Barr Laboratories, Inc. (“Barr”), in December 1995, filed an Abbreviated New Drug Application (“ANDA”) under the Hatch-Waxman Act, see 21 U.S.C. § 355(j)(2)(A)(vii)(IV) (1994), seeking approval from the Food and Drug Administration (“FDA”) to market fluoxetine hydrochloride as an antidepressant. Flu-oxetine hydrochloride is the active ingredient in Eli Lilly and Company’s (“Lilly’s”) antidepressant drug Prozac. Lilly, on April 10, 1996, pursuant to 35 U.S.C. § 271(e)(2)(A) (1994), brought an in
Barr and the other defendants (collectively “Barr”)' argued, inter alia, that claim 5 of the ’081 patent and claim 7 of the ’549 patent are invalid for failure to comply with the best mode requirement and that claim 7 of the ’549 patent is invalid for double patenting. On cross-motions for summary judgment, the district court held in favor of Lilly, concluding that neither claim violates the best mode requirement and that no double patenting exists.
I. BACKGROUND
The present appeal concerns the validity of claim 5 of the ’081 patent that covers the pharmaceutical compound fluoxetine hydrochloride — the active ingredient in Lilly’s antidepressant drug Prozac — and claim 7 of the ’549 patent that covers the administration of fluoxetine hydrochloride to inhibit serotonin uptake in an animal’s brain neurons.
On January 10, 1974, Lilly filed application Serial No. 432,379 (“the ’379 application”) containing claims for a class of compounds, therapeutic methods of using those compounds, and pharmaceutical compositions comprising those compounds. The ’379 application named Bryan B. Mol-loy (“Molloy”) and Klaus K. Schmiegel as inventors. After its filing, the ’379 application engendered a progeny of divisional applications, continuation applications, and patents that rivals the Hapsburg legacy. When the last patent stemming from the ’379 application issued in December 1986, the application had spawned four divisional applications, three continuation applications, and six patents. During that twelve-year period, Lilly obtained six patents relating to fluoxetine hydrochloride— the ’081 and ’549 patents, as well as U.S. Patent Nos. 4,018,895 (“the ’895 patent”), 4,194,009 (“the ’009 patent”), 4,590,213 (“the ’213 patent”), and 4,329,356 (“the ’356 patent”). The ’213 and ’356 patents did not stem from the ’379 application, and during the course of this litigation, Lilly disclaimed those patents.
The ’009 patent, which expired in April 1994, claimed a class of pharmaceutical compounds, including fluoxetine hydrochloride, for administration in pyschotropically effective amounts. The ’895, ’213, and ’356 patents related to methods for treating particular ailments by administering a pharmaceutical compound within a class of compounds that includes fluoxetine hydrochloride. Specifically, the ’895 patent, which expired in April 1994, concerned the treatment of humans suffering from depression; the ’213 patent concerned the treatment of humans suffering from anxiety; and the ’356 patent concerned the treatment of animals suffering from hypertension.
In December 1995, pursuant to a Paragraph IV certification under the Hatch-Waxman Act, see 21 U.S.C.
At the district court, Barr argued that both claims are invalid for failure to comply with the best mode requirement and that claim 7 of the ’549 patent is invalid for obviousness-type double patenting. With regard to the issue of best mode, Barr advanced two independent arguments. First, Barr argued that the claims are invalid because the patents failed to disclose Molloy’s preferred method for synthesizing p-trifluoromethylphenol — a starting material necessary to make fluox-etine hydrochloride. Second, Barr argued that the claims are invalid because the patents failed to disclose Molloy’s preferred solvent for recrystallizing fluoxetine hydrochloride. With regard to the issue of double patenting, Barr advanced three independent arguments, contending that claim 7 of the ’549 patent is invalid in light of (1) the ’356 and ’213 patents, (2) the ’895 and ’009 patents, and (3) the ’081 patent.
On cross motions for summary judgment, the district court held in favor of Lilly, concluding that claim 5 of the ’081 patent and claim 7 of the ’549 patent do not violate the best mode requirement and that claim 7 is not invalid for double patenting under any of Barr’s theories. This appeal followed. Because these issues concern disparate parts of the record evidence, we describe separately the background relevant to each argument.
The Claims at Issue
A. Claim 5 of the ’081 patent
Stemming directly from the ’379 application, the ’081 patent issued on February 2, 1982. Claim 5 of the ’081 patent, which depends on claim 1, covers the compound N-methyl 3-(p-trifluoromethylphenoxy)-3-phenylpropylamine hydrochloride — commonly referred to as fluoxetine hydrochloride — and pharmaceutically-aceeptable acid addition salts thereof formed with non-toxic acids. Claim 1, in turn, provides as follows:
A compound of the formula
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wherein each R’ is independently H or CH3 and R is m- or p-chlorophenyl, o-, m-, or p-methoxyphenyl, phenyl, o- or m-fluorophenyl, o- or p-tolyl, 2,4-difluo-rophenyl or p-trifiuoromethylphenyl and acid addition salts formed with pharma-ceutically-acceptable acids.
