DCT
1:17-cv-01807
Amgen Inc v. Watson Laboratories Inc
Key Events
Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Amgen Inc. (Delaware)
- Defendant: Watson Laboratories, Inc. (Nevada) and Actavis Pharma, Inc. (Delaware)
- Plaintiff’s Counsel: Morris, Nichols, Arsht & Tunnell LLP
- Case Identification: 1:17-cv-01807, D. Del., 12/15/2017
- Venue Allegations: Venue is alleged to be proper based on Defendant Actavis Pharma, Inc. being a Delaware corporation, Defendant Watson Laboratories, Inc.’s business activities within Delaware, and Defendants having previously availed themselves of Delaware courts without objecting to jurisdiction.
- Core Dispute: Plaintiff alleges that Defendants' submission of an Abbreviated New Drug Application (ANDA) for generic cinacalcet hydrochloride tablets constitutes an act of infringement of a patent covering a rapid dissolution formulation for that compound.
- Technical Context: The technology relates to pharmaceutical formulations designed to improve the dissolution and bioavailability of cinacalcet, a drug used to treat disorders related to the parathyroid glands, particularly in patients with chronic kidney disease.
- Key Procedural History: This action arises under the Hatch-Waxman Act, triggered by Defendants’ submission of ANDA No. 202416 to the FDA. The complaint alleges that the patent-in-suit issued after Defendants’ predecessor filed the ANDA and that Defendants had knowledge of the patent through its listing in the FDA’s Orange Book, prior litigation on a different ANDA, and direct communications between counsel, but failed to provide a required certification for the patent-in-suit.
Case Timeline
| Date | Event |
|---|---|
| 2003-09-12 | ’405 Patent Priority Date |
| 2004-03-08 | FDA approves Amgen's New Drug Application for SENSIPAR® |
| 2011-03-23 | Date of letter notifying Amgen of ANDA filing for generic SENSIPAR® |
| 2016-06-28 | U.S. Patent No. 9,375,405 issues |
| 2016-07-22 | ’405 Patent listed in the FDA Orange Book |
| 2017-09-12 | Counsel for Teva (Defendants' parent) and Amgen communicate regarding the ’405 Patent |
| 2017-12-15 | Complaint Filed |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 9,375,405 - "Rapid Dissolution Formulation of a Calcium Receptor-Active Compound"
- 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 states that certain calcium receptor-active compounds, such as cinacalcet hydrochloride (HCl), are "insoluble or sparingly soluble in water," which can limit formulation options and result in "low bioavailability" of the drug when administered to a patient ('405 Patent, col. 6:10-21).
- The Patented Solution: The invention is a pharmaceutical composition that maximizes the dissolution of the drug by combining cinacalcet HCl with a specific combination of excipients—including diluents, binders, and disintegrants—within defined weight percentage ranges ('405 Patent, Abstract; col. 8:57-9:12). This formulation is designed to achieve a "defined dissolution profile" where a significant portion of the drug is released within 30 minutes in a simulated stomach-acid environment, thereby improving its potential for absorption in the body ('405 Patent, col. 6:29-32, 6:40-51).
- Technical Importance: For poorly soluble drugs, achieving rapid dissolution in the gastrointestinal tract is a critical factor in ensuring that a sufficient amount of the active ingredient is absorbed into the bloodstream to produce a therapeutic effect ('405 Patent, col. 6:18-24).
Key Claims at a Glance
- The complaint asserts at least independent claim 1 ('405 Patent, col. 13:16-39; Compl. ¶40).
- Claim 1 requires a pharmaceutical composition comprising:
- (a) from about 10% to about 40% by weight of cinacalcet HCl;
- (b) from about 45% to about 85% by weight of a specific diluent;
- (c) from about 1% to about 5% by weight of a specific binder; and
- (d) from about 1% to about 10% by weight of a specific disintegrant;
- wherein the composition is for treating hyperparathyroidism or related conditions.
- The complaint does not explicitly reserve the right to assert other claims, but its allegation of infringement of "at least claim 1" suggests this possibility (Compl. ¶40).
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 marketing approval is sought under ANDA No. 202416 (Compl. ¶5).
Functionality and Market Context
- The accused ANDA products are intended to be generic versions of Amgen's branded drug, SENSIPAR® (Compl. ¶24). They are designed to be therapeutically equivalent and used for the same indications: treating secondary hyperparathyroidism in patients with chronic kidney disease on dialysis and hypercalcemia in patients with parathyroid carcinoma (Compl. ¶17-19). The act of infringement alleged is the submission of the ANDA itself, which seeks FDA approval to market these products before the expiration of the ’405 Patent (Compl. ¶39). No probative visual evidence provided in complaint.
IV. Analysis of Infringement Allegations
The complaint alleges that the Defendants' ANDA products will infringe at least claim 1, but does not provide a detailed element-by-element breakdown or claim chart exhibit. The infringement theory is based on the composition of the proposed generic product as described in ANDA No. 202416.
