The New 'Material Effect' Test

In Bayer AG v. Schein Pharm., Inc., 301 F.3d 1306 (Fed. Cir. 2002), the Federal Circuit articulated a new 'material effect' test for the best mode requirement. The court affirmed the validity of a patent covering the antibiotic drug ciprofloxacin on the grounds that it properly claimed priority to a parent application that satisfied the best mode requirement. With the priority date of the parent application, the patent was not invalidated under section 102(d) by an earlier filed foreign patent. The three-judge panel agreed that the parent application met the best mode requirement; however, the panel disagreed as to why the best mode requirement was satisfied. The majority reviewed the prior case law and found 'that the best mode of making and using the invention need be disclosed if it materially affects the properties of the claimed invention.' Id. at 1319-1320. Judge Radar concurred in the result, but strenuously objected to the creation of this additional criterion.

Majority Opinion

The majority began its analysis by examining the scope of the best mode requirement. The analysis began with a review of In re Brebner, 455 F.2d 1402 (C.C.P.A. 1972), wherein the Court of Customs and Patent Appeals held that the method of making two polymers was not within the scope of the best mode because the invention was the blend of the two polymers, not the starting materials. After reviewing the intervening case law, the Bayer majority noted that the scope of the best mode requirement is determined by the scope of the claims. However, the majority then reviewed those cases where the Federal Circuit held patents invalid for failing to disclose the best mode. Four of the seven cases issued during the late 1980s and early 1990s. During this period, the Federal Circuit had the broadest interpretation for the best mode requirement, extending beyond the scope of the claimed invention. In Northern Telecom, Inc. v. Datapoint Corp., 908 F.2d 931 (Fed. Cir. 1990), for example, the Court found that the patent at issue was invalid for failing to disclose the inventor's preferred audio cassette for use in the claimed invention, even though the claims covered only the device and not the audio cassette. In Bayer, however, the majority held that, in order to satisfy the best mode requirement, an inventor's preferred mode must be disclosed if it materially affects the properties of the claimed invention. This includes preferred modes outside the scope of the claims. Applying this standard, the Court ultimately found that the best mode was satisfied because the inventor's preferred mode did not affect the properties of the claimed invention.

Concurring Opinion

Judge Rader began his analysis at the same point as the majority, by examining the scope of the best mode requirement. He reviewed the current jurisprudence and also concluded that the scope of the best mode requirement is limited to the claims. His analysis then diverged from that of the majority. He reviewed current cases where the Federal Circuit held that a preferred mode was not a best mode and therefore did not have to be disclosed. Judge Rader summarized, '[A] review of the totality of this Circuit's best mode cases, as opposed to a few cases that found a violation, shows that this court does not use an 'effect on properties' test to identify best modes, but instead uses a scope of the claimed invention test.' Id. at 1327 Applying the scope of the claimed invention test, Judge Rader concluded that the inventor's preferred mode was not within the scope of the claims, so it did not have to be disclosed to satisfy the best mode requirement.

Significance

The impact of this case will depend upon whether and how district courts apply this additional criterion and upon whether future Federal Circuit opinions follow this recent decision. At its broadest, the material effect test would expand the scope of the best mode requirement. As forecast by Judge Rader, 'this Bayer opinion widens its best mode net to capture the properties of the claimed invention and further sweeps in any material effect or impact on those properties.' Id. at 1324. This is indeed how the majority applied the material effect test. But this was based upon the majority's review of the case law that included a number of cases from the late eighties and early nineties. These cases represent a high water mark in the scope of disclosure required to comply with the best mode.

If district courts continue to apply the current Federal Circuit jurisprudence for the scope of the best mode requirement, then this opinion will not act as a broom, sweeping in any material effect on the properties of the claimed mode. Rather, this opinion could narrow the scope of disclosure required under the best mode. As Judge Rader indicated, the current jurisprudence limits the scope of the best mode to the claimed invention. If courts apply the material effect test only after determining whether the alleged mode is within the scope of the claimed invention, then some preferred modes would no longer be best modes. An example would be a mode that an inventor subjectively preferred that was no better than the disclosed mode. Such a preferred mode would not materially affect the properties of the claimed invention and therefore would not need to be disclosed to satisfy the best mode.

For patent prosecutors, this case merely reinforces the need to disclose as fully as possible. Even if this case does not expand the scope of the best mode requirement, the scope could be expanded by future opinions from the Federal Circuit as it was during the late eighties and early nineties. Since such a change in scope is merely a change in precedence and not a change in the statute, a patent prosecutor cannot rely on the scope of the best mode at the time of drafting the application. Rather, the application must be sufficiently robust to withstand the waxing and waning scope of the best mode requirement throughout the life of the patent. The case is also of interest to patent litigators because it provides arguments for both an expanded and a narrowed scope for the best mode requirement.

Otis Littlefield is an associate in the San Francisco office of Morrison & Foerster, where he is a member of the Intellectual Property and Technology Transactions groups.

