DCT
1:17-cv-01844
Amgen Inc v. Torrent Pharma Ltd
Key Events
Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Amgen Inc. (Delaware)
- Defendant: Torrent Pharmaceuticals Ltd. (India) and Torrent Pharma, Inc. (Delaware)
- Plaintiff’s Counsel: Morris, Nichols, Arsht & Tunnell LLP
- Case Identification: 1:17-cv-01844, D. Del., 12/22/2017
- Venue Allegations: Venue is alleged to be proper in Delaware because Defendant Torrent Pharma, Inc. is a Delaware corporation, and its parent, Torrent Ltd., directs its operations and regularly transacts business in the state. The complaint also notes that Defendants have previously availed themselves of Delaware courts in other litigation without objecting to personal jurisdiction.
- Core Dispute: Plaintiff alleges that Defendants' filing of an Abbreviated New Drug Application (ANDA) for generic cinacalcet hydrochloride tablets infringes a patent related to a rapid dissolution formulation of the drug.
- Technical Context: The patent-in-suit relates to pharmaceutical formulations designed to improve the dissolution rate and bioavailability of cinacalcet, a drug used to treat disorders related to the parathyroid glands.
- Key Procedural History: This action was initiated under the Hatch-Waxman Act following Plaintiff Amgen's receipt of a Paragraph IV certification letter from Defendant Torrent Ltd. The letter asserted that U.S. Patent No. 9,375,405 is invalid or would not be infringed by Torrent's proposed generic product. The patent-in-suit is listed in the FDA's "Orange Book" as covering Amgen's product, SENSIPAR®.
Case Timeline
| Date | Event |
|---|---|
| 2003-09-12 | ’405 Patent Priority Date |
| 2004-03-08 | Amgen receives FDA approval for SENSIPAR® (NDA 21-688) |
| 2011-02-25 | Amgen receives FDA approval for expanded SENSIPAR® use |
| 2016-06-28 | U.S. Patent No. 9,375,405 issues |
| 2017-11-09 | Torrent Ltd. sends Paragraph IV certification letter |
| 2017-12-22 | Complaint for patent infringement filed |
II. Technology and Patent(s)-in-Suit Analysis
- Patent Identification: U.S. Patent No. 9,375,405, "Rapid Dissolution Formulation of a Calcium Receptor-Active Compound," issued June 28, 2016.
The Invention Explained
- Problem Addressed: The patent's background section notes that calcium receptor-active compounds like cinacalcet hydrochloride can be "insoluble or sparingly soluble in water," particularly at neutral pH (’405 Patent, col. 1:10-14). This poor solubility can limit formulation options and result in low or inconsistent bioavailability of the drug when administered to a patient (’405 Patent, col. 1:18-21).
- The Patented Solution: The invention claims a specific pharmaceutical composition designed to overcome this solubility issue by creating a "rapid dissolution formulation" (’405 Patent, Title). The solution is not merely the active ingredient, but its combination in specific proportions with a set of pharmaceutically acceptable excipients, including particular diluents, binders, and disintegrants, to achieve a "defined dissolution profile" (’405 Patent, col. 1:30-32). The specification describes manufacturing processes, such as granulation, that contribute to this profile (’405 Patent, col. 9:42-45).
- Technical Importance: For poorly soluble drugs, developing a formulation that ensures rapid and complete dissolution in the gastrointestinal tract is a critical step in creating a commercially viable and therapeutically effective oral medication (’405 Patent, col. 1:21-24).
Key Claims at a Glance
- The complaint asserts at least independent claim 1 (’405 Patent, col. 12:16-39; Compl. ¶38).
- The essential elements of independent claim 1 are:
- A pharmaceutical composition comprising: from about 10% to about 40% by weight of cinacalcet HCl in an amount of from about 20 mg to about 100 mg;
- from about 45% to about 85% by weight of a diluent selected from a specified group that includes microcrystalline cellulose and starch;
- from about 1% to about 5% by weight of a binder selected from a specified group that includes povidone; and
- from about 1% to about 10% by weight of a disintegrant selected from a specified group that includes crospovidone.
- A purpose clause stating the composition is for the treatment of specific conditions, including hyperparathyroidism.
- The complaint does not explicitly reserve the right to assert dependent claims.
III. The Accused Instrumentality
- Product Identification: The accused instrumentalities are Defendants' proposed generic "cinacalcet hydrochloride tablets (EQ 30 mg base, EQ 60 mg base, and EQ 90 mg base)" for which Torrent Ltd. filed Abbreviated New Drug Application (“ANDA”) No. 210781 with the FDA (Compl. ¶7).
- Functionality and Market Context:
- The complaint alleges the accused products are generic versions of Amgen’s SENSIPAR® tablets (Compl. ¶25). As such, their function is to deliver cinacalcet hydrochloride to treat conditions like secondary hyperparathyroidism in patients with chronic kidney disease (Compl. ¶¶20-21).
