Nobelpharma Ab v. Implant Innovations, Inc.

Nobelpharma AB and Nobelpharma USA, Inc. (collectively, NP) appeal from the judgment of the United States District Court for the Northern District of Illinois holding that (1) U.S. Patent 4,330,891 is invalid under 35 U.S.C. § 112, p 1 (1994), for failure to disclose the best mode of carrying out the invention, (2) Implant Innovations, Inc. (3I) did not infringe the '891 patent, and (3) NP was not entitled to JMOL or, in the alternative, a new trial following the jury verdict in favor of 3I on its antitrust counterclaim against NP, Dr. Per-Ingvar Branemark, and the Institute for Applied Biotechnology. See Nobelpharma AB v. Implant Innovations, Inc., 930 F.Supp. 1241 (N.D.Ill.1996). We conclude that the district court did not err in granting judgment that the patent is invalid as a matter of law at the close of NP's case-in-chief, and that it did not err in denying NP's motion for JMOL or a new trial on the antitrust counterclaim. Accordingly, the decision of the district court is affirmed.1

Drs. Branemark and Bo-Thuresson af Ekenstam are the named inventors on the '891 patent, the application for which was filed in 1980 and claimed priority from a Swedish patent application that was filed in 1979. The patent claims "an element intended for implantation into bone tissue." This "element," when used as part of a dental implant, is placed directly into the jawbone where it acts as a tooth root substitute. The implants described and claimed in the patent are preferably made of titanium and have a network of particularly-sized and particularly-spaced "micropits." These micropits, which have diameters in the range of about 10 to 1000 nanometers or, preferably, 10 to 300 nanometers, allow a secure connection to form between the implant and growing bone tissue through a process called "osseointegration."

Branemark is also one of the authors of a book published in 1977, entitled "Osseointegrated Implants in the Treatment of the Edentulous Jaw Experienced from a 10-Year Period" (hereinafter "the 1977 Book"). As its title suggests, this book describes a decade-long clinical evaluation of patients who had received dental implants. The 1977 Book includes a single page containing four scanning electron micrographs (SEMs) of titanium implants that exhibit micropits. The caption describing these SEMs reads, in part: "Irregularities are produced during manufacturing in order to increase the retention of the implants within the mineralized tissue." 3I determined, based on measurements and calculations that it presented to the trial court, that the micropits shown in the 1977 Book have diameters within the range claimed in the '891 patent. However, the 1977 Book does not specifically refer to "micropits."

In preparing to file the Swedish patent application, af Ekenstam submitted a draft written description of the invention to the inventors' Swedish patent agent, Mr. Barnieske. This draft referred to the 1977 Book in the following translated passage:

In ten years of material pertaining to titanium jaw implants in man, Branemark et al. [in the 1977 Book] have shown that a very high frequency of healing, as stated above, can be achieved by utilizing a carefully developed surgical technique and adequately produced implants.

However, Barnieske deleted all reference to the 1977 Book from the patent application that was ultimately filed in Sweden. Similarly, the 1977 Book is not mentioned in the U.S. patent application filed by Barnieske on behalf of Branemark and af Ekenstam.

In June 1980, while the U.S. patent application was pending, Branemark entered into an exclusive license agreement with NP covering the claimed technology.2 Barnieske kept NP informed of the prosecution of the U.S. patent application and received assistance from NP's U.S. patent agent. The '891 patent issued in 1982; NP has since asserted it in at least three patent infringement suits.

In July 1991, while Branemark was a member of NP's Board of Directors, NP brought this suit alleging that certain of 3I's dental implants infringed the '891 patent. 3I defended on the grounds of invalidity, unenforceability, and non-infringement. 3I also brought an antitrust counterclaim, based in part on the assertion that NP attempted to enforce a patent that it knew was invalid and unenforceable. Specifically, 3I alleged that when NP brought suit, NP was aware that the inventors' intentional failure to disclose the 1977 Book to the U.S. Patent and Trademark Office (PTO) would render the '891 patent unenforceable.