’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 composition described in ANDA No. 202416 allegedly contains cinacalcet HCl within the claimed percentage and dosage amounts. | ¶40 | col. 7:16-24 |
| (b) from about 45% to about 85% by weight of a diluent selected from the group consisting of microcrystalline cellulose, starch, dicalcium phosphate, lactose, sorbitol, mannitol, sucrose, methyl dextrins, and mixtures thereof, | The composition described in ANDA No. 202416 allegedly contains a diluent from the specified group within the claimed percentage range. | ¶40 | col. 8:58-60 |
| (c) from about 1% to about 5% by weight of at least one binder selected from the group consisting of povidone, hydroxypropyl methylcellulose, hydroxypropyl cellulose, sodium carboxymethylcellulose, and mixtures thereof; and | The composition described in ANDA No. 202416 allegedly contains a binder from the specified group within the claimed percentage range. | ¶40 | col. 8:60-63 |
| (d) from about 1% to 10% by weight of at least one disintegrant selected from the group consisting of crospovidone, sodium starch glycolate, croscarmellose sodium, and mixtures thereof, | The composition described in ANDA No. 202416 allegedly contains a disintegrant from the specified group within the claimed percentage range. | ¶40 | col. 8:63-65 |
| wherein the composition is for the treatment of at least one of hyperparathyroidism, hyperphosphonia, hypercalcemia, and elevated calcium phosphorus product. | The proposed labeling for the ANDA product will direct its use for the treatment of these conditions. | ¶46 | col. 7:17-20 |
- Identified Points of Contention:
- Technical Questions: A central question, unanswerable from the complaint alone, is whether the precise formulation disclosed in the confidential ANDA falls within the specific weight-percentage ranges for each category of excipient (diluent, binder, disintegrant) required by claim 1.
- Scope Questions: The analysis may raise the question of whether an excipient in the accused product serves multiple functions (e.g., acts as both a diluent and a disintegrant). How such an excipient is categorized could determine whether the formulation meets the percentage limitations for different elements of the claim.
V. Key Claim Terms for Construction
The complaint does not provide sufficient detail for analysis of specific disputed terms. However, based on the technology and typical formulation disputes, the following terms may become central to the case.
The Term: "about"
Context and Importance: This term precedes every numerical range in claim 1 (e.g., "about 10% to about 40%"). Its interpretation is critical because infringement will depend on whether the precise percentages of ingredients in Defendants' formulation, as specified in their ANDA, fall within the claimed ranges. Practitioners may focus on this term because even a small deviation in the accused formulation from a recited number could be dispositive of infringement, making the scope of "about" a key battleground.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The patent does not provide an explicit definition. A party might argue the term should be interpreted by considering the "purpose of the invention," which is to achieve a specific rapid dissolution profile ('405 Patent, col. 8:13-21). The variability shown in the example formulations for different tablet strengths may also be cited to support a degree of flexibility in the numbers ('405 Patent, col. 11, Table).
- Evidence for a Narrower Interpretation: A party could argue the term should be limited by the number of significant digits used in the claims and examples, suggesting it covers only minor variations attributable to standard manufacturing tolerances. The fact that the patent provides specific, multi-digit weight percentages in its examples could be used to argue against an overly broad interpretation ('405 Patent, col. 11, Table).
The Term: "diluent"
Context and Importance: Claim 1 requires a large proportion of the composition ("from about 45% to about 85%") to be a "diluent" from a specific list. Some listed substances, like starch, can also function as disintegrants or binders. The classification of excipients in the accused product will be crucial. If Defendants use an excipient that Amgen considers a "diluent" but Defendants classify as something else, it could move the formulation outside the claimed range.
Intrinsic Evidence for Interpretation:
- Evidence for a Broader Interpretation: The claim lists diluents that are "selected from the group consisting of..." which defines a closed Markush group ('405 Patent, col. 13:22-25). However, the specification states the composition can be chosen from "diluents such as starch, microcrystalline cellulose..." ('405 Patent, col. 8:58-60). The use of "such as" in the specification could be argued to provide context for the function of a diluent.
- Evidence for a Narrower Interpretation: A party would argue the term is strictly limited to the explicit list provided in the claim text itself. Any functional overlap with other categories (e.g., disintegrant) would be used to argue that the weight of that excipient should not be counted, or should be apportioned, for the purposes of the "diluent" limitation.
VI. Other Allegations
Indirect Infringement
- The complaint alleges that upon FDA approval, Defendants' manufacture, use, and sale of their ANDA products will induce and/or contribute to the infringement of at least claim 1 (Compl. ¶46). The basis for this allegation is the intent to market the product immediately upon approval and the substantial preparations already made (Compl. ¶43-44). The product's future label would presumably instruct users to take the drug in an infringing manner.
Willful Infringement
- The complaint does not use the term "willful infringement" but lays a factual predicate for such a claim. It alleges Defendants had knowledge of the ’405 patent through multiple channels: its listing in the FDA Orange Book as of July 2016 (Compl. ¶31), a separate lawsuit filed by Amgen against Defendants in September 2016 asserting the patent against a different ANDA (Compl. ¶32), and direct communication between the parties' counsel in September 2017 (Compl. ¶33). The prayer for relief requests a declaration that the case is "exceptional" under 35 U.S.C. § 285, which is consistent with an assertion of willful conduct (Compl. Prayer ¶D).
VII. Analyst’s Conclusion: Key Questions for the Case
The resolution of this case will likely depend on the answers to the following questions, which are unanswerable from the complaint alone:
- A central evidentiary question will be one of compositional identity: Does the specific formulation of excipients and their precise weight percentages, as confidentially disclosed in Defendants’ ANDA No. 202416, literally fall within the numerical ranges required by each element of claim 1 of the ’405 patent?
- The case may also turn on a question of claim construction: How should the term "about" be defined? Will its scope be broad enough to capture Defendants' formulation if it lies near, but not strictly within, the recited numerical boundaries?
- A related legal and factual question will be one of component classification: If the accused formulation contains excipients with multiple pharmaceutical functions (e.g., a compound that can act as both a diluent and a disintegrant), how will that component be classified for the purpose of satisfying the distinct percentage limitations of the patent claims?