DCT
1:14-cv-00915
Merck Sharp & Dohme Corp v. Hospira Inc
Key Events
Complaint
I. Executive Summary and Procedural Information
- Parties & Counsel:
- Plaintiff: Merck Sharp & Dohme Corp. (New Jersey)
- Defendant: Hospira, Inc. (Delaware)
- Plaintiff’s Counsel: Morris, Nichols, Arsht & Tunnell LLP
- Case Identification: Merck Sharp & Dohme Corp v. Hospira Inc, 1:14-cv-00915, D. Del., 07/11/2014
- Venue Allegations: Venue is alleged to be proper in the District of Delaware because Defendant Hospira, Inc. is a Delaware corporation.
- Core Dispute: Plaintiff alleges that Defendant's submission of an Abbreviated New Drug Application (ANDA) to the FDA for a generic version of the antibiotic Invanz® constitutes an act of infringement of a patent covering stabilized formulations of the active ingredient, ertapenem.
- Technical Context: The technology concerns pharmaceutical chemistry, specifically methods for stabilizing carbapenem-class antibiotics, which are prone to degradation, to create a viable product for injection.
- Key Procedural History: This action was initiated under the Hatch-Waxman Act. Plaintiff Merck is the holder of an approved New Drug Application (NDA) for its ertapenem product, Invanz®, and has listed the patent-in-suit in the FDA's "Orange Book." Defendant Hospira filed an ANDA seeking to market a generic version, including a "Paragraph IV Certification" asserting that the patent-in-suit is invalid. This lawsuit was filed within the 45-day window following Merck's receipt of Hospira's notice letter, triggering a statutory 30-month stay on FDA approval of Hospira's ANDA.
Case Timeline
| Date | Event |
|---|---|
| 1996-05-28 | Earliest Priority Date for U.S. Patent No. 5,952,323 |
| 1999-09-14 | U.S. Patent No. 5,952,323 Issued |
| 2014-05-29 | Date of Hospira's Notice Letter to Merck |
| 2014-05-30 | Merck Receives Hospira's Notice Letter |
| 2014-07-11 | Complaint Filing Date |
II. Technology and Patent(s)-in-Suit Analysis
U.S. Patent No. 5,952,323 - "CARBAPENEM ANTIBIOTIC" (issued Sep. 14, 1999)
The Invention Explained
- Problem Addressed: The patent addresses the need for stable pharmaceutical compositions of a specific carbapenem antibiotic, referred to as "compound of formula I" (ertapenem) ('323 Patent, col. 1:8-10). The specification notes that the native pH of the monosodium salt of this compound is approximately 5.4, implying a need for a formulation that achieves a different pH to ensure stability for administration ('323 Patent, col. 2:42-43).
- The Patented Solution: The invention claims to solve this problem by combining the ertapenem compound with a "carbon dioxide source," such as sodium bicarbonate or sodium carbonate ('323 Patent, col. 2:21-26, 39-42). This combination is described as forming a "stabilized form" of the antibiotic, designated as "formula II," which features a carbamate group formed at a specific nitrogen atom in the molecule ('323 Patent, col. 2:36-39). This formulation is designed to achieve a pH between 6.0 and 9.0 upon dissolution, which extends the product's stability in solution ('323 Patent, col. 2:15-20; col. 3:25-37).
- Technical Importance: This stabilization technology provides a method to formulate the otherwise less stable ertapenem antibiotic into a product suitable for intravenous and intramuscular administration ('323 Patent, col. 1:12-15).
Key Claims at a Glance
- The complaint alleges infringement of at least method claim 4 and of claims covering the stabilized product itself (Compl. ¶16-17). The primary independent claims implicated are Claim 1 (product) and Claim 4 (method).
- Independent Claim 1:
- A compound represented by the formula II.
- or a pharmaceutically acceptable salt, prodrug or hydrate thereof.
- Independent Claim 4:
- A method of stabilizing a carbapenem of the formula I...
- comprising adding to the compound a sufficient amount of a carbon dioxide source...
- to form a compound of formula II... or a pharmaceutically acceptable salt, prodrug or hydrate thereof.
- The complaint does not explicitly reserve the right to assert dependent claims.
III. The Accused Instrumentality
- Product Identification: The accused instrumentality is Hospira's generic drug product, identified as "ertapenem for injection 1g," for which Hospira submitted ANDA No. 206480 to the FDA (Compl. ¶10).
- Functionality and Market Context: The Hospira product is intended to be a generic equivalent of Merck's branded antibacterial drug, Invanz® (Compl. ¶7, ¶10). The complaint alleges that Hospira has represented to the FDA that its product is "pharmaceutically and therapeutically equivalent" to Invanz® (Compl. ¶28). The core of the infringement allegation is that this generic product "contains the stabilized form of ertapenem described and claimed in the '323 patent" and that its manufacture "requires the performance of every step of at least method claim 4" of the patent ('323 Patent, Compl. ¶16-17, ¶29-30).
IV. Analysis of Infringement Allegations
The complaint provides a high-level infringement theory without a detailed claim chart. The allegations are summarized below.