During its case-in-chief, NP introduced portions of a deposition of Branemark that apparently was conducted several years before this trial began in connection with a lawsuit involving neither NP nor 3I. NP also introduced into evidence portions of that deposition that were counter-designated for introduction by 3I. Branemark's deposition testimony included his admissions that one "could consider" the procedure used to manufacture the micropitted surface a trade secret, and "it might be" that there are details "important to making" the micropitted surface that are not disclosed in the patent. At the close of NP's case-in-chief, the district court granted 3I's motion for JMOL of invalidity and non-infringement. The court held that the patent was invalid under § 112, p 1, for failure to disclose the best mode and that NP had failed to prove infringement. The court then denied NP's motion for JMOL on 3I's antitrust counterclaim, proceeded to inform the jury that the court had held the patent invalid, and allowed 3I to present the counterclaim to the jury.

After trial limited to the antitrust issue, the jury found in special verdicts, inter alia, that 3I had proven that (1) "the inventors or their agents or attorneys obtained the '891 patent through fraud," (2) NP "had knowledge that the '891 patent was obtained by fraud at the time this action was commenced against 3I," and (3) NP "brought this lawsuit against 3I knowing that the '891 patent was either invalid or unenforceable and with the intent of interfering directly with 3I's ability to compete in the relevant market." The jury awarded 3I approximately $3.3 million in compensatory damages, an amount the court trebled pursuant to section 4 of the Clayton Act, 15 U.S.C. § 15 (1994). The court declined to rule on whether the patent was unenforceable for inequitable conduct, concluding that its judgment of invalidity rendered the issue of enforceability moot. Nobelpharma AB v. Implant Innovations, Inc., 875 F.Supp. 481, 34 USPQ2d 1090 (N.D.Ill.1995).

The court then denied NP's renewed motion for JMOL on the counterclaim or, in the alternative, for a new trial on both the counterclaim and the infringement claim. Nobelpharma AB, 930 F.Supp. at 1246. In denying NP's post-verdict motion for a new trial on the issue of infringement, the district court again concluded that the patent was invalid for failure to disclose the best mode. Id. at 1247-49. The court also concluded that NP was not entitled to JMOL on the counterclaim because, inter alia, "NP, as the assignee of the patent, maintained and enforced the patent with knowledge of the patent's fraudulent derivation." Id. at 1257. The court denied NP's motion for a new trial on the counterclaim, holding, inter alia, that it did not err in its evidentiary rulings or in refusing to instruct the jury that in order to impose antitrust liability against NP, it must find NP's lawsuit "objectively baseless." Id. at 1264.

NP appealed to this court, challenging the district court's grant of 3I's motion for JMOL of invalidity and non-infringement and its denial of the post-verdict motion for JMOL or a new trial. We have jurisdiction pursuant to 28 U.S.C. § 1295(a)(1) (1994).

At the close of NP's case-in-chief, the district court granted 3I's motion for judgment of invalidity under § 112, p 1, as a matter of law for failure to disclose the best mode of practicing the invention. NP then filed a motion for reconsideration, which was denied, in order to reopen the evidence and offer proof regarding its compliance with § 112, p 1. After the jury returned its verdict in favor of 3I on its antitrust counterclaim, NP moved for a new trial, again arguing that the court had erred in granting 3I's motion for JMOL. In reaffirming its decision to grant 3I's motion for JMOL, the district court held that Branemark's own testimony "demonstrates that when [he] filed his patent application, he contemplated a best mode of practicing his invention, but his disclosures were inadequate to enable one skilled in the art to practice that best mode." 930 F.Supp. at 1248. The district court also explicitly noted that its decision was not based on Branemark's purported "non-disclosure" of NP's later-developed manufacturing procedure. Id.

On appeal, NP again argues that the district court erred in granting JMOL on the invalidity issue because in doing so the court drew improper, unsupported inferences against NP and erroneously imposed on NP the burden of proving validity. NP also argues that the grant of JMOL denied it due process because the court had mandated a "natural order of proof" at trial and thus had effectively barred NP from introducing any evidence to show that it had satisfied the best mode requirement during its case-in-chief.

In response, 3I argues that Branemark's own unequivocal admissions indicate that he had developed and tested a preferred method of making the claimed implants when the patent application was filed. 3I also argues that Branemark admitted that the patent does not contain a disclosure adequate to enable one of ordinary skill in the art to practice this method. Finally, 3I argues that NP was not denied due process because NP had sufficient opportunity to offer evidence in opposition to 3I's motion for JMOL of invalidity and failed to do so. We agree with 3I that the court did not err in its grant of the motion for JMOL and therefore that the court did not err in denying NP's motion for a new trial on its infringement claim.

