Imperial Chemical Industries v. Danbury Pharmacal, Inc., Civ. A. No. 89-575-CMW

• Decision Date: 04 November 1991
• Docket Number: Civ. A. No. 89-575-CMW,90-736-CMW.
• Parties: IMPERIAL CHEMICAL INDUSTRIES, PLC, Plaintiff, v. DANBURY PHARMACAL, INC., Defendant.
• Court: U.S. District Court — District of Delaware

777 F. Supp. 330

IMPERIAL CHEMICAL INDUSTRIES, PLC, Plaintiff, v. DANBURY PHARMACAL, INC., Defendant.

Civ. A. Nos. 89-575-CMW, 90-736-CMW.

United States District Court, D. Delaware.

November 4, 1991.

COPYRIGHT MATERIAL OMITTED

Douglas E. Whitney, Donald F. Parsons, Jr., and Jack B. Blumenfeld of Morris, Nichols, Arsht & Tunnell, Wilmington, Del. (Donald J. Bird, Stephen L. Sulzer, Lynn E. Eccleston, and Mark G. Paulson of Cushman, Darby & Cushman, Washington, D.C., of counsel), for plaintiff.

Jeffrey M. Weiner, Wilmington, Del. (Alfred B. Engelberg, Greenwich, Conn., of counsel), for defendant.

OPINION

CALEB M. WRIGHT, Senior District Judge.

The plaintiff-patentee Imperial Chemical Industries, PLC ("ICI"), is a British corporation having its corporate offices and principal place of business in Imperial Chemical House, Millbank, London, England. Consolidated Pretrial Order ("P.T. Order") filed March 6, 1991 at p. III-1. The defendant Danbury Pharmacal, Inc., ("Danbury"), is a corporation organized and existing under the laws of the State of Delaware having its principal place of business at Stoneleigh Avenue, Carmel, New York. Id. ICI has charged Danbury with infringement of ICI's U.S. Patent No. 3,934,032, ("the '032 patent") and Danbury has asserted the invalidity of this patent as an affirmative defense in Civil Action Nos. 89-575 and 90-736.¹ P.T. Order at p. I-1. The subject '032 patent was issued to ICI on January 20, 1976 with two claims directed to a method for the treatment of hypertension in a warm-blooded animal by the administration of a particular alkanolamine derivative.² The preferred compound covered by the '032 patent is generically known as "atenolol". P.T. Order at p. I-3.

On June 30, 1989, Danbury filed two abbreviated new drug applications ("ANDAs") Nos. 73-352 and 73-353. The two ANDAs which are the subject of Civil Action No. 89-575, seek authorization from the U.S. Food and Drug Administration ("FDA") to sell a generic version of the drug atenolol in 50 mg and 100 mg tablets, respectively, after the expiration date of the '032 patent. P.T. Order at p. I-2. Atenolol is marketed for the treatment of hypertension by ICI under the trademark TENORMIN. P.T. Order at p. I-3. On September 5, 1989, Danbury amended ANDAs Nos. 73-352 and 73-353 and simultaneously submitted a patent certification which alleged, pursuant to 21 U.S.C. § 355(j)(2)(A)(vii) (1988), that the '032 patent and ICI's U.S. Patent No. 3,836,671 ("the '671 patent")³ were invalid. Further, Danbury sought approval to market atenolol immediately, without regard to the expiration date of the '032 and '671 patents. P.T. Order at p. I-2.

On November 5, 1990, Danbury filed an ANDA (number unspecified) which is the subject of Civil Action No. 90-736, seeking authorization from the FDA to sell a generic version of the drug atenolol/chlorthalidone. P.T. Order at p. I-2. Atenolol in combination with chlorthalidone is marketed for the treatment of hypertension by ICI under the trademark TENORETIC. P.T. Order at p. I-3. Concurrent with the filing of this ANDA, Danbury submitted a patent certification which alleged, pursuant to 21 U.S.C. § 355(j)(2)(A)(vii) (1988), that the '032 patent was invalid, and that Danbury sought approval to market the combined drug atenolol/chlorthalidone commencing September 17, 1991 (after the expiration of the '671 patent) without regard to the expiration date of the '032 patent. P.T. Order at pp. I-2, 3.

Danbury's submission of the ANDAs and the patent certification challenging the validity of the '032 patent, constitutes infringement of the '032 patent under 35 U.S.C. § 271(e)(2)(A) (1988). Danbury has admitted infringement with respect to both atenolol per se and atenolol/chlorthalidone combinations, and raised the affirmative defense of invalidity. FDA approval of Danbury's ANDAs could have been effective immediately (assuming the ANDAs are otherwise in compliance with FDA requirements) except that ICI brought suit within forty-five days of its receipt of the patent certification notices.⁴ P.T. Order at pp. I-3, 4. Since ICI filed suit within the forty-five day period,⁵ the FDA may not permit Danbury to market its generic drug for a period of thirty months from the date of the receipt of the patent certification notices⁶ unless both claims of the '032 patent are finally adjudicated to be invalid before the respective thirty month periods expire.⁷ P.T. Order at p. I-4.

