Senju Pharm. Co. v. Apotex Inc.
| Decision Date | 20 December 2011 |
| Docket Number | Civ. No. 07–779–SLR. |
| Court | U.S. District Court — District of Delaware |
| Parties | SENJU PHARMACEUTICAL CO. LTD., Kyorin Pharmaceutical Co. Ltd. and Allergan, Inc., Plaintiffs, v. APOTEX INC. and Apotex Corp., Defendants. |
OPINION TEXT STARTS HERE
Jack B. Blumenfeld, Esq. and Maryellen Noreika, Esq. of Morris, Nichols, Arsht & Tunnell LLP, Wilmington, DE, of Counsel, Richard D. Kelly, Esq., Stephen G. Baxter, Esq. and Frank J. West, Esq. of Obion, Spivak, McClelland, Maier & Neustadt, P.C., for Plaintiffs.
Francis J. Murphy, Esq. of Murphy & Landon, Wilmington, DE, of Counsel, David G. Greene, Esq. and Alan B. Clement of Locke Lord Bissell & Liddell LLP; Keith D. Parr, Esq., Scott B. Feder, Esq., David B. Abramowitz, Esq., Patrick C. Gallagher, Esq. and Kevin M. Nelson, Esq. of Locke Lord Bissell & Liddell LLP, for Defendants.
I. INTRODUCTION
Senju Pharmaceutical Co., Ltd. (“Senju”) and Kyorin Pharmaceutical Co., Ltd. (“Kyorin”) are co-owners of U.S. Patent No. 6,333,045 (“the '045 patent”). (D.I. 100, ex. 1 at ¶ 7) The '045 patent is directed to aqueous liquid pharmaceutical compositions comprising gatifloxacin and disodium edetate, as well as various methods utilizing these compositions. ('045 patent at col. 1:7–57) Allergan, Inc. (“Allergan”) holds a New Drug Application (“the NDA”),1 approved by the United States Food and Drug Administration (“FDA”), which describes a 0.3% gatifloxacin ophthalmic solution, sold under the trade name ZYMAR®. (D.I. 100, ex. 1 at ¶¶ 9–10) ZYMAR® is indicated for the treatment of bacterial conjunctivitis. ( Id.) The FDA's Approved Drug Products With Therapeutic Equivalence Evaluations (“the Orange Book”) lists, inter alia, the ' 045 patent and U.S. Patent No. 4,980,470 (“the '470 patent”)2 in connection with ZYMAR®. ( Id. at ¶¶ 12, 21)
On July 18, 2007, Apotex Inc. filed an Abbreviated New Drug Application (“the ANDA”) 3 with the FDA, seeking approval, prior to the expiry of the ' 045 patent, to manufacture, market and sell a generic version of the 0.3% gatifloxacin ophthalmic solution described in the NDA (“the ANDA product”). ( Id. at ¶ 13) Apotex Inc. subsequently assigned its rights in the ANDA to Apotex Corp. (collectively, “Apotex” or “defendants”). ( Id. at ¶ 16) On October 17, 2007, defendants sent Senju, Kyorin and Allergan (collectively, “plaintiffs”) a letter informing plaintiffs that the ANDA contained a Paragraph IV certification 4 for the ' 045 patent. ( Id. at ¶ 17) Therein, defendants asserted that the ANDA product would not infringe claims 4, 5, 10 and 11 of the ' 045 patent and that all the claims of the ' 045 patent were invalid. ( Id. at ¶ 18)
Plaintiffs brought an infringement action on November 29, 2007 pursuant to 35 U.S.C. § 271(e)(2)(A), alleging that the ANDA product would infringe claims 1–3, 6, 7 and 9 of the '045 patent. (D.I. 1 at ¶¶ 32, 33) Defendants responded with affirmative defenses and counterclaims seeking declaratory judgment of noninfringement, invalidity and unenforceability of the '045 patent. (D.I. 63) While defendants maintained that claims 6 and 7 would not be infringed, the parties stipulated that, if valid, the ANDA product would infringe claims 1–3 and 9 of the '045 patent. (D.I. 100, ex. 2 at 1) The court held a claim construction hearing on December 4, 2009. A bench trial was conducted on January 12–14, 2010.
