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2286 Ex Parte Reexamination and Litigation Proceedings [R-10.2019]

37 CFR 1.565  Concurrent office proceedings which include an ex parte reexamination proceeding.


  • (b) If a patent in the process of ex parte reexamination is or becomes involved in litigation, the Director shall determine whether or not to suspend the reexamination. See § 1.987 for inter partes reexamination proceedings.


35 U.S.C. 302 permits a request for ex parte reexamination to be filed “at any time.” Requests for ex parte reexamination are frequently filed where the patent for which reexamination is requested is involved in concurrent litigation. The guidelines set forth below will generally govern Office handling of ex parte reexamination requests where there is concurrent litigation in the federal courts.


Where a request for ex parte reexamination indicates (A) that it is filed as a result of an order by a court or an agreement by parties to litigation which agreement is sanctioned by a court, or (B) that litigation is stayed for the filing of a reexamination request, all aspects of the proceeding will be expedited to the extent possible. If reexamination is ordered, the examination following the statement by the patent owner under 37 CFR 1.530 and the reply by the requester under 37 CFR 1.535 will be expedited to the extent possible.


If a federal court decision on the merits of a patent is known to the examiner at the time the determination on the request for ex parte reexamination is made, the following guidelines will be followed by the examiner, whether or not the person who filed the request was a party to the litigation. When the initial question as to whether the prior art raises a substantial new question of patentability as to a patent claim is under consideration, the existence of a final court decision of claim validity in view of the same or different prior art does not necessarily mean that no new question is present. This is true because of the different standards of proof employed by the district courts and the Office and different standards of claim interpretation used in reexamination proceedings involving unexpired patent claims. See for example In re Zletz, 893 F.2d 319, 322, 13 USPQ2d 1320, 1322 (Fed. Cir. 1989) (manner of claim interpretation that is used by courts in litigation is not the manner of claim interpretation that is applicable during prosecution of a pending application before the PTO) and In re Etter, 756 F.2d 852, 225 USPQ 1 (Fed. Cir. 1985) (the 35 U.S.C. 282 presumption of patent validity does not apply in reexamination proceedings). Thus, while the Office may accord deference to factual findings made by the court, the determination of whether a substantial new question of patentability exists will be made independently of the court’s validity determination as it is not controlling on the Office. See In re Swanson et al., 540 F.3d 1368, 1378, 88 USPQ2d 1196, 1203 (Fed. Cir. 2008), where the Federal Circuit approved of the Office’s interpretation in MPEP § 2242. A non-final holding of claim invalidity or unenforceability will not be controlling on the question of whether a substantial new question of patentability is present. A final holding of claim invalidity or unenforceability (after all appeals), however, is controlling on the Office. In such cases, a substantial new question of patentability would not be present as to the claims held invalid or unenforceable because such claims no longer exist in the patent. See Ethicon v.Quigg, 849 F.2d 1422, 7 USPQ2d 1152 (Fed. Cir. 1988).

Note the following Federal Circuit decisions involving reexamination proceedings where the court affirmed the Office’s rejections even though parallel district court proceedings held that the claims at issue had not been proven invalid and were infringed. In re Trans Texas Holdings Corp., 498 F.3d 1290, 83 USPQ2d 1835 (Fed. Cir. 2007), In re Translogic Technology, Inc., 504 F.3d 1249, 84 USPQ2d 1929 (Fed. Cir. 2007), In re Swanson et al., 540 F.3d 1368, 88 USPQ2d 1196 (Fed. Cir. 2008) and In re Baxter International Inc., 678 F.3d 1357, 102 USPQ2d 1925 (Fed. Cir. 2012).

In Trans Texas, the patent being reexamined was subject to an infringement suit, in which the district court had issued its claim construction ruling (in a district court opinion) as to the definition of a term. The parties ultimately reached a settlement before trial, and the district court issued an “Order of Dismissal with Prejudice.” The patent owner relied on that district court claim construction ruling in a reexamination proceeding, and argued that the Office was bound by that district court claim construction ruling, under the doctrine of issue preclusion. The Federal Circuit stated that issue preclusion could not be applied against the Office based on a district court holding in an infringement proceeding, because the Office was not a party to that earlier infringement proceeding and the Office applied different standards and burden of proof.