This Court has jurisdiction under the United States Patent Laws, Title 35, and under 28 U.S.C. §§ 1331, 1338(a). In addition, this action is authorized under the Food and Drug Law, Title 21, and specifically 21 U.S.C. § 355(j)(4)(B) (1988). Venue is found under 28 U.S.C. § 1400(b) since the defendant Danbury is a Delaware corporation.⁸ P.T. Order at p. II-1.

The Court held an eight day bench trial from April 1 through April 5 and April 8 through April 10, 1991. Since Danbury has admitted infringement of the '032 patent and has not engaged in any commercial activity relating to the '032 patent the sole issues for determination at trial were the validity and enforceability of claim 2 of the '032 patent. After trial, the parties submitted proposed findings of fact and conclusions of law. The Court has considered the parties' post-trial submissions along with the testimony and documentary evidence presented at trial. After this review the Court renders this Opinion containing its Findings of Fact and Conclusions of Law pursuant to Rule 52(a) of the Federal Rules of Civil Procedure.

Danbury seeks a declaration that claim 2 of the '032 patent is invalid and grounds its attack on validity upon 35 U.S.C. § 103 (1988) ("section 103")⁹ and 35 U.S.C. § 112 (1988) ("section 112")¹⁰. The basis of Danbury's § 103 defense of obviousness is that "given the scope and content of the prior art, the nature of the differences between atenolol and the prior art and level of skill in the art, a medicinal chemist of ordinary skill in the art in February, 1969 would reasonably have expected that atenolol because of its R-ABC structure and the close similarity of its R group to known R groups would also be a beta-blocker and, therefore, be useful as an antihypertensive agent." Defendant Danbury's Proposed Findings of Fact and Conclusions of Law ("DFC") at p. 32, ¶ 50.

The basis for Danbury's § 112 defense is "the patent specification's alleged failure to disclose adequately to one of ordinary skill in the art `how to use' the invention without undo experimentation." DFC at p. 71, ¶ 86. It is Danbury's position that "the '032 patent in suit does not disclose, and would not teach, a person of ordinary skill in the art how to use atenolol to treat hypertension in the manner ultimately approved by the FDA¹¹ and that extensive experimentation with atenolol over a period of many years was required by those skilled in the art before they ultimately learned of the possibility of using atenolol to treat hypertension at a dose as low as 100 mg. taken once-a-day." DFC at p. 28, ¶ 44.

ICI counters that "in light of the significant structural differences between atenolol and the prior art, the lack of any teachings in the prior art which would have suggested the modifications required to make atenolol, atenolol's unexpected, qualitatively different combination of pharmacological properties, and its advantages over the prior art in the treatment of hypertension, and the other objective evidence of nonobviousness (i.e., the invention's outstanding commercial success, the pharmaceutical industry's acquiescence in the '032 patent's validity, and Danbury's copying of atenolol), the invention of claim 2 of the '032 patent would not have been obvious to one of ordinary skill in the art when the invention was made on February 21, 1969." Plaintiff ICI's Findings of Fact and Conclusions of Law ("PFC") at pp. 238-39, ¶ 97.

ICI argues in opposition to Danbury's § 112 defense, that "the disclosure of the '032 patent specification would have enabled one skilled in the art, without undue experimentation, to practice the invention of claim 2 and to obtain atenolol's benefits of beta1-selectivity, lack of ISA, and hydrophilicity." PFC at p. 243, ¶ 107.

In the first part of this Opinion, "Findings of Fact", the following areas will be discussed: (a) The Patent In Suit; (b) The Scope and Content of the Prior Art;¹² (c) The Differences Between the Prior Art and the Claimed Invention; (d) The Development of the Patent in Suit; (e) The Level of Skill in the Art; (f) The Teachings of the '032 Patent; (g) Superior or Unexpected Results; (h) The Commercial Records of TENORMIN and TENORETIC. In the second part of this Opinion, "Conclusions of Law", the Court will address and state its conclusions of law in reference to the parties' legal theories and the pertinent case law regarding the following issues: (a) Burden of Proof; (b) Obviousness: 35 U.S.C. § 103; and (c) Adequate Disclosure: 35 U.S.C. § 112.

I. FINDINGS OF FACT

A. The Patent in Suit

The validity of claim 2 of U.S. Patent No. 3,934,032, entitled "Alkanolamine Derivatives for Treating Hypertension" is at issue in this case. This patent was issued to ICI on January 20, 1976 on application Serial No. 461,262 naming Arthur Michael Barrett, John Carter, Roy Hull, David James LeCount, and Christopher John Squire as inventors. Application Serial No. 461,262 was filed on April 15, 1974 as a division of Serial No. 233,781 filed March 10, 1972 (which is now U.S. Patent No. 3,836,671). Application Serial No. 233,781 was, in turn, a continuation-in-part of Application Serial No. 199,011 filed November 15, 1971 (now abandoned) and Application Serial No. 9451 filed February 6, 1970, which issued as U.S. Patent No. 3,633,607. P.T. Order at p. III-1.

Three separate patents were issued to ICI as a result of restriction requirements by the United States Patent and Trademark Office ("PTO") and double patenting is not an issue in this...