United States Patent 7,951,133: Claim Scope, Expiration, Litigation Risk, and Sinus Implant Patent Landscape

United States Patent No. 7,951,133 covers a method of treating a sinus condition by placing a biodegradable, drug-containing implant into a paranasal sinus. The independent claim requires a two-form implant: a first form that facilitates delivery and a second form that resists clearance after deployment. The claims also cover delivery through a sinus ostium or sinus wall, use of a pusher or pressurized gas, polymeric implants, specific conduit geometries, fracture lines, and four corticosteroids.

The patent is directed to a delivery method rather than merely to a steroid compound, a standalone implant composition, or a particular commercial product. Its commercial relevance is greatest for steroid-eluting sinus implants and delivery systems that deploy an implant which changes shape or configuration after placement.

What does United States Patent 7,951,133 protect?

The patent protects a treatment sequence with four central elements:

A sinus condition is treated.
Access is created to a paranasal sinus cavity.
A delivery device carries a biodegradable implant into that cavity.
The implant changes from a delivery form to a retention form and contains a therapeutic amount of an active agent.

The key limitation is the implant's change in form. Claim 1 does not broadly cover every biodegradable sinus implant. It requires:

a solid implant;
a first delivery form;
a second form different from the first;
a second form that substantially prevents clearance from the sinus cavity; and
a therapeutic amount of an active agent.

A device that remains in the same physical configuration before and after delivery may fall outside the literal scope of claim 1, even if it is biodegradable, drug-eluting, and placed in a sinus.

Claim architecture

Claim	Subject matter	Commercial significance
1	Core treatment method using a two-form biodegradable drug implant	Primary infringement risk
2	Delivery through a sinus ostium	Covers trans-ostial placement
3	Delivery through a sinus wall	Covers wall-access procedures
4	Delivery with a pusher	Covers mechanical deployment
5	Delivery with pressurized gas	Covers pneumatic deployment
6	Biodegradable polymeric implant	Narrows the implant material
7	Sharp-tipped conduit	Covers penetrating delivery tools
8	Angulated conduit	Covers curved or angled tools
9	Distal conduit angle from about 0 to about 135 degrees	Defines the angled-tool range
10	Distal opening at the conduit tip	Covers end-opening catheters
11	Distal opening in the conduit side wall	Covers side-opening catheters
12	Predetermined fracture lines	Covers implants designed to break or expand
13	Anti-inflammatory active agent	Narrows the therapeutic class
14	Mometasone furoate	Covers mometasone-containing implants
15	Budesonide	Covers budesonide-containing implants
16	Fluticasone propionate	Covers fluticasone-containing implants
17	Triamcinolone acetonide	Covers triamcinolone-containing implants

Claims 2 through 17 depend on claim 1. A product or procedure must satisfy every limitation of claim 1 plus the additional limitation in the dependent claim asserted.

How broad is claim 1 of Patent 7,951,133?

Claim 1 is structurally narrow but commercially meaningful. Its breadth comes from the functional retention requirement, while its limitations come from the required delivery-form and post-delivery-form distinction.

Elements likely to control infringement

The most important claim-construction issues are:

"Solid implant"

The claim requires a solid implant. A liquid formulation, gel delivered in a liquid state, or drug solution would not literally satisfy this limitation unless the product is considered a solid implant at the relevant point in the delivery process.

A solid polymer matrix, molded insert, compressed body, or fractured solid structure is more likely to satisfy the limitation.

"First delivery form"

The implant must have a configuration that facilitates delivery into the sinus. This language potentially covers an implant that is compressed, folded, elongated, constrained, or otherwise configured to pass through a conduit or ostium.

The claim does not require a specific first shape. That provides flexibility for design-around analysis, but it also creates a factual issue concerning what form the implant has during loading and placement.