5,952,323 Infringement Allegations (Claim 1)
| Claim Element (from Independent Claim 1) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A compound represented by the formula II... or a pharmaceutically acceptable salt, prodrug or hydrate thereof. | The complaint alleges on information and belief that the Hospira Generic Product contains the "stabilized form of ertapenem described and claimed in the '323 patent," which corresponds to the structure of formula II. | ¶16, ¶29 | col. 9:1-9 |
5,952,323 Infringement Allegations (Claim 4)
| Claim Element (from Independent Claim 4) | Alleged Infringing Functionality | Complaint Citation | Patent Citation |
|---|---|---|---|
| A method of stabilizing a carbapenem of the formula I... | The complaint alleges that the manufacture of the Hospira Generic Product requires performing the claimed stabilization method. | ¶17, ¶30 | col. 9:40-42 |
| comprising adding to the compound a sufficient amount of a carbon dioxide source | The complaint alleges that Hospira's manufacturing process performs "every step" of claim 4, which includes this step. | ¶17, ¶30 | col. 9:44-45 |
| to form a compound of formula II... | The complaint alleges that Hospira's process results in the claimed stabilized form of ertapenem. | ¶16, ¶17 | col. 9:45-47 |
- Identified Points of Contention:
- Technical Questions: A primary factual dispute will likely be whether Hospira's formulation, as specified in its confidential ANDA, actually contains the specific chemical entity of formula II. The case may turn on analytical evidence (e.g., spectroscopy) capable of detecting the presence or absence of the claimed carbamate group in Hospira's final product.
- Scope Questions: The infringement analysis for method claim 4 will raise the question of whether Hospira's manufacturing process uses "a sufficient amount of a carbon dioxide source" for the claimed purpose of "form[ing] a compound of formula II." If Hospira's process uses a different stabilizer, or uses a CO2 source in an amount or manner that does not result in the formation of the formula II compound, infringement may be contested.
No probative visual evidence provided in complaint.
V. Key Claim Terms for Construction
- The Term: "stabilized form"
- Context and Importance: This term is foundational to the product claims. The outcome of the case may depend on whether Hospira's product is considered a "stabilized form" as that term is used in the patent. Practitioners may focus on this term as it directly links the patent's contribution to the accused product.
- Intrinsic Evidence for Interpretation:
- Evidence for a Narrower Interpretation: The patent provides an explicit definition: "As used herein, the term 'stabilized form' refers to compounds which have a carbamate group formed at the pyrrolidine nitrogen atom, as shown in compounds of formula II" ('323 Patent, col. 2:36-39). This definition appears to tie the term directly to a specific chemical structure.
- Evidence for a Broader Interpretation: A party might argue that the term should be understood more functionally, encompassing any form stabilized by the disclosed method, but the patent's express definition presents a significant hurdle to such an argument.
- The Term: "a sufficient amount"
- Context and Importance: This term in method claim 4 is critical for determining whether Hospira's manufacturing process infringes. The quantity of the "carbon dioxide source" is a key process parameter that will be specified in the ANDA.
- Intrinsic Evidence for Interpretation:
- Evidence for a Narrower Interpretation: The claim itself provides a functional limit: the amount must be sufficient "to form a compound of formula II" ('323 Patent, col. 9:45-47). Further, the specification provides examples of formulations by weight ratio (e.g., "about 4.5 parts by weight, of compound I... and 1 part by weight of sodium bicarbonate") and the resulting pH (e.g., "approximately 6.5"), which could be used to argue for a specific, functional range required to meet the claim limitation ('323 Patent, col. 3:20-25).
- Evidence for a Broader Interpretation: A party could argue that any amount that initiates the formation of any detectable quantity of the formula II compound is "sufficient," even if it is a minor component in an equilibrium mixture.
VI. Other Allegations
- Indirect Infringement: The complaint includes allegations of active inducement and contributory infringement under 35 U.S.C. §271(b) and (c), based on the anticipated "commercial manufacture, use, or sale of the Hospira Generic Product" post-FDA approval (Compl. ¶18, ¶31). The factual basis for these allegations is not detailed beyond the act of seeking approval for a product alleged to infringe.
- Willful Infringement: The complaint alleges that Hospira was "aware of the existence of the '323 patent" and that its ANDA filing constituted an act of infringement (Compl. ¶15). It seeks a finding that the case is "exceptional" and an award of attorney fees under 35 U.S.C. §285 (Compl. ¶21, ¶33(e)). The basis for pre-suit knowledge is Hospira's statutory obligation to address Orange Book-listed patents in its ANDA submission.
VII. Analyst’s Conclusion: Key Questions for the Case
- A core issue will be one of chemical identity: does Hospira's proposed generic product, as defined in its ANDA, contain the specific chemical structure of "formula II" as claimed in the '323 patent, or does it achieve the required stability through a different formulation that avoids forming the patented carbamate adduct?
- A key evidentiary question will be one of process infringement: does the manufacturing process detailed in Hospira's ANDA utilize "a sufficient amount of a carbon dioxide source" for the express purpose and with the result of forming the claimed "stabilized form," as required by method claim 4?
- The case will also centrally involve Hospira's validity challenge. While the complaint focuses on infringement, the ultimate disposition will depend on whether Hospira can prove by clear and convincing evidence that the asserted claims of the '323 patent are invalid, the very assertion it made in its Paragraph IV certification to the FDA (Compl. ¶11, ¶27).