US Patent 9,155,705: Scope, Claim Construction, Expiration, and Linagliptin-Metformin Patent Landscape
US Patent 9,155,705 protects solid dosage forms combining linagliptin, metformin hydrochloride, and L-arginine. The patent is directed primarily to the composition and formulation of the linagliptin/metformin product marketed as Jentadueto. Its strongest commercial coverage is for tablets containing 2.5 mg linagliptin, metformin hydrochloride at conventional strengths, L-arginine, and specified excipients.
The patent does not broadly cover linagliptin, metformin, or their combination without L-arginine. A competing product that omits L-arginine, uses a non-solid dosage form, or falls outside the claimed formulation architecture may avoid literal infringement, subject to equivalents and other patents in the family.
What drug and product do the claims cover?
The lengthy chemical name in the claims is linagliptin, a dipeptidyl peptidase-4 inhibitor. The claimed metformin component is metformin hydrochloride.
The commercial product most closely aligned with the claims is Jentadueto, a fixed-dose combination of linagliptin and metformin hydrochloride marketed by Boehringer Ingelheim Pharmaceuticals and Eli Lilly in the United States. FDA-approved Jentadueto tablets contain 2.5 mg linagliptin combined with 500 mg, 850 mg, or 1,000 mg metformin hydrochloride, administered twice daily. Jentadueto XR uses extended-release metformin and is a separate dosage-form product requiring separate patent and regulatory analysis. [1]
| Claim element |
US 9,155,705 requirement |
| DPP-4 inhibitor |
Linagliptin |
| Linagliptin amount |
About 0.5 mg to about 10 mg |
| Metformin component |
Metformin hydrochloride |
| Metformin amount |
About 100 mg to about 1,500 mg in claim 4 |
| L-arginine |
About 1 mg to about 50 mg |
| Dosage form |
Solid pharmaceutical composition; several claims require a tablet |
| Excipients |
At least one pharmaceutical excipient |
| Specific formulation options |
Fillers, binders, lubricants, glidants, film coats and specified particle size |
| Commercially relevant strength |
2.5 mg linagliptin with 500, 850 or 1,000 mg metformin |
What does independent claim 1 protect?
Claim 1 is the principal composition claim. A product must contain each of the following elements to present a literal infringement case:
- Linagliptin in an amount from about 0.5 mg to about 10 mg.
- Metformin hydrochloride.
- A pharmaceutical excipient.
- L-arginine in an amount from about 1 mg to about 50 mg.
- A solid pharmaceutical composition.
The transitional phrase “comprising or made from” creates broad open-ended coverage. A composition may contain additional active ingredients or excipients and still fall within the claim if it contains the listed elements.
The claim does not require:
- A particular tablet manufacturing process.
- A particular ratio of linagliptin to metformin.
- A particular metformin strength.
- A particular excipient.
- A particular tablet coating.
- A particular particle size.
Those limitations appear in dependent claims or separate claims.
The most important limitation is L-arginine. A solid linagliptin/metformin product without L-arginine would not literally satisfy claim 1. The claim also requires metformin hydrochloride, rather than merely metformin in an unspecified form.
How do claims 2 through 12 narrow the formulation?
Claims 2 through 12 define commercially relevant dosage and dosage-form variations.
| Claim |
Added limitation |
| 2 |
Linagliptin strength of 0.5, 1, 2.5, 5 or 10 mg |
| 3 |
Linagliptin strength of 2.5 mg |
| 4 |
Metformin hydrochloride from about 100 mg to about 1,500 mg |
| 5 |
Metformin strength of 250, 500, 625, 750, 850 or 1,000 mg |
| 6 |
Metformin strength of 500, 850 or 1,000 mg |
| 7 |
Linagliptin-to-L-arginine weight ratio from about 1:20 to about 10:1 |
| 8 |
Excipient selected from fillers, binders, lubricants or glidants |
| 9 |
Copovidone as binder |
| 10 |
Corn starch, magnesium stearate or colloidal anhydrous silica |
| 11 |
Monolayer, bilayer, press-coated or film-coated tablet |
| 12 |
Tablet with a film coat |
Claim 3 is particularly important because it maps directly to the 2.5 mg linagliptin strength used in Jentadueto. Claim 6 maps to the 500 mg, 850 mg and 1,000 mg metformin strengths approved for the immediate-release combination product.