Thereafter, the court made the following findings of fact and conclusions of law pursuant to Fed.R.Civ.P. 52(a): (1) defendants' ANDA product infringed claims 1–3, 6, 7, and 9 of the '045 patent; (2) defendants demonstrated that claims 1–3 and 6–9 of the '045 patent are rendered obvious by prior art; (3) defendants failed to demonstrate that claims 6 and 7 of the '045 patent are invalid for lack of enablement and; (4) defendants failed to demonstrate inequitable conduct. (D.I. 123)
Plaintiffs motioned for a new trial or, alternatively, to amend judgment and findings regarding claim 7. (D.I. 126) Plaintiffs asserted that defendants relied on evidence which was outside of defendants' expert report on obviousness and that this evidence was not properly disclosed or vetted during discovery. ( Id.) Specifically, plaintiffs argued that defendants cited, and the court relied upon, disclosures from a 1989 article by Riley et al. (“the Riley reference”), to show a link between solubility and precipitation. ( Id. at 5) Plaintiffs contend that information from this article, used in the trial, was outside of Dr. Myrdal's expert report. 5( Id.) On November 3, 2010, 2010 WL 4538265, the record was reopened regarding claim 7. (D.I. 129) An evidentiary hearing was held on April 27 and May 4, 2011 to allow for further evidence on the relationship between precipitation and solubility, as detailed infra. (D.I. 139)
II. SUPPLEMENTAL FINDINGS OF FACT AND CONCLUSIONS OF LAWA. The Parties
1. Senju is a Japanese corporation with its principal place of business in Osaka, Japan. (D.I. 100, ex. 1 at ¶ 1) Senju develops pharmaceutical products that have applications regarding the eye, ear, nose, throat and skin. (D.I. 122, 717 F.Supp.2d at 409) Kyorin is a Japanese corporation with its principal place of business in Tokyo, Japan. (D.I. 100, ex. 1 at ¶ 2) Kyorin engages in the development of pharmaceuticals directed to infectious, immunological, allergic and metabolic diseases. (D.I. 122, 717 F.Supp.2d at 409) Allergan is a corporation formed under the laws of the State of Delaware, having its principal place of business in Irvine, California. (D.I. 100, ex. 1 at ¶ 3) Allergan develops and sells pharmaceuticals, biologies and medical devices. (D.I. 122, 717 F.Supp.2d at 409)
2. Apotex Corp. is a corporation formed under the laws of the State of Delaware, having its principal place of business in Weston, Florida. (D.I. 100, ex. 1 at ¶ 4) Apotex Corp. offers for sale and sells numerous generic drugs manufactured and supplied by Apotex Inc., a corporation formed under the laws of Canada, having its principal place of business in Ontario, Canada. (D.I. 13 at ¶ 6; D.I. 100, ex. 1 at ¶ 5) Apotex Inc. primarily develops, manufactures and commercializes generic pharmaceutical products. (D.I. 13 at ¶ 8)
B. Technology at Issue
3. Fluoroquinolones, otherwise known as quinolone carboxylic acids or simply “quinolones,” are a class of broad spectrum antibacterial compounds that share a common core chemical structure. (D.I. 107 at 326:19–20; '470 patent at col. 1:7–13) A carboxylic acid, along with a nitrogen-containing carbon ring and a double-bonded oxygen, are fundamental and common aspects of all quinolone antibiotics. ('470 patent at col. 2:12–25)
4. The '470 patent was before the examiner during the prosecution of the ' 045 patent and claims gatifloxacin 6 and its acid derivatives. ( Id. at col. 1:1–8) The properties of gatifloxacin, a fourth generation quinolone, are revealed following a discussion of previously discovered quinolones, to wit, norfloxacin, ofloxacin and ciprofloxacin. ( Id. at col. 1:32–61) The ' 470 patent explains that each of the disclosed quinolones have “similar substituents.” ( Id. at col. 1:41–43)
5. On December 25, 2001, the '045 patent, entitled “Aqueous Liquid Pharmaceutical Composition Comprised of Gatifloxacin,” was issued listing Shinichi Yasueda and Katsuhiro Inada (“Mr. Inada”) as inventors. (D.I. 100, ex. 1 at ¶ 6) The '045 patent discloses gatifloxacin as a new quinolone with antimicrobial activity. ('045 patent at col. 1:19–20) The object of the '045 patent was to invent an aqueous liquid pharmaceutical composition comprising gatifloxacin for topical administration, applicable in the ophthalmological or otorhinological field. ( Id. at col. 1:40–50) The '045 patent's summary discloses improved solubility of gatifloxacin at physiological pH due to the coexistence of disodium edetate. ( Id. at col. 2:13–14)
6. At issue in this case is claim 7 of the '045 patent, which describes a method for preventing the precipitation of gatifloxacin crystals and comprises the incorporation of disodium edetate into an aqueous liquid preparation containing gatifloxacin or its salt. ( Id. at col. 8:42–45)
a. Primary references
7. At trial, Dr. Myrdal testified that, in the context of quinolone solution chemistry, variations in functional groups among the quinolones named by the ' 470 patent are “really not from a physical/chemical standpoint huge differences.” (D.I. 107 at 327:1–2) Generally, while different functional groups may result in some differences in solubility, one of skill in the art can expect a relatively predictable pH-dependent solubility profile for these quinolones. ( Id. at 351:12–15)
8. Dr. Myrdal relied on the Riley reference, which proposed several simulated solubility profiles for quinolones.7 (D.I. 108 at 665:13–15) The Riley reference demonstrates that quinolones with similar pka8 values exhibit a U-shaped solubility curve with an inflection point around each of the pka values. (JTX–015 at 32–34) A further teaching of the Riley reference describes how the addition of carboxylic acids, of various sizes and structures, to a quinolone solution maintained at pH of 5 resulted in the increased solubility of the quinolone. ( Id.)
9. Disodium edetate (commonly known as “EDTA”) has four carboxylic acid groups. (D.I. 107 at 354:9–10; D.I. 108 at 669:15–16) EDTA is the disodium salt of ethylenediamine tetraacetic acid.9 (D.I. 100, ex. 1 at ¶ 40) EDTA, a multi-purpose excipient,10 is widely known as a chelating agent.11 (D.I. 107 at 332:10; DTX–166 at 109)
10. U.S. Patent No. 4,551,456 (“the '456 patent”), teaches that quinolones 12are “compatible with ocular tissue” and useful in treating bacterial ocular infections through topical administration. (' 456 patent at col. 1:13–31) The ' 456 patent discloses EDTA in a list of 8 excipients described as “conventional ingredients” in ophthalmic compositions. ( Id. at col. 2:5–9) One of two exemplary...
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...tetraacetic acid. EDTA, a multi-purpose excipient, is widely known as a chelating agent." Senju Pharmaceutical Co. Ltd. v. Apotex Inc., 836 F.Supp. 2d 196, 200 (D. Del. 2011). Stallworth testified at trial that police planted the blood found on his jacket. Counsel pleaded in Stallworth's po......
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