In Re Swanson
This is an appeal from the United States Patent and Trademark Office’s (“PTO”) Board of Patent Appeals and Interferences (“Board”). The Board upheld the examiner’s rejection of claims 22-25 of U.S. Patent No. 5,073,484 (“the '484 patent”) in a reexamination proceeding.
In re Swanson,
No.2005-0725, Reexamination No. 90/006,785 (B.P.A.I. May 29, 2007). Previously, this court had affirmed a district court judgment that claims 22 and 23 of the '484 patent were not invalid.
Abbott Labs. v. Syntron Bioresearch, Inc.,
I.
A. The '484 Patent
The '484 patent was filed on February 23, 1983, by Melvin Swanson and Patrick Guire. The patent discloses a method of quantitatively analyzing small amounts of biological fluids, such as milk, blood, and urine, or other solutions, to detect the presence of a particular substance (the analyte). In the method disclosed, one or more “reaction zones” containing a bound reactant are spaced out on a test strip made of a liquid-permeable solid. '484 patent col.2 11.6-10. A test solution is applied to the test strip and moves along a flow path, encountering these reactant-containing zones sequentially. When a solution containing the requisite analyte reaches each of the reaction zones, a predetermined product forms. Id. col.2 11.12-14. Selected detectors in the reaction zones indicate, preferably by a change of color, the presence of analyte, reactant, or predetermined product. Id. col.8 11.47-54. The specification does not limit the invention to any one type of detection and suggests that the analyte can be “substantially all chemical substances that are reactive with a reactant to form a product.” Id. eol.7 11.16-19.
Claim 22, the independent claim at issue, is characteristic of the patent and claims a method of detection in which the analyte and reactant form a ligand-antiligand binding pair:
A method for analysis of an analyte which is a member of a ligand-antiligand binding pair in a test solution comprising the steps of:
(a) providing a non-diffusively immobilized reactant in each of one or more reaction zones spaced successively along a flow path defined by a liquid permeable medium, wherein said reactant is the other member of said binding pair and is capable of binding with the analyte to form a predetermined product;
(b) flowing said solution along the medium and sequentially through the reaction zone(s); and
(c) detecting the presence of analyte, said reactant or said predetermined product in the reaction zone(s), wherein the number of zones in which detection occurs is related to the presence [sic] of analyte solution.
Id. col. 18 11.9-25. A preferred embodiment is an immunoassay, in which the ligandantiligand pair is an antigen-antibody pair.
In addition to claim 22, there are three dependent claims relevant to this appeal: claims 23, 24, and 25. Claim 23 limits the ligand-antiligand pair by requiring that one part of the pair be “labeled with a chemical moiety, and wherein such detecting step comprises detecting the presence of said chemical moiety.” Id. eol.18 11.26— 30. Claims 24 and 25 additionally limit the chemical moiety to including an enzyme and being a radioisotope, respectively. Id col.18 11.31-34.
B. Prior Art
U.S. Patent No. 4,094,647 (“Deutsch”) also discloses a method of detecting ligandantiligand binding pairs in order to determine the presence of a ligand (the analyte) in a biological fluid sample. In Deutsch, a test strip is prepared in which a reagent is immobilized in a downstream portion of the strip and the test solution is applied to the other end. The edge of the strip is
U.S. Patent No. 3,641,235 (“Weiss”) teaches a similar immunoassay method for visually detecting the presence of an analyte in biological fluid. In Weiss, the visual readout is an indicator that is either fixated in the reaction zone in the presence of the analyte or released in the presence of the analyte, in which case the release can be observed by the presence of the indicator material in the fluid front of the test solution moving forward on the strip. Weiss cols. 3-5.
U.S. Patent No. 3,466,241 (“Tom”) discloses another immunoassay method, in which one of the reagents comprises “a signal creating system.” Tom col.3 11.1-5, 11.47-49. Tom’s signal producing system includes “radioactive substances, enzymes and chromogenic substances....” Id. col.5 11.1-10.
C. Initial Examination
The examiner initially rejected all the claims in the application that resulted in the '484 patent as obvious under
The claims were amended, and on December 17, 1991, the '484 patent was granted. Subsequently, the '484 patent was assigned to Surmodics, Inc. (“Surmodics” or “patentee”), the real party at interest in the current proceedings, who exclusively licensed the patent to Abbott Laboratories (“Abbott”).
D. Abbott v. Syntron
On December 30, 1998, Abbott sued Syntron Bioresearch, Inc. (“Syntron”) for infringement of two patents, one of which was the '484 patent. Syntron counterclaimed that the patents were invalid, claiming, inter alia, that claims 22 and 23 of the '484 patent were invalid in light of Deutsch. On October 4, 2001, the jury returned a special verdict finding that the asserted claims of the patents-in-suit were not infringed and that Syntron had failed to prove by clear and convincing evidence that the claims were anticipated, obvious, or otherwise invalid. The district court entered judgment accordingly. Abbott Labs. v. Syntron Bioresearch, Inc., No. 98-CV-2359 (S.D.Cal. Oct. 12, 2001) (“Abbot Labs I ”). Abbott appealed, and Syn-tron cross-appealed to this court.