- The active ingredient in the accused ANDA products is alleged to be cinacalcet hydrochloride (Compl. ¶35). The complaint alleges that Defendants seek approval to market these products prior to the expiration of the ’405 patent, after having reviewed commercial and economic information regarding SENSIPAR® (Compl. ¶¶25, 27).
IV. Analysis of Infringement Allegations
No probative visual evidence provided in complaint. The complaint does not contain a claim chart or provide specific details linking the formulation of the accused ANDA product to the claim elements of the ’405 patent beyond identifying the active ingredient and dosage strengths. The infringement theory is based on the statutory act of filing an ANDA for a product that, if approved, would allegedly meet all limitations of the asserted claim.
’405 Patent Infringement Allegations
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A pharmaceutical composition comprising: (a) from about 10% to about 40% by weight of cinacalcet HCl in an amount of from about 20 mg to about 100 mg | The accused ANDA product is a pharmaceutical composition containing cinacalcet hydrochloride in 30 mg, 60 mg, and 90 mg tablet strengths. | ¶¶7, 35, 38 | col. 12:18-20 |
| (b) from about 45% to about 85% by weight of a diluent selected from the group consisting of microcrystalline cellulose, starch...and mixtures thereof | The complaint alleges infringement, which suggests the possibility that the ANDA product contains a claimed diluent within the specified weight percentage. | ¶¶38, 43 | col. 12:21-26 |
| (c) from about 1% to about 5% by weight of at least one binder selected from the group consisting of povidone...and mixtures thereof | The complaint alleges infringement, which suggests the possibility that the ANDA product contains a claimed binder within the specified weight percentage. | ¶¶38, 43 | col. 12:27-32 |
| (d) from about 1% to 10% by weight of at least one disintegrant selected from the group consisting of crospovidone...and mixtures thereof | The complaint alleges infringement, which suggests the possibility that the ANDA product contains a claimed disintegrant within the specified weight percentage. | ¶¶38, 43 | col. 12:33-37 |
- Identified Points of Contention:
- Scope Questions: A central issue will be factual: does the specific formulation detailed in Torrent’s confidential ANDA contain the exact types of diluents, binders, and disintegrants recited in the Markush groups of Claim 1?
- Technical Questions: Does the accused generic formulation, as a whole, meet all the claimed weight-percentage limitations for each category of ingredient? The infringement analysis will require a direct, quantitative comparison between the patent’s claims and the confidential ANDA filing, which is not available in the complaint.
V. Key Claim Terms for Construction
The complaint does not provide sufficient detail for a definitive analysis of likely claim construction disputes. However, based on the structure of Claim 1, the following term may become a focus.
- The Term: "wherein the composition is for the treatment of at least one of hyperparathyroidism, hyperphosphonia, hypercalcemia, and elevated calcium phosphorus product" (’405 Patent, col. 12:38-42).
- Context and Importance: This "wherein" clause appears at the end of the claim. Practitioners may focus on this term because its classification as either a limiting claim element or a non-limiting statement of intended use could impact the scope of the claim. If the clause is found to be limiting, it could potentially introduce an additional element that Amgen must prove is met by the accused product's intended use.
- Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation (Non-Limiting): A party may argue that the inventive aspect of the claim lies in the physical composition (the specific ingredients and their weight percentages), and that the "wherein" clause merely describes a suitable or intended use without imposing a separate limitation on the composition itself.
- Evidence for a Narrower Interpretation (Limiting): A party may argue that the clause is essential to "breathe life and meaning" into the claim, particularly as the patent is Orange Book-listed for these specific indications. The specification's discussion of treating hyperparathyroidism (’405 Patent, col. 4:16-20) could be cited to suggest the stated purpose is integral to the definition of the claimed invention, not merely contextual.
VI. Other Allegations
- Indirect Infringement: The complaint alleges that upon FDA approval, Defendants' commercial manufacture, use, and sale of the ANDA products will induce and/or contribute to the infringement of at least claim 1 of the ’405 patent (Compl. ¶43). The factual basis for knowledge and intent appears to be the act of filing the ANDA to market a generic equivalent for the same indications as the patented SENSIPAR® product.
- Willful Infringement: The complaint does not use the word "willful" but alleges that Defendants were aware of the ’405 patent at the time they sent the Paragraph IV notification (Compl. ¶29). This alleged pre-suit knowledge, combined with the continuation of allegedly infringing activities after the complaint was filed, could form the basis for a future claim of willful infringement. The complaint requests a declaration that the case is "exceptional" under 35 U.S.C. § 285 (Compl. p. 9, ¶D).
VII. Analyst’s Conclusion: Key Questions for the Case
A central evidentiary question will be one of "formulation identity": does the specific composition detailed in Torrent’s confidential ANDA—including the precise identity and weight percentages of its active ingredient and all excipients—fall within the literal boundaries of the asserted claims of the ’405 patent?
The case will likely turn on the question of "validity": Torrent has certified that the ’405 patent is invalid (Compl. ¶28). A primary issue for the court will therefore be whether the claimed formulation, which combines a known active ingredient with known categories of pharmaceutical excipients in specific ratios, would have been obvious to a person of ordinary skill in the art at the time of the invention.