"Second form, different from the first form"

A change in physical configuration is central. The claim does not expressly require expansion, swelling, unfolding, fracture, or deployment into a particular geometry. A court could interpret "different" broadly, subject to the specification and prosecution history.

Potential examples include:

a compressed implant that expands;
a folded implant that unfolds;
an elongated implant that assumes a larger or irregular shape;
an implant that fractures along predetermined lines;
an implant that changes from a constrained delivery geometry to a retention geometry.

"Substantially prevents clearance"

This is a functional limitation. The implant need not be permanently fixed, but its deployed shape must materially reduce migration or removal from the sinus cavity.

The phrase does not require complete prevention of clearance. A product may still biodegrade, fragment, or eventually leave the cavity while satisfying the limitation during its therapeutic residence time.

This language may create both infringement and validity disputes. A challenger could argue that the phrase lacks objective boundaries. The patent holder would likely respond that the specification, examples, implant geometry, and clinical context inform the meaning of substantial retention.

"Therapeutic amount of an active agent"

The implant must contain enough active agent to produce a therapeutic effect. The claim does not set a dose, release rate, concentration, or duration. The active agent can be an anti-inflammatory compound under dependent claim 13 or another therapeutic agent under claim 1.

What formulations are protected by Patent 7,951,133?

The claims cover drug-containing biodegradable implants, particularly polymeric implants and steroid-eluting implants. The patent does not require a specific polymer, excipient, coating, drug loading, degradation period, or release profile.

Protected formulation categories

Potentially covered formulations include:

biodegradable polymer matrices;
solid drug-polymer implants;
implants with compressed or folded delivery geometries;
implants with expansion or unfolding behavior;
implants with predetermined fracture lines;
implants containing mometasone furoate;
implants containing budesonide;
implants containing fluticasone propionate; and
implants containing triamcinolone acetonide.

Claim 6 expressly identifies biodegradable polymeric implants. Claim 12 separately identifies fracture lines. Claims 14 through 17 identify active pharmaceutical ingredients.

The patent does not, based on the supplied claims, require:

mometasone furoate specifically in the independent claim;
a particular polymer such as polylactic acid, polyglycolic acid, or a copolymer;
a specific implant size;
a particular drug-release duration;
a specific sinus;
a specified dose;
a particular FDA-approved product; or
a particular delivery route other than the alternatives added by dependent claims.

A formulation with the same drug but without the claimed two-form behavior may avoid literal infringement. Conversely, changing the polymer or dose may not avoid infringement if the implant otherwise meets the claim elements.

What delivery devices and procedures are covered?

The patent claims both the implant and the method of placing it. The delivery device is not limited to one commercial catheter.

Claim 1 broadly requires a delivery device loaded with the biodegradable implant. Dependent claims identify specific delivery modes and structures:

a pusher;
pressurized gas;
a sharp-tipped conduit;
an angulated conduit;
a conduit angled from about zero degrees to about 135 degrees;
a tip-opening conduit; and
a side-opening conduit.

The claims therefore reach procedures in which the implant is inserted through an existing sinus ostium and procedures in which access is created through a sinus wall. The method may be practiced by a physician, hospital, or manufacturer depending on how direct and divided infringement theories are applied.

Ostium versus sinus-wall delivery

Claim 2 covers delivery through a sinus ostium. This is important for trans-ostial procedures that use a natural or surgically enlarged opening.

Claim 3 covers delivery through a sinus wall. This limitation may apply to procedures in which an access path is created directly through tissue or bone rather than through the ostium.

Claims 2 and 3 are alternatives, not cumulative requirements. A procedure need not use both routes to infringe either dependent claim.

What is the scope of claims 13 through 17 for corticosteroid implants?

Claims 13 through 17 narrow the active agent to anti-inflammatory drugs and then identify four corticosteroids:

Claim	Active agent
13	An anti-inflammatory active agent
14	Mometasone furoate
15	Budesonide
16	Fluticasone propionate
17	Triamcinolone acetonide

A mometasone furoate implant can fall within claim 14 only if it also satisfies every limitation of claims 1 and 13. The presence of mometasone alone is insufficient.