We review a district court's grant of a motion for JMOL under Fed.R.Civ.P. 50(a)(1) de novo by reapplying the standard applicable at the district court. See Allied Colloids Inc. v. American Cyanamid Co., 64 F.3d 1570, 1573, 35 USPQ2d 1840, 1841 (Fed.Cir.1995). Under that standard, we examine the record in the light most favorable to the non-movant, which in this case is NP, and afford it the benefit of all reasonable inferences. Id. Accordingly, "[w]e may affirm only if the judgment entered was the only one possible under the controlling law." Burroughs Wellcome Co. v. Barr Lab., Inc., 40 F.3d 1223, 1227, 32 USPQ2d 1915, 1919 (Fed.Cir.1994), cert. denied, 516 U.S. 1070, 116 S.Ct. 771 (1996) (citing Anderson v. Liberty Lobby, Inc., 477 U.S. 242, 250, 106 S.Ct. 2505, 2511, 91 L.Ed.2d 202 (1986) (prohibiting JMOL "[i]f reasonable minds could differ as to the import of the evidence.")).

Rule 50(a)(1) provides, in relevant part, that if

a party has been fully heard on an issue and there is no legally sufficient evidentiary basis for a reasonable jury to find for that party on that issue, the court may determine the issue against that party and may grant a motion for judgment as a matter of law [JMOL] against that party with respect to a claim or defense that cannot under the controlling law be maintained or defeated without a favorable finding on that issue.

Fed.R.Civ.P. 50(a). "Thus, the verdict may be directed after the plaintiff's case is presented, when it is clear that completion of the trial is unnecessary in that the only sustainable verdict could be in favor of the defendant." Allied Colloids, 64 F.3d at 1573, 35 USPQ2d at 1841.

By statute, patents are presumed to be valid. 35 U.S.C. § 282 (1994). Thus, 3I had the burden of establishing by clear and convincing evidence facts supporting the conclusion that the '891 patent is invalid. See Transco Prods. Inc. v. Performance Contracting, Inc., 38 F.3d 551, 560, 32 USPQ2d 1077, 1084 (Fed.Cir.1994). The patent statute requires that a patent specification "shall set forth the best mode contemplated by the inventor of carrying out his invention." 35 U.S.C. § 112, p 1 (1994). Determining whether a patent fails to comply with the best mode requirement and is thus invalid involves two factual inquiries. First, the fact-finder must determine whether at the time an applicant filed an application for patent, he or she had a best mode of practicing the invention, which is a subjective determination. Second, if the inventor had a best mode of practicing the invention, the fact-finder must determine whether the best mode was disclosed in sufficient detail to allow a skilled artisan to practice it without undue experimentation, which is an objective determination. See United States Gypsum Co. v. National Gypsum Co., 74 F.3d 1209, 1212, 37 USPQ2d 1388, 1390 (Fed.Cir.1996).

For whatever reason, NP introduced as part of its own case-in-chief all of the portions of Branemark's deposition that were counter-designated by 3I.3 These included Branemark's statements, introduced by and unchallenged by NP, that (1) "there were some minor details that were not included [in the patent] and which proved to be quite important," (2) other skilled artisans would have to be "lucky" to obtain a suitable micropitted implant "by cutting a piece of titanium at a speed less than twenty meters per minute," the cutting speed disclosed in the patent, and (3) "any of the small detailed recipes that I discussed but did not specify" in the patent "can cause you to fail to get micropitting even though you were cutting the metal at less than twenty meters per minute." The record also unambiguously indicates that when he filed his patent application, Branemark was aware that a variety of undisclosed machining parameters were critical to the production of a functional implant, i.e., one that would allow for osseointegration. Moreover, the research on which the 1977 Book was based also indicates that Branemark possessed a preferred mode of making the claimed implants by the time the U.S. patent application was filed in 1980. Thus, the evidence at trial leads to only one reasonable conclusion: Branemark possessed a preferred method of making the claimed invention and failed to disclose it sufficiently to enable those skilled in the art to practice that method.