In Translogic, a district court infringement suit proceeded in parallel with a reexamination proceeding. The district court held that the claims at issue had not been proven invalid, while in the reexamination proceeding, the examiner found the same claims to be unpatentable as obvious. The examiner’s rejection was affirmed by the Board. The defendant (the alleged infringer) of the infringement suit appealed the district court decision to the Federal Circuit, while the patent owner appealed the Board’s decision to the Federal Circuit. The Federal Circuit consolidated the appeals, and addressed the patent owner’s reexamination appeal from the Board. The Federal Circuit affirmed the examiner’s conclusion of obviousness by relying upon and providing an extensive discussion of KSR International Co. v. Teleflex Inc., 550 U.S. 398, 82 USPQ2d 1385 (2007). Since the claims were found to be unpatentable, the inconsistent district court decision was vacated and remanded.

Note also In re Swanson et al., 540 F.3d 1368, 88 USPQ 2d 1196 (Fed. Cir. 2008) where the Federal Circuit held that the prior federal court judgment holding that the claims were not proven invalid over a specific prior art reference (in Abbott Labs. v. Syntron Bioreseach, Inc., 334 F.3d 1343, 67 USPQ2d 1337 (Fed. Cir. 2003)), did not preclude the Office’s finding that a substantial new question of patentability existed as to the same claims based on the same prior art reference applied in the same manner in the subsequent ex parte reexamination proceeding, and did not preclude the Office’s finding that the patent claims were unpatentable.

Finally, see In re Baxter International Inc., 678 F.3d 1357, 102 USPQ2d 1925 (Fed. Cir. 2012)(patent reexamination should take notice of a court decision but the Office need not come to the same conclusion as the court).

Any determination on a request for reexamination which the examiner makes after a federal court decision must be reviewed by the Central Reexamination Unit (CRU) Supervisory Patent Reexamination Specialist (SPRS) to ensure that it conforms to the current Office litigation policy and guidelines. See MPEP § 2240.

For a discussion of the policy in specific situations where a federal court decision has been issued, see MPEP § 2242.


In view of the statutory mandate to make the determination on the request within 3 months, the determination on the request based on the record before the examiner will be made without awaiting a decision by the federal court. It is not realistic to attempt to determine what issues will be treated by the federal court prior to the court decision. Accordingly, the determination on the request will be made without considering the issues allegedly before the court. If an ex parte reexamination is ordered, the reexamination will continue until the Office becomes aware that a court decision has issued. At such time, the request will be reviewed in accordance with the guidelines set forth below. The patent owner is required by 37 CFR 1.565(a) to call the attention of the Office to any prior or concurrent proceeding in which the patent is involved or was involved. Thus, the patent owner has an obligation to promptly notify the Office that a decision has been issued in the federal court.


Pursuant to 37 CFR 1.565(a), the patent owner in an ex parte reexamination proceeding must promptly notify the Office of any federal court decision involving the patent. Where the reexamination proceeding is currently pending and the court decision issues, or the Office becomes aware of a court decision relating to a pending reexamination proceeding, the order to reexamine is reviewed to see if a substantial new question of patentability is still present. If no substantial new question of patentability is still present, the reexamination is terminated by the CRU or TC Director.

A non-final federal court decision concerning a patent under reexamination shall have no binding effect on a reexamination proceeding.

The issuance of a final federal court decision holding that a claim has not been proven to be invalid during an ex parte reexamination also will have no binding effect on the examination of the reexamination. This is because, as the court stated, in Ethicon v.Quigg, 849 F.2d 1422, 1428, 7 USPQ2d 1152, 1157 (Fed. Cir. 1988) that the Office is not bound by a court’s holding that a patent is "not invalid", and therefore, should continue the reexamination. The court notes that district courts and the Office use different standards of claim construction and different standards of proof in evaluating patentability and validity, and thus, on the same evidence, could quite correctly come to different conclusions. Specifically, invalidity in a district court must be shown by “clear and convincing” evidence, whereas in the Office, it is sufficient to show unpatentability by a “preponderance of evidence.” Since the “clear and convincing” standard is more difficult to satisfy than the “preponderance” standard, deference will ordinarily be accorded to the factual findings of the court where the evidence before the Office and the court is the same. If sufficient reasons are present, however, claims held as "not invalid" by the court may still be rejected in reexamination.

