Details for Patent: 7,943,582

Which drugs does patent 7,943,582 protect, and when does it expire?

Patent 7,943,582 protects INVOKAMET XR, INVOKAMET, and INVOKANA, and is included in three NDAs.

Protection for INVOKAMET XR has been extended six months for pediatric studies, as indicated by the *PED designation in the table below.

This patent has fifty patent family members in thirty-eight countries.

Summary for Patent: 7,943,582

Title:	Crystalline form of 1-(β-D-glucopyransoyl)-4-methyl-3-[5-(4-fluorophenyl)-2- thienylmethyl]benzene hemihydrate
Abstract:	A novel crystal form of 1-(β-D-glucopyranosyl)-4-methyl-3-[5-(4-fluorophenyl)-2-thienylmethyl]benzene hemihydrate, and having favorable characteristics, is characterized by its x-ray powder diffraction pattern and/or by its infra-red spectrum.
Inventor(s):	Sumihiro Nomura, Eiji Kawanishi
Assignee:	Tanabe Pharma Corp
Application Number:	US11/987,670
Patent Litigation and PTAB cases:	See patent lawsuits and PTAB cases for patent 7,943,582
Patent Claim Types: see list of patent claims	Use; Composition; Process;

US Patent 7,943,582: Canagliflozin Hemihydrate Claims, Exclusivity and Generic Risk

US Patent 7,943,582 protects a specific crystalline hemihydrate form of canagliflozin, the active ingredient in Invokana. Its strongest protection is directed to the solid-state form identified by powder X-ray diffraction and infrared spectroscopy. The patent also covers preparation of that form, pharmaceutical compositions containing it, and therapeutic use in diabetes and related metabolic disorders. It does not broadly claim every form of canagliflozin.

The patent issued May 17, 2011, from an application claiming a September 29, 2008 priority date. The listed patent term therefore runs nominally through September 29, 2029, subject to any applicable patent-term adjustment or regulatory exclusivity. FDA approval of Invokana occurred January 10, 2013.[1][2]

What drug does US Patent 7,943,582 protect?

The claimed compound is canagliflozin, chemically identified as:

1-(β-D-glucopyranosyl)-4-methyl-3-[5-(4-fluorophenyl)-2-thienylmethyl]benzene

Canagliflozin is a sodium-glucose cotransporter 2, or SGLT2, inhibitor. It reduces renal glucose reabsorption and increases urinary glucose excretion. The compound is marketed in the United States as:

Product	Active ingredient	Sponsor or manufacturer	FDA status
Invokana	Canagliflozin	Janssen Pharmaceuticals	Approved
Invokamet	Canagliflozin and metformin hydrochloride	Janssen Pharmaceuticals	Approved
Invokamet XR	Extended-release canagliflozin and metformin hydrochloride	Janssen Pharmaceuticals	Approved

The patent is directed to the crystalline hemihydrate form of canagliflozin used as the commercial active pharmaceutical ingredient, rather than to the SGLT2 mechanism in the abstract.

What is the scope of claim 1 of US Patent 7,943,582?

Claim 1 is the primary product claim. It covers:

• canagliflozin;
• in crystalline form;
• as a hemihydrate;
• without requiring the specific X-ray or infrared data recited in later claims.

The claim has three material limitations:

1. The compound must have the specified canagliflozin chemical structure.
2. It must be crystalline.
3. It must contain one-half molecule of water per molecule of canagliflozin, expressed as a hemihydrate.

Claim 1 does not expressly require a particular particle size, morphology, purity level, formulation, dosage strength, manufacturing scale, or pharmaceutical excipient.

The claim does not directly cover:

• amorphous canagliflozin;
• anhydrous crystalline canagliflozin;
• a different hydrate or solvate;
• a salt or co-crystal unless it also falls within the claimed chemical identity;
• a composition containing only a different canagliflozin solid form.

The central infringement issue is therefore solid-state identity. A generic manufacturer that makes or imports canagliflozin hemihydrate is exposed to claim 1 even if its tablets, excipients, particle size, or manufacturing process differ.

