DCT
2:18-cv-02545
Sun Pharmaceutical Industries Ltd v. Saptalis Pharma LLC
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Sun Pharmaceutical Industries Ltd. (India) and Ranbaxy Signature, LLC (Delaware)
- Defendant: Saptalis Pharmaceuticals, LLC (Delaware)
- Plaintiff’s Counsel: Winston & Strawn LLP
- Case Identification: 2:18-cv-02545, E.D.N.Y., 04/30/2018
- Venue Allegations: Venue is alleged to be proper because the Defendant's principal place of business is located within the Eastern District of New York.
- Core Dispute: Plaintiff alleges that Defendant’s filing of an Abbreviated New Drug Application (ANDA) for a generic liquid metformin oral solution constitutes an act of infringement of a patent covering Plaintiff's branded drug, RIOMET®.
- Technical Context: The technology concerns liquid pharmaceutical formulations of metformin, a widely prescribed oral medication for managing Type II diabetes.
- Key Procedural History: This is a Hatch-Waxman action triggered by Defendant's filing of ANDA No. 211309. The complaint states that the patent-in-suit is listed in the FDA’s "Orange Book" for RIOMET® and that Plaintiffs received a notice letter from the Defendant regarding the ANDA filing on or about March 17, 2018.
Case Timeline
| Date | Event |
|---|---|
| 2000-08-07 | ’957 Patent Priority Date |
| 2005-05-10 | ’957 Patent Issue Date |
| 2018-03-17 | Plaintiffs Receive Saptalis's ANDA Notice Letter |
| 2018-04-30 | Complaint Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 6,890,957 - “Liquid Formulation of Metformin”
The Invention Explained
- Problem Addressed: The patent describes that metformin, a common anti-diabetic drug, is typically sold as a large, bitter-tasting tablet that is difficult to swallow, especially for children and certain adults. (’957 Patent, col. 2:24-36). Creating a palatable liquid version is challenging because conventional taste-masking agents like sugar, alcohol, and certain sodium salts are detrimental to diabetic patients. (’957 Patent, col. 2:42-52).
- The Patented Solution: The invention claims to solve this by creating a sugar-free, alcohol-free liquid formulation. The solution uses a specific combination of ingredients, including a sweetener that does not affect blood glucose levels, a polyhydroxy alcohol to provide a syrupy texture and help mask the bitterness, and a buffer system comprising a mineral acid and a bicarbonate salt to maintain a specific pH range. (’957 Patent, Abstract; col. 3:1-26).
- Technical Importance: This technology provided a method for creating a liquid metformin product suitable for diabetic patients who have difficulty with solid dosage forms, potentially improving patient compliance. (’957 Patent, col. 10:35-40).
Key Claims at a Glance
- The complaint asserts at least independent Claim 1. (Compl. ¶20).
- The essential elements of Claim 1 are:
- A liquid pharmaceutical composition for oral administration comprising a therapeutically effective amount of metformin or its salt.
- A sweetener that does not increase blood glucose level.
- A polyhydroxy alcohol present in an amount of about 15% to 55% by weight.
- A mineral acid and a bicarbonate salt, both present in sufficient amounts to maintain the pH between about 4.0 and 9.0.
- A pharmaceutically acceptable liquid carrier.
- The complaint also alleges infringement of "one or more claims" of the patent, suggesting a reservation of rights to assert other claims, including dependent claims. (Compl. ¶22).
III. The Accused Instrumentality
Product Identification
The accused instrumentality is the "Saptalis ANDA Product," a generic version of RIOMET® (metformin hydrochloride) oral solution, 500 mg/5 mL, for which Saptalis has filed ANDA No. 211309. (Compl. ¶¶ 1, 5, 11).
Functionality and Market Context
The product is a liquid formulation of metformin hydrochloride intended for oral administration. (Compl. ¶1). The complaint alleges that the Saptalis ANDA relies on the New Drug Application (NDA) for RIOMET® and contains data intended to demonstrate the bioequivalence of the Saptalis ANDA Product with RIOMET®. (Compl. ¶16). Upon expected FDA approval, Saptalis allegedly intends to market and distribute the product to pharmacies, hospitals, and other end users. (Compl. ¶15).
No probative visual evidence provided in complaint.