The same applies to claims 15 through 17. A conventional nasal spray, irrigated steroid solution, or nonimplant formulation would generally lack the claimed solid biodegradable implant and two-form retention structure.

When does United States Patent 7,951,133 lose exclusivity?

The patent's expiration date must be determined from the complete USPTO prosecution record, including the earliest effective nonprovisional priority date, patent term adjustment, terminal disclaimers, and any statutory extensions. The claims supplied do not establish those dates.

Patent term is generally governed by 35 U.S.C. § 154 and is ordinarily 20 years from the earliest effective U.S. nonprovisional filing date, subject to statutory adjustments. A patent issued in 2011 may therefore remain relevant well beyond its issue date. Patent expiration is not calculated as 20 years from issuance.

The practical exclusivity analysis should separate:

patent expiration;
FDA regulatory exclusivity;
medical-device approval status;
Orange Book listing status; and
contractual or settlement restrictions.

A patent can expire while a commercial product remains protected by other patents. Conversely, a patent can remain unexpired without creating an automatic barrier to a competing product that does not satisfy the claims.

What is the Orange Book status of Patent 7,951,133?

The supplied record does not establish an Orange Book listing for Patent 7,951,133. Sinus implants are commonly regulated as drug-device combination products or medical devices rather than as conventional NDA drug products.

The Orange Book generally lists patents submitted for approved drug products under the applicable FDA drug-approval framework. A sinus implant approved through a device pathway may not have a conventional Orange Book patent listing. FDA approval of a product therefore does not establish that this patent is listed against the product.

Paragraph IV relevance

A Paragraph IV certification is used in an abbreviated new drug application to challenge patents listed for a reference listed drug. If the relevant sinus implant is not an Orange Book-listed NDA product, a conventional Paragraph IV pathway may not be available for challenging this patent.

A competitor may instead face:

a patent-infringement action under 35 U.S.C. § 271;
a declaratory-judgment action;
an inter partes review petition;
a post-grant or ex parte reexamination strategy; or
a device regulatory pathway independent of the Orange Book.

The regulatory pathway must be analyzed separately from patent infringement.

Which companies and products compete with this patent estate?

The commercial field includes steroid-eluting sinus implants and delivery systems used after endoscopic sinus surgery or for chronic rhinosinusitis. Intersect ENT developed the best-known U.S. sinus implant franchise and was acquired by Medtronic in 2022. Relevant commercial products include the Propel family and Sinuva, subject to the specific indication and regulatory authorization for each product.

Product or platform	Company association	General technology	Patent relevance
Propel family	Intersect ENT, now associated with Medtronic	Steroid-eluting sinus implant	Directly relevant to implant, drug-release, and delivery patents
Propel Mini	Intersect ENT, now associated with Medtronic	Smaller steroid-eluting implant	Potentially relevant to size, deployment, and formulation claims
Propel Contour	Intersect ENT, now associated with Medtronic	Sinus-specific implant geometry	Relevant to anatomy-specific retention and delivery claims
Sinuva	Intersect ENT, now associated with Medtronic	Steroid-eluting implant for recurrent nasal polyps	Relevant to implant, formulation, and method-of-use patent families
Other sinus stents and drug-delivery systems	Multiple device companies	Mechanical support or local drug delivery	May avoid claim 1 if no biodegradable two-form implant is used

The relevant competitive patent estate is broader than Patent 7,951,133. It may include separate patents covering:

implant composition;
polymer selection;
drug loading;
release kinetics;
implant geometry;
sinus-specific shape;
delivery catheter structure;
deployment methods;
manufacturing processes;
treatment of nasal polyps;
treatment after sinus surgery; and
specific combinations of drug and implant.