On March 31, 1986, Lilly filed continuation application Serial No. 846,448, claiming the benefit of the 1974 filing date of the ’379 application under 35 U.S.C. § 120. On December 2, 1986, the application matured into the ’549 patent. Claim 7 of the ’549 patent, which depends on claim 4, relates to blocking the uptake of the mo-noamine serotonin in an animal’s brain neurons through administration of the compound N-methyl-3-(p-trifluoromethyl-phenoxy)-3-phenylpropylamine hydrochloride — commonly referred to as fluoxetine hydrochloride. Claim 4 provides as follows:
A method of blocking the uptake of mo-noamines by brain neurons in animals comprising administering to said animal a monoamine blocking amount of a compound of the formula
[[Image here]]
wherein each R’ is independently hydrogen or methyl; wherein R is naphthyl or
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wherein R” and R’” are halo, trifluoro-methyl, C4 -C4 alkyl, C4 -C3 alkyloxy or C3 —C4 alkenyl; and wherein n and m are 0, 1 or 2; and acid addition salts thereof formed with pharmaeeutically-acceptable acids.
C. Best Mode: p-trifluoromethylphenol
Both the ’081 and ’549 patents identify p-trifluoromethylphenol as a starting material for making fluoxetine hydrochloride. During the early stages of experimentation, Molloy used commercial p-trifluoro-methylphenol purchased from Marshallton Research Laboratories. However, when large quantities of p-trifluoromethylphenol were necessary for clinical testing, Lilly’s division director refused to purchase p-trifluoromethylphenol due to the high costs. Instead, he required that Molloy and his colleagues synthesize their own p-trifluoromethylphenol.
To that end, Molloy worked with Lilly scientist Edward Lavagnino (“Lavagnino”) to devise a cost efficient method of synthesizing p-trifluoromethylphenol. After experimenting with various prior art methods, Molloy concluded that those methods were inadequate for generating a sufficient amount of p-trifluoromethylphenol for use in clinical testing. Then, following further research, Molloy and Lavagnino developed their own method for preparing p-trifluo-romethylphenol that, as Lavagnino described in his deposition, was “superior” because it used “real cheap” starting material “available [in] tank car quantities.” Also, in an article written after the filing of the ’379 application, Molloy described his new synthesizing method as an improve
The ’081 and ’549 patents do not claim the material p-trifluoromethylphenol or a method for synthesizing it, nor do they disclose Molloy’s method for synthesizing it.
D. Best Mode: Recrystallization
While experimenting with compounds claimed in the ’081 and ’549 patents, Mol-loy recrystallized the compounds in order to remove impurities and enhance their suitability for pharmaceutical use. The recrystallization process involved using a solvent to dissolve a sample of the compound and then separating the desired product in crystalline form from the impurities that remained dissolved. Between February 1973 and January 1974, Molloy and other Lilly scientists experimented with various solvents for recrystallizing fluoxetine hydrochloride and eventually found a particular solvent that produced a higher yield and higher purity than other solvents.
The record evidence illustrates that while Lilly scientists knew that some solvents for recrystallizing fluoxetine hydrochloride were more effective than others, choosing a suitable recrystallization solvent was well known to one of ordinary skill in the art. In particular, Dr. Elias J. Corey (“Corey”), a Nobel laureate, testified that fluoxetine hydrochloride is “generally quite easy to purify by reerystalliza-ton.” Corey also explained that, although it requires some experimentation, selecting a recrystallization solvent is “very straightforward.” Further, Barr’s expert testified that “in 1974, sometimes the recrystallization of amine hydrochlorides was indeed routine.”
The ’081 and ’549 patents do not claim a process for recrystallizing fluoxetine hydrochloride nor do they disclose any solvents for use in the recrystallizing fluoxe-tine hydrochloride.
E. Double Patenting: The ’895 patent
On March 4, 1977, divisional application Serial No. 614,094 matured into the ’895 patent. Claim 1 of the ’895 patent, the only independent claim, provides as follows:
A method of treating human suffering from depression which comprises administering to said human an effective antidepressant dose of a compound of the formula:
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wherein each R’ is independently hydrogen or methyl; wherein R is naphthyl or
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*980 wherein R” and R’ ” are halo, trifluoro-methyl, C4 -C4 alkyl, C4 -C3 alkyloxy or C3 -C4 alkenyl; and wherein n and m are 0, 1 or 2; and acid addition salts thereof formed with a pharmaceutically-acceptable acid.