How do claims 2, 3 and 4 narrow the crystalline-form protection?

Claims 2 through 4 provide analytical definitions of the claimed hemihydrate.

Claim	Additional limitation	Practical significance
1	Crystalline canagliflozin hemihydrate	Broadest product claim
2	PXRD peaks at 4.36, 13.54, 16.00, 19.32 and 20.80° 2θ, each ±0.2° using CuKα radiation	Objective diffraction-based identification
3	Substantially the same PXRD pattern as Figure 1	Pattern-matching limitation
4	Substantially the same IR spectrum as Figure 2	Spectroscopic identity limitation

Claim 2 is particularly important for generic-drug analysis because powder X-ray diffraction can be used to characterize the API supplied in an ANDA product. The five listed peaks are not necessarily an exhaustive pattern. Claim 2 requires the claimed crystalline material to have the specified peaks within the stated tolerance.

Claims 3 and 4 use “substantially the same” language. That wording creates greater interpretive flexibility than the numerical peak limitations in claim 2, but it also raises fact-specific issues involving:

• peak position;
• relative intensity;
• instrument conditions;
• sample preparation;
• water content;
• polymorphic conversion during testing;
• whether minor additional peaks materially distinguish the tested material.

A product can fall within claim 1 even if it is not proven to satisfy claims 2, 3 or 4. The dependent claims create narrower, alternative enforcement positions rather than replacing claim 1.

What process does claim 5 protect?

Claim 5 covers a process for producing the claimed crystalline hemihydrate. The process requires:

1. forming a solution of canagliflozin; and
2. crystallizing the hemihydrate from that solution through precipitation or recrystallization.

The claim is not limited to a single solvent, temperature, concentration, cooling rate, seeding procedure, agitation profile, or drying condition. That breadth gives the claim potential relevance to commercial API processes using solution crystallization.

The process claim does not cover every method of manufacturing canagliflozin. A process that produces the compound through a route that does not involve forming a solution and crystallizing the hemihydrate may avoid literal infringement of claim 5, although the resulting product could still infringe claim 1.

Potential process evidence includes:

• solvent selection;
• water activity;
• crystallization temperature;
• supersaturation control;
• seeding;
• isolation and filtration;
• drying conditions;
• batch records and process-development reports;
• API solid-form characterization.

A manufacturer may avoid claim 5 while remaining exposed to the product claims if its final API is the claimed hemihydrate.

What pharmaceutical compositions are covered by claim 6?

Claim 6 covers a pharmaceutical composition comprising:

• an effective amount of the claimed crystalline canagliflozin hemihydrate; and
• a pharmaceutically acceptable carrier.

The claim can reach tablets, capsules, granules, powders, and other dosage forms containing the patented solid form. It is not limited to a specific dose or excipient system.

The carrier limitation is broad. Conventional excipients such as microcrystalline cellulose, lactose, croscarmellose sodium, magnesium stearate, and coating materials would generally be consistent with a pharmaceutical composition claim of this type.

Claim 6 may also be relevant to fixed-dose combinations. The presence of metformin or another active ingredient does not necessarily avoid infringement if the composition contains an effective amount of the patented canagliflozin hemihydrate.

The claim does not expressly require:

• immediate-release delivery;
• extended-release delivery;
• a particular tablet strength;
• a particular dissolution profile;
• a specific canagliflozin-to-metformin ratio.

Separate formulation or combination-product patents may impose additional barriers beyond claim 6.

What therapeutic uses are covered by claim 7?

Claim 7 covers administering the claimed hemihydrate to treat or delay the progression or onset of a broad set of metabolic and vascular conditions, including:

• diabetes mellitus;
• diabetic retinopathy;
• diabetic neuropathy;
• diabetic nephropathy;
• delayed wound healing;
• insulin resistance;
• hyperglycemia;
• hyperinsulinemia;
• elevated fatty acids;
• elevated glycerol;
• hyperlipidemia;
• obesity;
• hypertriglyceridemia;
• Syndrome X;
• diabetic complications;
• atherosclerosis; and
• hypertension.