On appeal, we affirmed-in-part and remanded-in-part the judgment of noninfringement of the '484 patent and affirmed the judgment of validity on all asserted claims of the '484 patent.
Abbott Labs. v. Syntron Bioresearch, Inc.,
E. Reexamination
Following the appeal, Syntron filed a request for an ex parte reexamination of the '484 patent, claiming that there was a substantial new question of patentability.
See
The Board affirmed the examiner’s rejections.
In re Swanson,
No.2005-0725,
Surmodics filed this timely appeal, over which we have jurisdiction pursuant to
Surmodics objects to the rejection of claims 22-25 on two grounds. First, it argues that the Board erred in affirming the examiner’s determination that Weiss anticipated claims 22 and 23. Second, it argues that the reexamination of claims 22-25 on the basis of Deutsch was improper under
The PTO’s rejection based on Weiss did not include any claims not also rejected under Deutsch. As we conclude that neither the district court action nor the initial examination bars the PTO’s consideration of Deutsch in the reexamination proceedings, and the patentee does not challenge the rejection of claims 22-25 in light of Deutsch on the merits, we consider only whether Deutsch raised a substantial new question of patentability and do not reach the issue of whether the Board properly found claims 22 and 23 anticipated by Weiss.
II.
We review the Board’s legal conclusions including statutory interpretation de novo.
In re Am. Acad, of Sci Tech Ctr.,
A. The Reexamination Statute and the Amendment to
Any person may file a request for an ex parte reexamination of an issued patent based on prior art patents or printed publications.
The PTO, however, may only grant a reexamination request if it determines that “a substantial new question of patentability affecting any claim of the patent concerned is raised by the request.”
4
Within three months following the filing of a request for reexamination under the provisions ofsection 302 of this title, the Director will determine whether a substantial new question of patentability affecting any claim of the patent concerned is raised by the request, with or without consideration of other patents or printed publications.... The existence of a substantial new question of patent-ability is not precluded by the fact that a patent or printed publication was previously cited by or to the Office or considered by the Office.
We have not had the opportunity to evaluate the scope of the “substantial new question of patentability” requirement since the 2002 amendment. Thus, this appeal presents issues of first impression. In determining the scope of the substantial new question requirement under the amended statute, “[w]e begin, as always, with the language of the statute.”
Duncan v. Walker,
B. District Court Proceedings
The patentee first argues that the district court’s consideration of Deutsch in determining the validity of the '484 patent necessarily precludes the reference from raising a “new” question of patentability in subsequent reexamination proceedings. The district court and this court did consider the precise question at issue on reexamination: whether Deutsch satisfies the “flowing” limitation of the asserted claims and, thus, anticipates them. And both courts upheld the validity of the '484 patent in light of Deutsch. Nevertheless, the statutory language, legislative history, and different purposes underlying reexamination and federal court proceedings suggest that the determination of a substantial new question is unaffected by these court decisions.
The statute does not define what constitutes a “substantial new question of patentability.” However, the language added in the amended statute specifically discusses references “previously cited by or to the Office or considered by the Office,”
The focus on previous examinations rather than prior litigation follows from the fact that “reexamination[s are] conducted according to the procedures established for initial examination,”
In civil litigation, a challenger who attacks the validity of patent claims must overcome the presumption of validity with clear and convincing evidence that the patent is invalid.
In PTO examinations and reexaminations, the standard of proof — a preponderance of evidence — is substantially lower than in a civil case,
In re Caveney,
In
Ethieon,
we held that because of these differences between reexaminations and court proceedings, the PTO did not have authority to stay a patent reexamination proceeding pending the outcome of a case in a district court given the requirement in
We agree with the PTO’s current position.
Surmodics argues that this reading of the statute — allowing an executive agency to find patent claims invalid after an Article III court has upheld them validity— violates the constitutionally mandated separation of powers, and therefore must be avoided. We disagree. The Supreme Court has repeatedly held that “Congress cannot vest review of the decisions of Article III courts in officials of the Executive Branch.”
Plant v. SpendThrift Farm,
We, therefore, conclude the Board did not err in holding that the prior district court litigation did not prevent the Deutsch reference from raising a “substantial new question of patentability” under
C. Initial Examination
Surmodics also argues that Deutsch does not raise “a substantial new question of patentability” because Deutsch was considered by the PTO during the initial examination and relied on as a secondary reference for rejecting various dependent claims as obvious. Surmodics recognizes that the 2002 amendment to
The 2002 amendment removes the focus of the new question inquiry from whether the reference was previously considered, and returns it to whether the particular question of patentability presented by the reference in reexamination was previously evaluated by the PTO. As was true before the amendment, an “argument already decided by the Office, whether during the original examination or an earlier reexamination” cannot raise a new question of patentability. H.R.Rep. No. 96-1307(1), U.S.Code Cong. & Admin.News 1980, pp. 6460, 6466;
see also
H.R.Rep. No. 107-120, at 3 (explaining that the amendment did not diminish the “substantial new question requirement” and that “[t]he issue raised must be more than just questioning the judgment of the examiner.”). As we explained in
In re Recreative Technologies Corp.,
the substantial new question requirement “guard[s] against simply repeating the prior examination on the same issues and arguments” and bars “a second examination, on the identical ground that had previously been raised and overcome.”