Normally, evidence presented by a patentee-plaintiff will not support a grant of a JMOL invalidating a patent. That is because the burden is on an accused infringer to show by clear and convincing evidence facts supporting the conclusion that the patent is invalid. See generally 9A Charles Alan Wright & Arthur R. Miller, Federal Practice and Procedure § 2535, at 325 (2d ed. 1994) ("[C]ourts often caution that granting a [JMOL] for the party bearing the burden of proof is reserved for extreme cases."). Accordingly, grant of JMOL in favor of a party bearing the burden of proof may be granted only where (1) the movant "has established [its] case by evidence that the jury would not be at liberty to disbelieve" and (2) "the only reasonable conclusion is in [the movant's] favor." Hurd v. American Hoist & Derrick Co., 734 F.2d 495, 499 (10th Cir.1984). However, in unusual cases, an admission made by a plaintiff's witness can be sufficient to support entry of a JMOL in favor of a defendant after the close of the plaintiff's case-in-chief, even where the defendant bears the burden of proof on the decided issue. See, e.g., Falco Lime, Inc. v. Tide Towing Co., 29 F.3d 362, 365-66 (8th Cir.1994) (holding that JMOL was properly granted after the close of plaintiff's case in view of the admissions of plaintiff's chief witness regarding a contract that established defendant's affirmative defense). Given Branemark's admissions, we conclude that this is one of those "extreme" cases in which it was not improper to grant JMOL in favor of a defendant on an issue regarding which it bore the burden of proof.

Contrary to NP's arguments, the district court did not draw adverse inferences against NP to support its judgment. Rather, it properly relied on a co-inventor's statements "that the jury would not be at liberty to disbelieve." Hurd, 734 F.2d at 499. Similarly, the district court did not place the burden of proving validity on NP; NP's own evidence was clear and convincing that the patent is invalid. This evidence led to "the only reasonable conclusion." Id.

We also agree with 3I that NP was not denied due process. When NP was confronted with 3I's motion for JMOL, it was not unfairly surprised. 3I had consistently alleged that the '891 patent was invalid under § 112, p 1. Moreover, NP had an opportunity to oppose 3I's motion, but it failed to do so adequately. After the court's grant of JMOL, NP responded by offering evidence and argument only concerning NP's later-developed manufacturing procedure. However, as noted above, the district court's ultimate decision did not rely on the "non-disclosure" of NP's later-developed manufacturing processes. Likewise, in affirming the decision of the district court, we do not rely on that evidence. Rather, we rely only on the clear and convincing evidence that Branemark failed to disclose his best mode of practicing the claimed invention when he filed his patent application. NP failed to present any evidence or argument to undermine the import of that evidence, even though it knew that the best mode issue was before the court; it thus had ample opportunity to prepare and present evidence and argument. Whatever disadvantage NP may have suffered when the JMOL was granted was rectified by the opportunity it had after the judgment was rendered. Any error was thus harmless. NP was therefore not denied due process.

Accordingly, we affirm the judgment that the '891 patent is invalid as a matter of law under § 112, p 1, for failure to disclose the best mode of practicing the invention. Because we affirm the district court's decision holding the patent invalid, we need not consider NP's arguments concerning infringement. See B.F. Goodrich Co. v. Aircraft Braking Sys. Corp., 72 F.3d 1577, 1583, 37 USPQ2d 1314, 1319 (Fed.Cir.1996).

After the jury returned its verdict in favor of 3I on its counterclaim that NP violated the antitrust laws by bringing suit against 3I, the court denied NP's motion for JMOL or, in the alternative, for a new trial under Fed.R.Civ.P. 50(b). In denying NP's motion, the district court held that the verdict was supported, inter alia, by the jury's factual findings that the patent was obtained through "NP's knowing fraud upon, or intentional misrepresentations to, the [PTO]" and that "NP maintained and enforced the patent with knowledge of the patent's fraudulent derivation" and with the intent of interfering directly with 3I's ability to compete in the relevant market. 930 F.Supp. at 1257. The court further held, based on these findings, that the jury need not have considered whether NP's suit was "objectively baseless." Id. at 1264.

In support of its position that the court erred in denying its renewed motion for JMOL, NP argues that there was a lack of substantial evidence to support the jury's findings that the patent was obtained through "fraud" and that NP was aware of that conduct when it brought suit against 3I. NP also argues that these findings, even if supported by substantial evidence, do not provide a legal basis for the imposition of antitrust liability. Finally, NP argues that it is entitled to a new trial because the court failed to instruct the jury that bringing a lawsuit cannot be the basis for antitrust liability if that suit is not "objectively baseless."