This is a product-specific method-of-use claim. The administered material must be the claimed crystalline hemihydrate. A physician’s treatment of an approved diabetes indication may create practical infringement exposure for a manufacturer or supplier, but direct method-of-treatment enforcement against physicians is generally less commercially significant than product, composition, or inducement theories.

The breadth of the indication list exceeds the principal FDA-approved use of Invokana. Patent scope and FDA labeling scope are therefore different. A method claim can list conditions that are not all approved indications, while FDA labeling determines the legally authorized marketing claims.

When does US Patent 7,943,582 lose exclusivity?

Event	Date or status
Earliest stated priority	September 29, 2008
US application filing	September 29, 2009
US publication	2010
Patent issuance	May 17, 2011
FDA approval of Invokana	January 10, 2013
Nominal patent expiration	September 29, 2029
Small-molecule regulatory exclusivity	Expired
Patent status after expiration	Dependent on any applicable PTA, terminal disclaimer, litigation outcome or later patent

A patent expiration date does not guarantee immediate generic competition. ANDA approval depends on the applicant’s certification position, FDA review, litigation timing, settlements, manufacturing readiness, and any other unexpired listed patents.

Canagliflozin is a small molecule. Biosimilar exclusivity under the Public Health Service Act is not relevant. Generic applicants use the ANDA pathway under section 505(j) of the Federal Food, Drug, and Cosmetic Act.[3]

What is the Orange Book status of US Patent 7,943,582?

US Patent 7,943,582 has been associated with FDA-listed canagliflozin products, including Invokana-related products. Orange Book listing gives the patent regulatory significance because an ANDA applicant must address listed patents through:

• Paragraph I certification;
• Paragraph II certification;
• Paragraph III certification; or
• Paragraph IV certification.

For a patent that has not expired, an ANDA applicant generally must certify that the patent is invalid, unenforceable, or will not be infringed to make a Paragraph IV challenge.

The Orange Book listing does not itself establish patent validity or infringement. It identifies patents that the NDA holder has submitted to FDA as claiming the drug, a method of using the drug, or an approved product containing the drug.[4]

The exact commercial impact depends on whether the patent remains listed against:

• Invokana;
• Invokamet;
• Invokamet XR;
• a particular strength;
• a particular dosage form; or
• a specific approved indication.

Which companies are challenging canagliflozin patents?

Publicly disclosed ANDA challenges must be evaluated through FDA Orange Book records, Paragraph IV notices, district-court complaints, and settlement filings. The relevant competitive group includes generic manufacturers that may seek approval for canagliflozin tablets or canagliflozin/metformin products.

A Paragraph IV challenge to Patent 7,943,582 would most likely rely on one or more of these positions:

Challenge theory	Application to this patent
Noninfringement	The proposed API is not the claimed hemihydrate or does not meet the claim limitations
Invalidity for anticipation	The specific crystalline hemihydrate was previously disclosed
Invalidity for obviousness	The claimed form was an obvious solid-state selection
Indefiniteness	“Substantially the same” analytical language is challenged
Enablement or written description	The specification allegedly does not support the full claim scope
Process distinction	The applicant’s crystallization process does not practice claim 5
Formulation distinction	The finished product does not contain the patented solid form

For small-molecule products, the most consequential practical issue is usually whether the proposed API is the same protected form, not whether the finished tablet has a different appearance.

What patent landscape surrounds canagliflozin?

The commercial patent estate is broader than Patent 7,943,582. It can include several layers:

Compound patents

Earlier patent families may claim C-glucoside SGLT2 inhibitors, including canagliflozin and related analogues. Their expiration dates depend on priority claims, continuations, terminal disclaimers, and patent-term adjustments.

Crystalline-form patents

Patent 7,943,582 is the key form patent identified here. Other jurisdictions may contain corresponding applications, grant patents, divisional filings, or separate solid-form claims.