A freedom-to-operate opinion limited to Patent 7,951,133 would not assess the full estate.

How strong is the patent estate for a commercial sinus implant?

Patent 7,951,133 has meaningful claim coverage if the accused product uses a solid biodegradable implant that changes configuration after delivery and remains in the sinus. Its strongest features are the combination of:

sinus placement;
biodegradable solid structure;
delivery configuration;
retention configuration;
active pharmaceutical ingredient; and
specialized delivery conduit options.

Its principal vulnerabilities are claim construction and prior-art issues surrounding deployable implants, biodegradable drug delivery, sinus stents, and shape-memory or fracture-based retention structures.

Strength assessment

Issue	Assessment
Core concept	Commercially relevant
Claim breadth	Moderate; broad functional language but multiple structural limitations
Design-around potential	Significant if a competitor avoids the two-form limitation
Formulation protection	Limited to the claimed implant context
Steroid coverage	Expressly covers four corticosteroids through dependent claims
Delivery-device coverage	Broad functional claim with several narrower structural claims
Manufacturing protection	Not apparent from the supplied claims
Regulatory exclusivity	Separate from patent protection
Biosimilar relevance	Low; the products are not biologic products
Generic-drug relevance	Limited where products are device-led or combination products

What generic launch risks exist?

A conventional generic nasal corticosteroid is not automatically a substitute for a biodegradable sinus implant. The commercial threat depends on whether the competitor launches:

an ordinary nasal spray or irrigation product;
a nonbiodegradable sinus stent;
a biodegradable implant without a form change;
a drug-eluting implant with a different retention mechanism; or
a substantially similar two-form implant.

The highest infringement risk arises from a product that:

is solid during delivery;
is biodegradable;
contains one of the claimed corticosteroids;
is delivered through a sinus ostium or sinus wall;
expands, unfolds, fractures, or otherwise changes form; and
remains in the sinus because of its deployed configuration.

A product that uses a liquid, gel, nonbiodegradable material, fixed-shape implant, or different retention mechanism may present a lower risk under the supplied claims. That conclusion would not eliminate risk from other patents.

Does biosimilar law affect this patent?

No material biosimilar issue appears from the claims. Mometasone furoate, budesonide, fluticasone propionate, and triamcinolone acetonide are small-molecule corticosteroids, not biologics subject to the Biologics Price Competition and Innovation Act biosimilar pathway.

Competitive products would more likely proceed through:

an NDA or abbreviated pathway for a drug product;
a 510(k), De Novo, or PMA pathway for a device;
a combination-product pathway; or
a product-specific FDA route determined by the primary mode of action.

The regulatory route does not determine infringement, and patent clearance does not establish FDA approval eligibility.

What patent litigation and settlement risks should be assessed?

The supplied claims do not identify a litigation docket, asserted patent set, settlement agreement, or license. Patent 7,951,133 should therefore be analyzed as one asset within a larger portfolio rather than as a complete litigation picture.

For a launch or licensing review, the principal legal questions are:

whether the patent is still enforceable;
whether any terminal disclaimer affects its term;
whether claim 1 survived prosecution without material narrowing;
whether prior art disclosed deployable sinus implants;
whether the accused implant changes from one form to another;
whether the deployed form substantially prevents clearance;
whether the product contains a therapeutic amount of an active agent;
whether the relevant entity has standing to sue;
whether any license or acquisition transferred rights; and
whether related continuation patents remain unexpired.

A settlement involving another patent in the same product portfolio would not automatically release liability under Patent 7,951,133. Patent-specific release language and affiliated-entity definitions control.

What geographic coverage does Patent 7,951,133 provide?

The patent provides rights in the United States only. It does not directly block manufacture, sale, or use in Europe, Canada, Japan, China, or other jurisdictions.

International protection must be assessed through related national applications and granted patents. The commercial analysis should review:

PCT filings;
European Patent Office family members;
Canadian and Australian counterparts;
Japanese and Chinese counterparts;
national-phase status;
local expiration dates;
maintenance-fee status; and
claim differences between jurisdictions.