As the legislative history clarifies, to decide whether a reference that was previously considered by the PTO creates a substantial new question of patentability, the PTO should evaluate the context in which the reference was previously considered and the scope of the prior consideration and determine whether the reference is now being considered for a substantially different purpose. See H.R.Rep. No. 107-120, at 3 (“The appropriate test to determine whether a ‘substantial new question of patentability’ exists should not merely look at the number of references or whether they were previously considered or cited but their combination in the appropriate context of a new light as it bears on the question of the validity of the patent.”); see also 147 Cong. Rec. H5359 (statement of Rep. Berman) (“Ideally, a reexamination could be requested based on prior art cited by an applicant that the examiner failed to adequately consider.... ”).
Determining the scope of an examiner’s previous consideration of a reference will generally require an analysis of the record of the prior proceedings to determine if and how the examiner used the
We agree with the Board that whether Deutsch anticipates claims 22-24 raises a substantial new question of patentability under the amended
In light of the extremely limited purpose for which the examiner considered Deutsch in the initial examination, the Board is correct that the issue of whether Deutsch anticipates the method disclosed in claims 22, 23, and 25 was a substantial new question of patentability, never before addressed by the PTO. 6
On appeal, Surmodics’ only argument for why the Board erred in affirming the rejection of claims 22, 23, and 25 as anticipated by Deutsch is the alleged lack
We also affirm the obviousness rejection of claim 24 in view of Deutsch and Tom. Surmodics has not argued the issue separately, but instead has stated that its appeal on this issue depends solely on whether Deutsch raises a substantial new question of patentability with regards to claims 22 and 23. See Appellant’s Br. 60 (“The patentability of claim 24 rises or falls with claims 22 and 23. The only question is as to Deutsch and that question is an old one addressed in a final court judgment and by the PTO in the original prosecution.”). Thus, in light of our affirmance of the rejection of claims 22 and 23, any argument for why • the rejection of claim 24 should nevertheless be reversed has been waived.
CONCLUSION
The Board did not err in finding that whether Deutsch anticipated claims 22, 23, and 25 of the '484 patent or made obvious claim 24 in combination with Tom raised substantial new questions of patentability sufficient to warrant reexamination. Accordingly, the Board’s decision affirming the examiner’s rejection of claims 22-25 is affirmed.
AFFIRMED
Notes
. Originally filed claim 9 claimed:
Method for the quantitative analysis of an analyte in a carrier liquid, characterized by the steps of:
providing a fluid-permeable solid medium defining a flow path and having predetermined number of successive, spaced reaction zones in the path of flow, said reaction zones having immobilized therein a reactant reactive with the analyte or an analyte derivative or both to result in the formation of a predetermined product; flowing said fluid along the flow path and sequentially through the spaced reaction zones; and
detecting the presence of analyte, analyte derivative, reactant or predetermined product in the reaction zones; the amount of analyte in the fluid being a function of the number of zones in which such detection occurs.
. The only other mention of Deutsch in the record provided is similar. Dependant claims 17 and 18 were rejected as obvious over Morison or Bauer et al in view of "any one of Ruhenstroth-Bauer et al, Brown et al and Deutsch et al.” Again the examiner explained, “it would be obvious to incorporate any reaction within reason in the apparatus of either Morison or Bauer et al, as see the immunoreactions of the secondary art.” Id.
. While the Board's statutory interpretation in a particular case is given no deference, deference may be owed to the PTO's interpretation of statutory provisions concerning "the conduct of proceedings in the Office,”
. The PTO may also instigate a reexamination proceeding on its own motion if it determines that prior art patents or printed publications raise a substantial new question of patentability.
. In contrast, an attempt to reopen a final federal court judgment of infringement on the basis of a reexamination finding of invalidity might raise constitutional problems.
. In reaching this holding, we do not rely on the fact, discussed by the Board, that claim 22 differed from the rejected claims in the initial patent. While the difference between rejected claims and the claims at issue during a reexamination may be relevant to whether there is a substantial new question of patentability, a change in the scope of a claim will not, in itself, make all questions of patentability of the revised claim "substantial new question[s].” As the limited scope of the examiner’s consideration of Deutsch is sufficient to find that anticipation by Deutsch raises a substantial new question of patentability, we need not consider what effect the change in scope of the claims would have had had Deutsch been more fully considered during the initial proceeding.