In Bayer AG v. Schein Pharm., Inc., 301 F.3d 1306 (Fed. Cir. 2002), the Federal Circuit articulated a new 'material effect' test for the best mode requirement. The court affirmed the validity of a patent covering the antibiotic drug ciprofloxacin on the grounds that it properly claimed priority to a parent application that satisfied the best mode requirement. With the priority date of the parent application, the patent was not invalidated under section 102(d) by an earlier filed foreign patent. The three-judge panel agreed that the parent application met the best mode requirement; however, the panel disagreed as to why the best mode requirement was satisfied. The majority reviewed the prior case law and found 'that the best mode of making and using the invention need be disclosed if it materially affects the properties of the claimed invention.' Id. at 1319-1320. Judge Radar concurred in the result, but strenuously objected to the creation of this additional criterion.

Majority Opinion

The majority began its analysis by examining the scope of the best mode requirement. The analysis began with a review of In re Brebner, 455 F.2d 1402 (C.C.P.A. 1972), wherein the Court of Customs and Patent Appeals held that the method of making two polymers was not within the scope of the best mode because the invention was the blend of the two polymers, not the starting materials. After reviewing the intervening case law, the Bayer majority noted that the scope of the best mode requirement is determined by the scope of the claims. However, the majority then reviewed those cases where the Federal Circuit held patents invalid for failing to disclose the best mode. Four of the seven cases issued during the late 1980s and early 1990s. During this period, the Federal Circuit had the broadest interpretation for the best mode requirement, extending beyond the scope of the claimed invention. In Northern Telecom, Inc. v. Datapoint Corp., 908 F.2d 931 (Fed. Cir. 1990), for example, the Court found that the patent at issue was invalid for failing to disclose the inventor's preferred audio cassette for use in the claimed invention, even though the claims covered only the device and not the audio cassette. In Bayer, however, the majority held that, in order to satisfy the best mode requirement, an inventor's preferred mode must be disclosed if it materially affects the properties of the claimed invention. This includes preferred modes outside the scope of the claims. Applying this standard, the Court ultimately found that the best mode was satisfied because the inventor's preferred mode did not affect the properties of the claimed invention.

Concurring Opinion

Judge Rader began his analysis at the same point as the majority, by examining the scope of the best mode requirement. He reviewed the current jurisprudence and also concluded that the scope of the best mode requirement is limited to the claims. His analysis then diverged from that of the majority. He reviewed current cases where the Federal Circuit held that a preferred mode was not a best mode and therefore did not have to be disclosed. Judge Rader summarized, '[A] review of the totality of this Circuit's best mode cases, as opposed to a few cases that found a violation, shows that this court does not use an 'effect on properties' test to identify best modes, but instead uses a scope of the claimed invention test.' Id. at 1327 Applying the scope of the claimed invention test, Judge Rader concluded that the inventor's preferred mode was not within the scope of the claims, so it did not have to be disclosed to satisfy the best mode requirement.

Significance

The impact of this case will depend upon whether and how district courts apply this additional criterion and upon whether future Federal Circuit opinions follow this recent decision. At its broadest, the material effect test would expand the scope of the best mode requirement. As forecast by Judge Rader, 'this Bayer opinion widens its best mode net to capture the properties of the claimed invention and further sweeps in any material effect or impact on those properties.' Id. at 1324. This is indeed how the majority applied the material effect test. But this was based upon the majority's review of the case law that included a number of cases from the late eighties and early nineties. These cases represent a high water mark in the scope of disclosure required to comply with the best mode.

If district courts continue to apply the current Federal Circuit jurisprudence for the scope of the best mode requirement, then this opinion will not act as a broom, sweeping in any material effect on the properties of the claimed mode. Rather, this opinion could narrow the scope of disclosure required under the best mode. As Judge Rader indicated, the current jurisprudence limits the scope of the best mode to the claimed invention. If courts apply the material effect test only after determining whether the alleged mode is within the scope of the claimed invention, then some preferred modes would no longer be best modes. An example would be a mode that an inventor subjectively preferred that was no better than the disclosed mode. Such a preferred mode would not materially affect the properties of the claimed invention and therefore would not need to be disclosed to satisfy the best mode.

For patent prosecutors, this case merely reinforces the need to disclose as fully as possible. Even if this case does not expand the scope of the best mode requirement, the scope could be expanded by future opinions from the Federal Circuit as it was during the late eighties and early nineties. Since such a change in scope is merely a change in precedence and not a change in the statute, a patent prosecutor cannot rely on the scope of the best mode at the time of drafting the application. Rather, the application must be sufficiently robust to withstand the waxing and waning scope of the best mode requirement throughout the life of the patent. The case is also of interest to patent litigators because it provides arguments for both an expanded and a narrowed scope for the best mode requirement.

Otis Littlefield is an associate in the San Francisco office of Morrison & Foerster, where he is a member of the Intellectual Property and Technology Transactions groups.