A U.S. patent may have no enforceable counterpart in a target market, or a foreign counterpart may have materially narrower claims.

Key Takeaways

Patent 7,951,133 covers a method of delivering a biodegradable drug implant into a paranasal sinus.
Claim 1 requires a solid implant with a first delivery form and a different second form that substantially prevents clearance.
The patent does not cover every steroid sinus implant.
Claims 2 through 12 address access routes, deployment methods, conduit geometry, and fracture lines.
Claims 13 through 17 expressly identify anti-inflammatory agents and four corticosteroids.
The strongest infringement scenario involves a biodegradable, solid, drug-containing implant that expands, unfolds, fractures, or otherwise changes shape after sinus delivery.
A liquid, nonbiodegradable, fixed-shape, or nonretaining product may avoid the literal scope of the supplied claims, subject to other patents and the doctrine of equivalents.
Orange Book and Paragraph IV analysis may be limited because sinus implants often proceed through device or combination-product pathways rather than conventional NDA listing.
Biosimilar law has little relevance because the claimed active agents are small-molecule corticosteroids.
Patent expiration cannot be established from the claims alone. The complete USPTO record is required to determine the controlling priority date, patent term adjustment, terminal disclaimers, and enforceability period.
Patent 7,951,133 should be reviewed with related implant-composition, drug-release, delivery-device, method-of-use, manufacturing, and continuation patents.

FAQs About United States Patent 7,951,133

Can a sinus implant avoid Patent 7,951,133 by using a different steroid?

Potentially. Claims 1 through 12 do not require a corticosteroid. Changing the active agent may avoid claims 13 through 17 but would not avoid claim 1 if the implant otherwise satisfies the core structural and functional limitations.

Does biodegradable material alone create infringement risk?

No. Biodegradability is only one limitation. The implant must also be solid, contain a therapeutic amount of active agent, have two different forms, and use the second form to substantially prevent clearance.

Does a fixed-shape implant fall within claim 1?

A fixed-shape implant is less likely to satisfy the express requirement for a first delivery form and a different second form. The analysis depends on whether the implant changes configuration during delivery or deployment.

Can a manufacturer be liable if a physician performs the claimed method?

Potentially. Liability may arise under direct, induced, or contributory infringement theories, depending on the product's instructions, the parties' conduct, and proof that the claimed method is practiced in the United States.

Is a patent license enough to remove FDA launch barriers?

No. A patent license addresses patent rights. FDA approval, device authorization, combination-product classification, manufacturing controls, labeling, and other regulatory requirements remain separate issues.

References

United States Patent and Trademark Office. (2011). U.S. Patent No. 7,951,133, claims 1-17. U.S. Department of Commerce.
United States Code. (2023). 35 U.S.C. § 154: Contents and term of patent; provisional rights.
United States Code. (2023). 35 U.S.C. § 271: Infringement of patent.
U.S. Food and Drug Administration. (2023). Approved drug products with therapeutic equivalence evaluations. Center for Drug Evaluation and Research.
U.S. Food and Drug Administration. (2023). Combination products. U.S. Department of Health and Human Services.
U.S. Food and Drug Administration. (2023). Premarket approval database. U.S. Department of Health and Human Services.

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Australia	2004222340	⤷ Start Trial
Canada	2518960	⤷ Start Trial
European Patent Office	1605863	⤷ Start Trial
European Patent Office	3103422	⤷ Start Trial
Japan	2006520786	⤷ Start Trial
World Intellectual Property Organization (WIPO)	2004082525	⤷ Start Trial
>Country	>Patent Number	>Estimated Expiration	>Supplementary Protection Certificate	>SPC Country	>SPC Expiration

Details for Patent: 7,951,133

Summary for Patent: 7,951,133