Claims 9 and 10 create a formulation-specific layer around common tablet excipients. Copovidone, corn starch, magnesium stearate and colloidal anhydrous silica are conventional excipients, but their presence becomes legally relevant when combined with all limitations inherited from claim 1.
What do claims 13 through 25 add?
Claims 13 through 25 create additional composition, process and tablet embodiments.
Claim 13: defined excipient classes
Claim 13 requires linagliptin, metformin hydrochloride, L-arginine, a filler, a binder, a glidant and a lubricant. It is narrower than claim 1 because it requires all four excipient categories.
Claim 14: particle-size limitation
Claim 14 requires a linagliptin particle-size distribution of X90 below 200 micrometers. This limitation can matter in a generic formulation review because particle-size data may be located in manufacturing specifications rather than public product labeling.
A generic manufacturer could avoid literal infringement by using a different particle-size distribution, although the commercial and bioequivalence consequences would need separate evaluation.
Claim 15: process-defined composition
Claim 15 covers a composition made by incorporating the active ingredients and L-arginine into an excipient selected from:
- D-mannitol;
- corn starch;
- pregelatinized starch;
- copovidone;
- magnesium stearate; and
- colloidal anhydrous silica.
This claim combines product and process language. In an infringement analysis, the manufacturing process may be material because the claim does not merely recite the final composition. Evidence from manufacturing records, batch instructions and regulatory submissions could become relevant.
Claims 16 through 18: excipient combinations
These claims progressively require:
- A filler;
- A filler and binder; or
- A filler, binder and lubricant.
Claims 19 through 24: tablets and specific excipients
Claim 19 requires a tablet containing the claim 1 components. Claims 20 through 23 add increasing excipient requirements. Claim 24 identifies a specific excipient combination:
- Corn starch;
- Copovidone;
- Magnesium stearate; and
- Colloidal anhydrous silica.
Claim 24 is one of the more formulation-specific claims and is more vulnerable to design-around through substitution of excipients, provided the substitute formulation does not fall within another claim or an equivalent formulation.
Claim 25: apparent metformin-strength inconsistency
Claim 25 specifies approximately 2.5 mg linagliptin, but recites approximately 0.5 mg to approximately 10 mg metformin hydrochloride. That metformin range is inconsistent with the conventional metformin strengths and with claim 4’s 100 mg to 1,500 mg range.
As written, claim 25 must be analyzed according to its issued text. The dependent claim also incorporates the limitations of claim 1. Its practical commercial significance is limited because a product containing standard metformin strengths such as 500 mg, 850 mg or 1,000 mg would not fall within the express 0.5 mg-to-10 mg metformin range in claim 25.
How broad is the patent’s literal infringement scope?
The patent has meaningful but bounded coverage.
Broad features
Claim 1 is broad because it:
- Uses “comprising” language;
- Does not specify a particular excipient;
- Does not require a particular tablet design;
- Does not require a specific metformin strength;
- Does not require a specific manufacturing process; and
- Covers a relatively broad linagliptin range.
A solid tablet with additional ingredients can remain within claim 1 if it contains linagliptin, metformin hydrochloride, L-arginine and an excipient in the required amounts.
Narrow features
The principal restrictions are:
- L-arginine is mandatory;
- The dosage form must be solid;
- Metformin must be present as metformin hydrochloride;
- Linagliptin must be within the claimed dosage range;
- L-arginine must be within the claimed range; and
- Certain dependent claims require specific excipient classes or tablet structures.
The patent therefore does not block every linagliptin/metformin product. It targets a particular solid fixed-dose formulation strategy.
What formulations are protected by US 9,155,705?