Put differently, claim 1 of the ’895 patent covers the administration of a pharmaceutical compound within a class of claimed compounds to treat depression in humans. The ’895 patent expired in April 1994.
II. STANDARD OF REVIEW
We review a district court’s grant of summary judgment de novo. See Conroy v. Reebok Int’l, Ltd.,
When evaluating a motion for summary judgment, the court views the record evidence through the prism of the evidentiary standard of proof that would pertain at a trial on the merits. See Anderson,
III. BEST MODE
Pursuant to section 112, ¶ 1, a patent specification must set forth the “best mode contemplated by the inventor of carrying out his invention.” 35 U.S.C. § 112, ¶ 1 (1994). The best mode requirement creates a statutory bargained-for-exchange by which a patentee obtains the right to exclude others from practicing the claimed invention for a certain time period, and the public receives knowledge of the preferred embodiments for practicing the claimed invention. See Spectra-Physics, Inc. v. Coherent, Inc.,
Our case law explicating the best mode requirement focuses on a two-prong inquiry. See Chemcast Corp. v. Arco Indus. Corp.,
With respect to the second prong of the best mode requirement, the extent of information that an inventor must disclose depends on the scope of the claimed invention. See Engel Indus. v. Lockformer Co.,
At the district court, Barr advanced two independent reasons for invalidating the ’081 and ’549 patents for failure to disclose the best mode: (1) Lilly failed to disclose Molloy’s preferred method for synthesizing p-trifluoromethylphenol, and (2) it failed to disclose Molloy’s preferred solvent for recrystallizing the fluoxetine hydrochloride compound. On cross motions for summary judgment, the district court held in favor of Lilly. Barr appeals, and we address each argument in turn.
A. Synthesizing p-trifluoromethylphenol
Barr contends that claim 5 of the ’081 patent and claim 7 of the ’549 patent do not meet the best mode requirement because the patents fail to disclose Molloy’s method for synthesizing p-trifluoromethylphenol. In the present case, even assuming that Molloy preferred his method for synthesizing p-trifluoromethylphenol to alternative means of obtaining the material, we hold that failure to disclose the synthesizing method does not contravene the best mode requirement.
We begin our analysis by examining the scope of the claimed inventions. See Engel Indus.,
Furthermore, the circumstances here are different from those in Dana Corp. v. IPC Ltd., Partnership,
To be sure, if the best mode for carrying out a claimed invention involves novel subject matter, then an inventor must disclose a method for obtaining that subject matter even if it is unclaimed. See Applied Med. Resources Corp. v. United States Surgical Corp.,
Barr contends that Clayton v. Akiba,
Barr also seizes upon portions of the record evidence in an effort to establish a best mode violation. For example, Barr relies on Lavagnino’s deposition testimony that Molloy’s method for synthesizing p-trifluoromethylphenol used material “available in tank car quantities, real cheap
Rather than establishing a best mode violation, this amalgam of evidence provides paradigmatic examples of production details that the law excepts from best mode disclosure. Indeed, this evidence relates to considerations of costs, volume, and available resources for manufacturing fluoxetine hydrochloride, all details that are superfluous to the best mode requirement. See Wahl Instruments,
B. Recrystallization Solvent
Barr also argues that claim 5 of the ’081 patent and claim 7 of the ’549 patent violate the best mode requirement because Molloy failed to disclose the particular recrystallization solvent that he used to purify fluoxetine hydrochloride. Even assuming that Molloy preferred a particular and specific recrystallization solvent to others, we hold that failure to disclose that solvent does not violate the best mode requirement.
Once again, we begin our analysis with the scope of the claimed invention. See Engel Indus.,
Barr contends that, even if choosing a solvent for recrystallization is a routine detail, the best mode requirement compels Molloy to disclose the particular and specific solvent he used in the recrystallization process. In effect, Barr argues that Mol-loy was obligated to disclose not only the preferred embodiment of the claimed invention but also the preferred solvent for the unclaimed recrystallization process. Stated at a higher level of generality, Barr asserts that a patentee must disclose a preferred mode for carrying out an unclaimed routine detail. That position, however, is in conflict with the scope of the claims at issue, our prior decisions, and the purpose undergirding the best mode requirement.
As we have often said, “[i]t is concealment of the best mode of practicing the claimed invention that section 112, ¶ 1 is designed to prohibit.” Chemcast,
Further, section 112 requires only “an adequate disclosure of the best mode.” Amgen, Inc. v. Chugai Pharm. Co., Ltd.,
Moreover, the purpose behind the best mode requirement supports our conclusion. As we explained in Amgen, the best mode requirement establishes a quid pro quo whereby the patentee “must not receive the right to exclude others unless at the time of filing he has provided an adequate disclosure of the best mode.”