3I responds that the jury's explicit findings that the patent was procured through fraudulent conduct and that NP knew of that conduct when it brought suit were supported by substantial evidence, and that these findings provide a sound basis for imposing antitrust liability on NP. Responding to NP's arguments for a new trial, 3I argues that an "objectively reasonable" or "objectively baseless" jury instruction was not necessary because the district court required that 3I prove that NP had actual knowledge of the fraud when it brought suit and that even if such an instruction had been necessary, NP waived this argument by failing to propose a jury instruction relating to an "objectively baseless" standard. We agree with 3I that the court did not err in denying NP's motion for JMOL because substantial evidence supports the jury's findings that the patent was fraudulently obtained and that NP sought to enforce the patent with knowledge of its fraudulent origin. Similarly, the court did not err in denying NP's motion for a new trial because NP was not prejudiced by any legally erroneous jury instruction.

We review a district court's denial of a post-trial motion for JMOL under Fed.R.Civ.P. 50(b) de novo by reapplying the standard applicable at the district court. Thus, this court

must determine whether there exists evidence of record upon which a jury might properly have returned a verdict in [the non-movant's] favor when the correct legal standard is applied. If there is not, [the movant] was entitled to have the question removed from the jury and decided as a matter of law.

Markman v. Westview Instruments, Inc., 52 F.3d 967, 975, 34 USPQ2d 1321, 1326 (Fed.Cir.1995) (in banc) (quoting Jamesbury Corp. v. Litton Indus. Prods., Inc., 756 F.2d 1556, 1560, 225 USPQ 253, 257 (Fed.Cir.1985)), aff'd, 517 U.S. 370, 116 S.Ct. 1384, 134 L.Ed.2d 577, 38 USPQ2d 1461 (1996); see also Deimer v. Cincinnati Sub-Zero Prods., Inc., 58 F.3d 341, 343 (7th Cir.1995); Shearing v. Iolab Corp., 975 F.2d 1541, 1544, 24 USPQ2d 1133, 1136 (Fed.Cir.1992) ("On appeal after denial of a motion for JNOV, the appellant must prove that the record lacks substantial evidence to support the jury's verdict."). In applying this standard, we must also "view the evidence in the light most favorable to the nonmoving party," which in this case is 3I. Deimer, 58 F.3d at 343.

We review a district court's denial of a motion for a new trial for an abuse of discretion. Railroad Dynamics, Inc. v. A. Stucki Co., 727 F.2d 1506, 1512, 220 USPQ 929, 936 (Fed.Cir.1984). Accordingly, we may reverse the district court if, inter alia, the district court prejudiced NP's substantive rights by abusing its discretion in admitting or excluding evidence, see Munoz v. Strahm Farms, Inc., 69 F.3d 501, 36 USPQ2d 1499, 1501 (Fed.Cir.1995), or by giving legally erroneous jury instructions, see Jamesbury, 756 F.2d at 1558, 225 USPQ at 255. See generally 12 McLaughlin et al., Moore's Federal Practice § 59.20 to 59.25, at 59-27 to 59-47 (3d ed.1997).

As a general proposition, when reviewing a district court's judgment involving federal antitrust law, we are guided by the law of the regional circuit in which that district court sits. See Loctite Corp. v. Ultraseal Ltd., 781 F.2d 861, 875, 228 USPQ 90, 99 (Fed.Cir.1985) ("We must approach a federal antitrust claim as would a court of appeals in the circuit of the district court whose judgment we review.") (citing Atari, Inc. v. JS & A Group, Inc., 747 F.2d 1422, 1438-40, 223 USPQ 1074, 1086-87 (Fed.Cir.1984) (in banc)); see also Cygnus Therapeutics Sys. v. ALZA Corp., 92 F.3d 1153, 1161, 39 USPQ2d 1666, 1672 (Fed.Cir.1996) (citing Loctite ). However, we apply our own law, not regional circuit law, to resolve issues that clearly involve our exclusive jurisdiction. See Pro-Mold & Tool Co. v. Great Lakes Plastics, Inc., 75 F.3d 1568, 1574-75, 37 USPQ2d 1626, 1631 (Fed.Cir.1996) (holding as a matter of Federal Circuit law that an allegation of inequitable conduct in the prosecution of a patent application cannot support a federal unfair competition claim) (citing Chrysler Motors Corp. v. Auto Body Panels, Inc., 908 F.2d 951, 953 15 USPQ2d 1469, 1470 (Fed.Cir.1990)). See generally Biodex Corp. v. Loredan Biomedical, Inc., 946 F.2d 850, 855-58, 20 USPQ2d 1252, 1256-59 (Fed.Cir.1991).