IV. Analysis of Infringement Allegations
’957 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| a liquid pharmaceutical composition for oral administration which comprises a therapeutically effective amount of metformin or its pharmaceutically acceptable salt; | The complaint alleges on information and belief that the Saptalis ANDA Product is a liquid oral formulation containing metformin. | ¶20 | col. 15:10-14 |
| a sweetener that does not increase the blood glucose level of a subject after ingestion thereof; | The Saptalis ANDA Product is alleged to contain a sweetener that does not increase blood glucose levels. | ¶20 | col. 15:15-17 |
| a polyhydroxy alcohol present in an amount of about 15 to about 55% by weight; | The Saptalis ANDA Product is alleged to contain a polyhydroxy alcohol in the claimed concentration range. | ¶20 | col. 15:18-20 |
| a mineral acid and bicarbonate salt both present in sufficient amounts to maintain the pH of the composition in the range of about 4.0 to about 9.0; | The Saptalis ANDA Product is alleged to contain both a mineral acid and a bicarbonate salt to maintain the pH in the claimed range. | ¶20 | col. 15:21-24 |
| and a pharmaceutically acceptable liquid carrier. | The Saptalis ANDA Product is alleged to contain a pharmaceutically acceptable liquid carrier. | ¶20 | col. 15:25-26 |
Identified Points of Contention
- Technical Questions: A key evidentiary question will be whether the specific formulation detailed in Saptalis's confidential ANDA actually contains every element recited in Claim 1. For example, what evidence supports the allegation that the Saptalis product contains a "polyhydroxy alcohol" in the specific weight percentage of "about 15 to about 55%," or that it uses both a "mineral acid" and a "bicarbonate salt" to control pH? (Compl. ¶20). The complaint's reliance on "information and belief" suggests that discovery of the ANDA's contents will be central to resolving these factual issues.
- Scope Questions: The use of the term "about" in Claim 1 for both the concentration of the polyhydroxy alcohol and the pH range raises a question of claim scope. The parties may dispute how much deviation from the stated numerical ranges is permissible under the term "about."
V. Key Claim Terms for Construction
The Term: "polyhydroxy alcohol"
Context and Importance
The identity and concentration of this excipient is a central element of the claimed composition. Practitioners may focus on this term because the defendant could argue that its chosen excipient does not fall within the patent's definition of "polyhydroxy alcohol," or that the patent’s definition is limited to certain preferred embodiments.
Intrinsic Evidence for Interpretation
- Evidence for a Broader Interpretation: The specification defines the term as "any organic polyalcohol containing more than one hydroxy group thereon" and provides a non-exhaustive list of examples including glycols, glycerin, and sorbitol. (’957 Patent, col. 3:61-65).
- Evidence for a Narrower Interpretation: The specification also expresses a preference that the polyol is "not a sugar (carbohydrate) or sugar alcohol," later listing sorbitol (a sugar alcohol) as an example of a polyol. (’957 Patent, col. 4:16-17, col. 3:65). A party could argue these statements create an ambiguity or limit the scope to non-sugar-alcohol polyols.
The Term: "maintain the pH"
Context and Importance
Claim 1 requires that both a mineral acid and a bicarbonate salt be present in sufficient amounts to "maintain the pH." This term is critical because infringement requires not just the presence of these two components, but that they perform this specific function.
Intrinsic Evidence for Interpretation
- Evidence for a Broader Interpretation: A party could argue that this phrase simply means the final formulation, containing both components, has a pH within the recited range.
- Evidence for a Narrower Interpretation: The specification describes a specific belief about the mechanism: "it is believed that the mineral acid and bicarbonate salts present with the metformin, causes in-situ formation and release of effervescent gas (carbon dioxide, which carbonation helps in the taste masking...)." (’957 Patent, col. 7:50-55). A party could argue that "maintain the pH" requires this active, effervescent buffering system and that a formulation where one component is inert or fully reacted pre-formulation would not meet this limitation.
VI. Other Allegations
Indirect Infringement
The complaint alleges inducement of infringement, stating that Saptalis's proposed prescribing instructions will encourage healthcare professionals and end users to directly infringe the ’957 patent. (Compl. ¶22). It is alleged Saptalis will do so with knowledge of the patent and of its encouragement of infringing acts. (Compl. ¶22).
Willful Infringement
The complaint asserts that Saptalis had "actual and constructive knowledge" of the ’957 patent before filing its ANDA. (Compl. ¶23). It further alleges that Saptalis has "no reasonable basis" for its non-infringement position, which forms a basis for willfulness and a request for enhanced damages and attorneys' fees in an "exceptional case." (Compl. ¶¶ 24, 25).
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of compositional identity: does the generic formulation described in Saptalis's confidential ANDA contain every ingredient in the concentrations and combinations required by Claim 1 of the ’957 patent? The case will depend heavily on discovery into the precise details of the accused product's formulation.
- A second key question will be one of functional interpretation: must the "mineral acid and bicarbonate salt" combination actively create an in-situ effervescent reaction to "maintain the pH" as described in the patent's specification, or is their mere presence in a final formulation with the claimed pH sufficient to meet the claim limitation? The court’s construction of this functional language may be dispositive.