In sum, because no genuine issue of material fact exists upon which a reasonable jury could find that claim 5 and claim 7 did not comply with the best mode requirement, we affirm the district court’s grant of summary judgment in favor of Lilly. Thus, we have no occasion to determine if Barr has a right to a jury trial on that issue.
Through a statutorily prescribed term, Congress limits the duration of a patentee’s right to exclude others from practicing a claimed invention. See 35 U.S.C. § 154(a)(2) (Supp.1998) (discussing the length of a patent term). The judicially-created doctrine of obviousness-type double patenting cements that legislative limitation by prohibiting a party from obtaining an extension of exclusive rights through claims in a later patent that are not patentably distinct from claims in an earlier patent. See In re Braat,
Obviousness-type double patenting entails a two-step analysis. First, as a matter of law, the court construes the claim in the earlier patent and the claim in the later patent, and it overlays the later claim on the earlier claim to determine whether the later claim encompasses subject matter previously claimed.
At the district court, Barr proffered three independent theories under which it sought to invalidate claim 7 of the ’549 patent for obviousness-type double patenting. On appeal, we limit our analysis to claim 1 of the ’895 patent. We begin by construing claim 1 of the ’895 patent and claim 7 of the ’549 patent to determine whether the former covers subject matter subsequently claimed in the latter. Claim 1 of the ’895 patent pertains to a method of treating depression in humans by administering a compound within the class of compounds defined by the following formula:
*986 [[Image here]]
wherein each R’ is independently hydrogen or methyl; wherein R is naphthyl or
[[Image here]]
wherein R” and R’ ” are halo, trifluoro-methyl, C4 -C4 alkyl, C4 -C3 alkyloxy or C3 -C4 alkenyl; and wherein n and m are 0, 1 or 2; and acid addition salts thereof formed with a pharmaceutically-acceptable acid.
Claim 7 of the ’549 patent claims a method for administering the compound fluoxe-tine hydrochloride to inhibit serotonin uptake. Claim 7 depends on claim 4, which claims a method of blocking the uptake of monoamines by administering a compound found within the same class of compounds that is defined by claim 1 of the ’895 patent. Thus, fluoxetine hydrochloride covered in claim 7 of the ’549 patent is also one of the compounds encompassed by claim 1 of the ’895 patent. It necessarily follows that claim 1 of the ’895 patent covered the administration of fluoxetine hydrochloride to treat depression.
Lilly argues that selecting fluoxetine hydrochloride from the class of compounds in claim 1 of the ’895 patent to treat depression would not have been obvious to one of ordinary skill in the art because that claim covers thousands of possible compounds. That argument, however, is of no consequence because double patenting is not “concerned with what one skilled in the art would be aware [of] from reading the claims but with what inventions the claims define.” In re Sarett,
Moreover, we find Lilly’s argument to be disingenuous because it seeks to use the broad coverage of claim 1 of the ’895 patent as both a sword and a shield. Throughout the term of the ’895 patent, by virtue of claim l’s broad coverage, Lilly
Having construed claim 1 of the ’895 patent and claim 7 of the ’549 patent and concluded that the use of fluoxetine hydrochloride is covered by the earlier claim, we must next determine whether there are any differences between the two claims that are patentably distinct. See Georgia-Pacific,
IY. CONCLUSION
In sum, because we hold that claim 5 of the ’081 patent and claim 7 of the ’549 patent comply with the best mode requirement and that claim 7 is invalid for obviousness-type double patenting, we affirm-in-part and reverse-in-part. Also, because we do not reach the issue, we vacate the district court’s grant of a jury trial to Barr.
AFFIRMED-IN-PART, REVERSED-IN-PART, AND VACATED.
COSTS
Each party bears its own costs.
Notes
. All other issues relating to validity were resolved by consent of the parties. As a re-suit, the district court's judgment disposed of all claims at issue.
. This section provides, in pertinent part, as follows:
An abbreviated application for a new drug shall contain ... a certification, in the opinion of the applicant and to the best of his knowledge, with respect to each patent which claims the listed drug ... for which the applicant is seeking approval under this subsection ... that such patent is invalid or will not be infringed by the manufacture, use, or sale of the new drug for which the application is submitted.
35 U.S.C. § 355(j)(2)(A)(vii)(IV).
. This section provides, in pertinent part, that "[i]t shall be an act of infringement to submit ... an application under . .. [the Hatch-Wax-man Act] ... for a drug claimed in a patent or the use of which is claimed in a patent.” 35 U.S.C. § 271(e)(2)(A).
. A patentee can cure invalidity for double patenting by filing a terminal disclaimer, thereby foregoing the portion of the term of the later patent that extends beyond the term of the earlier patent. In the present case, however, Lilly did not file a terminal disclaimer with respect to claim 7 of the '549 patent.
. An absence of overlap between the later claim and the earlier claim does not preclude a conclusion that the later claim is patentably indistinct from the earlier claim.