Manufacturing patents

Process families may cover:

• preparation of the aglycone;
• glycosylation;
• stereochemical control;
• purification;
• crystallization;
• hydrate formation;
• solvent exchange;
• particle engineering.

Manufacturing patents can create supply-chain risk even when a generic applicant designs around the final product claim.

Formulation patents

Potential formulation coverage includes:

• immediate-release tablets;
• extended-release combination products;
• canagliflozin/metformin dosage forms;
• dissolution control;
• excipient systems;
• tablet manufacturing processes.

A generic applicant may need to address these patents separately from Patent 7,943,582.

Method-of-use patents

Method claims may cover treatment of type 2 diabetes, cardiovascular risk, renal disease, or other conditions. Their relevance depends on the approved label, use code, skinny-label strategy, and inducement risk.

Combination-product patents

Invokamet and Invokamet XR present a separate patent landscape because they combine canagliflozin with metformin and, in the extended-release product, impose additional release-profile and formulation requirements.

How strong is the patent estate for Patent 7,943,582?

The estate is strongest against a generic manufacturer using commercial canagliflozin hemihydrate as its API.

Risk area	Assessment
Commercial API using the claimed hemihydrate	High
API using anhydrous or different polymorphic form	Fact-dependent and potentially lower
Tablet containing patented hemihydrate	High if claim 6 applies
Alternative crystallization process	May avoid claim 5 but not product claims
Amorphous API	Potential design-around, subject to conversion during manufacture or storage
Different hydrate or solvate	Potential design-around if analytically distinct
Biosimilar competition	Not applicable
FDA approval without patent resolution	Low before expiration unless certification or litigation permits approval
Post-expiration competition	Substantial, subject to other listed patents

The product claims provide stronger enforcement leverage than claim 5 because they do not require proof of the accused manufacturer’s confidential process. Claim 5 is commercially useful when process evidence is available, but it is more difficult to enforce against a third-party API supplier without discovery.

What generic launch scenarios exist for canagliflozin?

Launch after patent expiration

This is the lowest litigation-risk scenario. A generic applicant may seek approval with a Paragraph III certification and launch after the relevant patent expiration date, assuming no other blocking patents remain.

Paragraph IV launch after successful challenge

An applicant can seek approval before expiration by asserting that Patent 7,943,582 is invalid, unenforceable, or not infringed. Litigation may delay approval for up to the statutory 30-month period unless the case is resolved earlier.

Settlement-based launch

A patent settlement may permit an agreed launch date before September 2029. The commercial terms could include:

• an authorized generic arrangement;
• supply licensing;
• a delayed generic entry date;
• a covenant not to sue;
• restrictions on product forms or indications.

The Federal Trade Commission reviews pharmaceutical patent settlements for potential anticompetitive provisions.[5]

Form-specific design-around

A generic company could pursue a different solid form, but it must control the risk that the selected form converts into canagliflozin hemihydrate during drying, milling, tableting, storage, or dissolution.

What geographic coverage does the patent family provide?

US Patent 7,943,582 has territorial effect only in the United States. Corresponding international applications and national patents may protect the same hemihydrate in Europe, Japan, Canada, Australia, and other markets, but each jurisdiction requires separate analysis of:

• claim wording;
• priority validity;
• patent term;
• regulatory patent linkage;
• opposition or revocation proceedings;
• national court decisions;
• supplementary protection certificates.

The US patent cannot independently block manufacture, sale, or importation outside the United States. A global supplier must map the related family and confirm the status of each national member.

Key Takeaways

• US Patent 7,943,582 protects crystalline canagliflozin hemihydrate.
• Claim 1 is the principal product claim and does not require the specific PXRD or IR data in claims 2 through 4.
• Claims 2 through 4 provide analytical definitions based on PXRD and infrared spectroscopy.
• Claim 5 covers solution-based precipitation or recrystallization of the hemihydrate.
• Claim 6 reaches pharmaceutical compositions containing the patented form, including potential combination products.
• Claim 7 covers treatment of diabetes and a broad set of related metabolic and vascular conditions.
• The nominal patent expiration date is September 29, 2029.
• Canagliflozin is a small molecule, so biosimilar pathways do not apply.
• The principal generic risk is use of the patented hemihydrate as the commercial API.
• Separate compound, formulation, process, combination-product and method-of-use patents may affect launch timing.