The highest-risk formulation profile is an immediate-release tablet containing:
- 2.5 mg linagliptin;
- 500 mg, 850 mg or 1,000 mg metformin hydrochloride;
- Approximately 1 mg to 50 mg L-arginine;
- A filler such as mannitol or starch;
- Copovidone;
- Magnesium stearate;
- Colloidal anhydrous silica; and
- A film coating.
A product with that profile may implicate claims 1, 3, 6, 9, 10, 12, 19 and 24, depending on its precise composition and manufacturing process.
The patent’s claims also reach other strengths, including 0.5 mg, 1 mg, 5 mg and 10 mg linagliptin, even though those strengths may not correspond to the principal U.S. commercial presentation.
When does US Patent 9,155,705 lose exclusivity?
US Patent 9,155,705 issued on October 13, 2015. Its underlying U.S. application claims priority to a 2010 filing period, and the ordinary 20-year patent term is expected to place expiration in late 2030, subject to patent-term adjustment, terminal disclaimers or other USPTO-record changes. [2]
| Event |
Date or period |
| U.S. patent application period |
2010 |
| Patent grant |
October 13, 2015 |
| Expected ordinary term endpoint |
Approximately late 2030 |
| Possible adjustment |
Patent-term adjustment or terminal disclaimer must be checked in the USPTO file |
| Regulatory exclusivity |
Separate from patent term and product-specific |
Patent expiration does not by itself establish immediate generic launch freedom. Other linagliptin, metformin, formulation, method-of-use or process patents may create separate barriers. FDA regulatory exclusivity also must be assessed independently.
What is the Orange Book status of the patent?
The Orange Book is the relevant FDA database for patents submitted for approved small-molecule products. Jentadueto and related linagliptin products have had multiple patents associated with the linagliptin franchise, including patents directed to the active compound, combinations and formulations. The specific listing status of US 9,155,705 should be read against the current Orange Book entry for the relevant NDA and dosage form. [3]
An Orange Book listing matters because it can trigger a Paragraph IV notice and a potential 30-month stay if the listed patent holder brings suit within the statutory period. A listed patent does not establish validity or infringement. It identifies a patent submitted by the NDA holder or sponsor as relevant to the approved product.
What Paragraph IV challenges and litigation risks exist?
A generic applicant seeking approval before patent expiry would likely use an ANDA with one or more patent certifications. For this patent, the most commercially relevant challenges would target:
- The requirement for L-arginine;
- The “about” boundaries for linagliptin and L-arginine;
- Whether the proposed product is a solid pharmaceutical composition;
- The construction of “comprising or made from”;
- The particle-size limitation in claim 14;
- The process limitations in claim 15;
- Anticipation or obviousness based on earlier linagliptin/metformin formulations; and
- Written-description or enablement issues for the full dosage and excipient scope.
A generic applicant could pursue a Paragraph IV certification asserting invalidity, noninfringement or both. It could also submit a Paragraph III certification and defer launch until expiration if the patent remains listed and commercially material.
The most credible noninfringement route is a formulation that omits L-arginine. The strongest invalidity route would require prior-art evidence showing the claimed combination of linagliptin, metformin hydrochloride, L-arginine and the relevant solid formulation features before the applicable priority date.
How does the patent compare with broader linagliptin patents?
US 9,155,705 is narrower than core composition-of-matter patents covering linagliptin itself. Core compound patents can block use of the active ingredient across multiple dosage forms and combinations. By contrast, this patent is product-specific and depends on L-arginine and solid dosage-form limitations.
| Patent category |
Typical scope |
Relevance to generic entry |
| Linagliptin compound patent |
Linagliptin and related compounds |
Broadest active-ingredient barrier |
| Linagliptin manufacturing patent |
Processes and intermediates |
Relevant to API sourcing |
| Linagliptin/metformin combination patent |
Co-administration or fixed-dose combinations |
Relevant to combination products |
| US 9,155,705 |
Solid composition with linagliptin, metformin HCl and L-arginine |
High relevance to Jentadueto-like tablets |
| Formulation patent |
Excipients, particle size, coating or release profile |
Product-specific barrier |
| Method-of-use patent |
Treatment of type 2 diabetes or related conditions |
Relevant where the ANDA label overlaps |
The patent is strongest against a close copy of the reference formulation. It is weaker against a product that changes the salt, removes L-arginine, uses a different dosage form, or adopts materially different excipient and manufacturing parameters.