Whether conduct in the prosecution of a patent is sufficient to strip a patentee of its immunity from the antitrust laws is one of those issues that clearly involves our exclusive jurisdiction over patent cases. It follows that whether a patent infringement suit is based on a fraudulently procured patent impacts our exclusive jurisdiction.

Moreover, an antitrust claim premised on stripping a patentee of its immunity from the antitrust laws is typically raised as a counterclaim by a defendant in a patent infringement suit. See Argus Chem. Corp. v. Fibre Glass-Evercoat Co., 812 F.2d 1381, 1383, 1 USPQ2d 1971, 1973 (Fed.Cir.1987) ("Walker Process, like the present case, was a patent infringement suit in which an accused infringer filed an antitrust counterclaim.").4 Because most cases involving these issues will therefore be appealed to this court, we conclude that we should decide these issues as a matter of Federal Circuit law, rather than rely on various regional precedents. We arrive at this conclusion because we are in the best position to create a uniform body of federal law on this subject and thereby avoid the "danger of confusion [that] might be enhanced if this court were to embark on an effort to interpret the laws" of the regional circuits. Forman v. United States, 767 F.2d 875, 880 n. 6 (Fed.Cir.1985). Accordingly, we hereby change our precedent and hold that whether conduct in procuring or enforcing a patent is sufficient to strip a patentee of its immunity from the antitrust laws is to be decided as a question of Federal Circuit law.5 This conclusion applies equally to all antitrust claims premised on the bringing of a patent infringement suit. Therefore, Cygnus, 92 F.3d at 1161, 39 USPQ2d at 1672, Loctite, 781 F.2d at 875, 228 USPQ at 99, and Atari, 747 F.2d at 1438-40, 223 USPQ at 1086-87, are expressly overruled to the extent they hold otherwise. However, we will continue to apply the law of the appropriate regional circuit to issues involving other elements of antitrust law such as relevant market, market power, damages, etc., as those issues are not unique to patent law, which is subject to our exclusive jurisdiction. See, e.g., Virginia Panel Corp. v. MAC Panel Co., 133 F.3d 860, 872-73, 45 USPQ2d 1225, 1234-35 (Fed.Cir.1997) (applying Fourth Circuit law on antitrust injury).

A patentee who brings an infringement suit may be subject to antitrust liability for the anti-competitive effects of that suit if the alleged infringer (the antitrust plaintiff) proves (1) that the asserted patent was obtained through knowing and willful fraud within the meaning of Walker Process Equipment, Inc. v. Food Machinery & Chemical Corp., 382 U.S. 172, 177, 86 S.Ct. at 350, 147 USPQ 404, 407 (1965), or (2) that the infringement suit was "a mere sham to cover what is actually nothing more than an attempt to interfere directly with the business relationships of a competitor," Eastern R.R. Presidents Conference v. Noerr Motor Freight, Inc., 365 U.S. 127, 144, 81 S.Ct. 523, 533, 5 L.Ed.2d 464 (1961); California Motor Transp. Co. v. Trucking Unlimited, 404 U.S. 508, 510, 92 S.Ct. 609, 611-612, 30 L.Ed.2d 642 (1972) (holding that Noerr "governs the approach of citizens or groups of them ... to courts, the third branch of Government"). See Professional Real Estate Investors, Inc. v. Columbia Pictures Indus., Inc., 508 U.S. 49, 62 n. 6, 113 S.Ct. 1920, 1929 n. 6, 123 L.Ed.2d 611, 26 USPQ2d 1641, 1646-47 n. 6 (1993) (PRE ) (declining to decide "whether and, if so, to what extent Noerr permits the imposition of antitrust liability for a litigant's fraud or other misrepresentations").

In Walker Process, the Supreme Court held that in order "to strip [a patentee] of its exemption from the antitrust laws" because of its attempting to enforce its patent monopoly, an antitrust plaintiff is first required to prove that the patentee "obtained the patent by knowingly and willfully misrepresenting facts6 to the [PTO]." 382 U.S. at 177, 86 S.Ct. at 350,