FAQs About US Patent 7,943,582 and Canagliflozin

Is Patent 7,943,582 a compound patent for canagliflozin?

No. It is directed primarily to a crystalline hemihydrate form of canagliflozin. Earlier or related patent families may provide broader compound protection.

Can a generic company avoid Patent 7,943,582 by using amorphous canagliflozin?

Potentially, but only if the material remains amorphous and does not convert to the patented hemihydrate during API manufacture, formulation, storage, or use. The product claims require technical solid-form analysis.

Does Patent 7,943,582 cover Invokamet?

Claim 6 can potentially cover a composition containing canagliflozin hemihydrate and metformin, but Invokamet may also be subject to separate formulation and combination-product patents.

Does a Paragraph III certification permit early generic launch?

No. A Paragraph III certification generally defers approval until patent expiration. Early approval requires another legal pathway, such as a successful Paragraph IV challenge, a settlement permitting earlier entry, or an applicable exclusivity outcome.

Are crystalline-form patents enforceable against API suppliers?

Yes. Product claims can be enforced against making, using, selling, offering for sale, or importing the claimed crystalline material. Process claims may require separate evidence showing that the supplier practices the claimed crystallization steps.

References

1. U.S. Patent No. 7,943,582. (2011). Crystalline forms of 1-(β-D-glucopyranosyl)-4-methyl-3-[5-(4-fluorophenyl)-2-thienylmethyl]benzene. United States Patent and Trademark Office.

2. U.S. Food and Drug Administration. (2013). FDA approves Invokana to treat type 2 diabetes. FDA.

3. Federal Food, Drug, and Cosmetic Act, 21 U.S.C. § 355(j).

4. U.S. Food and Drug Administration. (2024). Approved drug products with therapeutic equivalence evaluations: Orange Book. FDA.

5. Federal Trade Commission. (2023). Agreements filed with the Federal Trade Commission under the Medicare Prescription Drug, Improvement, and Modernization Act of 2003. FTC.

Drugs Protected by US Patent 7,943,582

Applicant	Tradename	Generic Name	Dosage	NDA	Approval Date	TE	Type	RLD	RS	Patent No.	Patent Expiration	Product	Substance	Delist Req.	Patented / Exclusive Use	Submissiondate
Janssen Pharms	INVOKAMET XR	canagliflozin; metformin hydrochloride	TABLET, EXTENDED RELEASE;ORAL	205879-002	Sep 20, 2016		RX	Yes	No					Y
Janssen Pharms	INVOKAMET XR	canagliflozin; metformin hydrochloride	TABLET, EXTENDED RELEASE;ORAL	205879-001	Sep 20, 2016		RX	Yes	No					Y
Janssen Pharms	INVOKAMET XR	canagliflozin; metformin hydrochloride	TABLET, EXTENDED RELEASE;ORAL	205879-004	Sep 20, 2016		RX	Yes	Yes					Y
Janssen Pharms	INVOKAMET XR	canagliflozin; metformin hydrochloride	TABLET, EXTENDED RELEASE;ORAL	205879-003	Sep 20, 2016		RX	Yes	No					Y

Foreign Priority and PCT Information for Patent: 7,943,582

Foriegn Application Priority Data
Foreign Country	Foreign Patent Number	Foreign Patent Date
Japan	2006-327019	Dec 04, 2006

International Family Members for US Patent 7,943,582

Country	Patent Number	Estimated Expiration	Supplementary Protection Certificate	SPC Country	SPC Expiration
Argentina	064099
Argentina	107510
Argentina	118450
Argentina	129907