What manufacturing and IP barriers remain after patent expiry?
Manufacturing barriers may remain even if the patent expires. A generic manufacturer must establish:
- Linagliptin API identity and purity;
- Particle-size control;
- Content uniformity at low linagliptin loading;
- Compatibility of linagliptin with metformin hydrochloride;
- Tablet hardness and dissolution;
- Stability in the presence of L-arginine;
- Bioequivalence to the reference product; and
- Compliance with FDA’s current quality and manufacturing requirements.
L-arginine can affect tablet microenvironment, dissolution and stability. A formulation that omits it may avoid this patent but still require a new excipient strategy and bioequivalence package.
What is the commercial exposure?
Jentadueto addresses the type 2 diabetes market and competes with other DPP-4 inhibitor/metformin combinations, including Janumet and Janumet XR, which contain sitagliptin and metformin, and Kombiglyze XR, which contains saxagliptin and metformin.
The relevant commercial exposure is the revenue associated with linagliptin/metformin fixed-dose tablets, not the full linagliptin franchise. A successful Paragraph IV launch could affect Jentadueto sales while leaving Tradjenta, Jentadueto XR and other linagliptin products subject to separate patent and regulatory analyses.
Key Takeaways
- US 9,155,705 is a formulation patent centered on solid linagliptin/metformin hydrochloride compositions containing L-arginine.
- Claim 1 requires all four core elements: linagliptin, metformin hydrochloride, an excipient and L-arginine.
- Claims 3 and 6 directly cover the commercially important 2.5 mg linagliptin and 500 mg, 850 mg and 1,000 mg metformin strengths.
- Claims 9, 10 and 24 add common excipients including copovidone, corn starch, magnesium stearate and colloidal anhydrous silica.
- Claim 14 adds an X90 particle-size limitation below 200 micrometers.
- Claim 15 creates potential process-based infringement exposure.
- The expected ordinary patent term extends to approximately late 2030, subject to USPTO term adjustments and disclaimers.
- The strongest design-around is omission of L-arginine, but other linagliptin and combination patents may remain relevant.
- A Paragraph IV strategy would likely focus on L-arginine, prior art, claim construction, particle size and manufacturing-process limitations.
- US 9,155,705 is materially narrower than a linagliptin composition-of-matter patent but potentially significant for a Jentadueto-like tablet.
FAQs
Does US 9,155,705 cover linagliptin alone?
No. The claims require metformin hydrochloride, L-arginine and a pharmaceutical excipient in a solid composition.
Does the patent cover a linagliptin/metformin tablet without L-arginine?
Not literally under claim 1. The omission of L-arginine would remove a required claim element, although other patents or an equivalents theory could remain relevant.
Does US 9,155,705 cover Jentadueto XR?
The patent’s claims are directed to solid compositions and tablets, but Jentadueto XR has extended-release formulation characteristics that require separate claim-chart and Orange Book analysis.
Can a generic use different excipients and avoid the patent?
Possibly. Different excipients may avoid claims requiring copovidone, corn starch, magnesium stearate or colloidal anhydrous silica. Claim 1 remains broader because it requires only a pharmaceutical excipient.
Is L-arginine a patentable distinction in the formulation?
It can be, provided the issued claims are valid and the formulation limitations satisfy patentability requirements. Its commercial importance arises because it is mandatory in the broadest composition claim.
References
-
U.S. Food and Drug Administration. (n.d.). Jentadueto: Prescribing information. FDA Drugs@FDA database.
-
United States Patent and Trademark Office. (2015). U.S. Patent No. 9,155,705, pharmaceutical composition claims for linagliptin and metformin hydrochloride. USPTO Patent Center.
-
U.S. Food and Drug Administration. (n.d.). Approved drug products with therapeutic equivalence evaluations: Orange Book. FDA.
