 57–59:

  • administer phentermine plus a formula (I) sulfamate derivative,
  • the anticonvulsant is selected to “prevent the loss of effectiveness of the phentermine,”
  • includes methods to treat:
    • obesity-associated side effects (claim 58),
    • “Syndrome X” (claim 59).

These claims can be asserted even where weight loss is not the only outcome.

What US patent 7,674,776 claim scope implies for generic entry and design-around?

The highest-risk infringement scenario

A generic or reformulated product that:

  • contains phentermine and topiramate (or a compound meeting formula (I)),
  • provides immediate-release phentermine,
  • provides delayed-release topiramate,
  • uses delay times of 4/8/12 hours and/or uses strengths 15/100 or 8/50 mg,
  • and/or uses a multi-layer core/barrier architecture consistent with claims 33–41, is exposed to the broadest dependent and composition formulation claims.

The most viable “escape” levers (claim-based)

  • Change the anticonvulsant active to something outside the formula (I) sulfamate derivative family (for claims 1–9, 57–59).
  • Change the release pattern such that topiramate is not delayed relative to phentermine (or not delayed by the claimed offsets) (for claims 2–4, 10–17).
  • Change dose strengths away from 15/100 and 8/50 mg fixed combinations (for strength-specific dependent claims), while noting broader claims may still apply.
  • Change layering architecture so it lacks the specified barrier/baffler functional behavior, enteric polymer coating, or hydrophobic baffler layer (for claims 33–41).

Key Takeaways

  • US 7,674,776 is built on a two-part infringement structure: (1) phentermine + a formula (I) anticonvulsant sulfamate derivative and (2) a controlled-release oral dosage architecture that places phentermine in immediate release and the anticonvulsant in delayed and optionally sustained release.
  • The patent contains multiple enforcement hooks: structural chemical limitations (formula I), release timing (4/8/12-hour topiramate delay), dose-strength combinations (15/100 and 8/50 mg), and multi-layer formulation features (core + phentermine layer + barrier/baffler with enteric polymer/hydrophobic coating).
  • Method claims are broad on subject selection and “treat until desired weight loss” language, and claims 57–59 expand enforcement to maintaining phentermine effectiveness and treating obesity-related side effects or “Syndrome X.”
  • A definitive exclusivity timeline cannot be derived from the claims excerpt alone because filing/issue date and any term adjustments are not provided.

FAQs

1) Does US 7,674,776 cover any anticonvulsant used with phentermine for weight loss?
No. Claims 1 and 57–59 require an anticonvulsant that fits the sulfamate derivative formula (I) structure.

2) Are topiramate-specific claims limited to once-daily administration?
The topiramate dosage-form claims are formulation definitions (claims 10–17, 23–46, 33–41), and the corresponding method claims (claims 18, 47–56) specify once daily or daily basis until weight loss achieved.

3) What design-around risk comes from the 4-hour, 8-hour, and 12-hour delay offsets?
If a competing product matches phentermine immediate release plus delayed topiramate with the same delay offsets, it is within the explicit timing claims 15–17.

4) Do the claims require a particular granule technology for topiramate?
They cover several delayed-release constructions: granules, delayed release granules, granules in a matrix, or combinations with polymeric mixtures; delayed release granules are singled out in dependent claims.

5) Can a product avoid infringement by changing the phentermine dose strength?
It can reduce exposure to the strength-specific dependent claims tied to 15/100 and 8/50 mg, but broader controlled-release and pairing claims may still apply.

References

  1. United States Patent 7,674,776 (claims provided in prompt).

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Drugs Protected by US Patent 7,674,776

Applicant Tradename Generic Name Dosage NDA Approval Date TE Type RLD RS Patent No. Patent Expiration Product Substance Delist Req. Patented / Exclusive Use Submissiondate
>Applicant >Tradename >Generic Name >Dosage >NDA >Approval Date >TE >Type >RLD >RS >Patent No. >Patent Expiration >Product >Substance >Delist Req. >Patented / Exclusive Use >Submissiondate

International Family Members for US Patent 7,674,776

Country Patent Number Estimated Expiration Supplementary Protection Certificate SPC Country SPC Expiration
Austria 369126 ⤷  Start Trial
Australia 2008262566 ⤷  Start Trial
Australia 5489600 ⤷  Start Trial
Australia 770068 ⤷  Start Trial
Canada 2377330 ⤷  Start Trial
Canada 2686633 ⤷  Start Trial
Canada 2692042 ⤷  Start Trial
>Country >Patent Number >Estimated Expiration >Supplementary Protection Certificate >SPC Country >SPC Expiration

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