On the other hand, a final federal court holding of invalidity or unenforceability (after all appeals), is binding on the Office. Upon the issuance of a final holding of invalidity or unenforceability, the claims being examined which are held invalid or unenforceable are no longer in force, and therefore, will be withdrawn from consideration in the reexamination. The reexamination will continue as to any remaining claims being examined. Thus, the reexamination will continue if any original, new, or amended claim being examined that was not found invalid or unenforceable by the court. If all of the claims being examined in the reexamination proceeding are finally held invalid or unenforceable, the reexamination will be vacated by the CRU or TC Director if the decision was rendered prior to the order, or terminated by the CRU or TC Director as no longer containing a substantial new question of patentability if the decision was rendered subsequent to the order, and the reexamination will be concluded. If all claims being examined were not held invalid (or unenforceable) (i.e., some claims still remain), a substantial new question of patentability may still exist as to the remaining claims. In such a situation, the remaining claims would be examined; and, as to the claims held invalid or unenforceable, form paragraph 22.20 should be used at the beginning of the Office action.

¶ 22.20 Claims Held Invalid By Court, No Longer Being Reexamined

Claims [1] of the [2] patent are not being reexamined in view of the final decision of [3]. Claim(s) [1] was/were held invalid/unenforceable by the [4].

Examiner Note:

  • 1. In bracket 1, insert the claim(s) held invalid.
  • 2. In bracket 2, insert the patentee (e.g., Rosenthal, J. Doe et al).
  • 3. In bracket 3, insert the decision (e.g., ABC Corp. v. Smith, 888 F. 3d 88, 999 USPQ2d 99 (Fed. Cir. 1999) or XYZ Corp. v. Jones, 888 F. Supp. 2d 88, 999 USPQ2d 1024 (N.D. Cal. 1999)).
  • 4. In bracket 4, insert the name of the court (e.g., the Court of Appeals for the Federal Circuit, or the Federal District Court).

In order to ensure that the Office is aware of prior or concurrent litigation, the examiner is responsible for conducting a reasonable investigation for evidence as to whether the patent for which ex parte reexamination is requested has been or is involved in litigation. The investigation will include a review of the reexamination file, the patent file, and the results of the litigation computer search.

If the examiner discovers, at any time during the reexamination proceeding, that there is litigation or that there has been a federal court decision on the patent, the fact will be brought to the attention of the CRU SPRS or Technology Center (TC) Quality Assurance Specialist (QAS) prior to any further action by the examiner. The CRU SPRS or TC QAS must review any action taken by the examiner in such circumstances to ensure current Office litigation policy is being followed.


Once a federal court has ruled upon the merits of a patent and an ex parte reexamination is still appropriate under the guidelines set forth above, the federal court decision will be considered controlling and will be followed as to claims finally held to be invalid by the court.

2286.01 Reexamination and Inter Partes Review Proceedings, Post-Grant Review, and Covered Business Method Patent Review [R-07.2015]

The Leahy-Smith America Invents Act amended 35 U.S.C. 315(d) and added 35 U.S.C. 325(d) to provide that, during the pendency of an inter partes review, post grant review or covered business method review ("PTAB Review Proceeding"), if another proceeding (e.g., an ex parte reexamination proceeding) or matter involving the patent is before the Office, the Director may determine the manner in which the PTAB Review Proceeding and the other proceeding or matter may proceed, including providing for stay, transfer, consolidation, or termination of such matter or proceeding. If an examiner becomes aware of a PTAB Review Proceeding for the same patent that is being reexamined, the ex parte reexamination proceeding must be referred to the examiner’s SPRS. The SPRS will coordinate with the PTAB before taking any action on the reexamination proceeding.

The existence of a PTAB Review Proceeding does not change the fact that any reexamination request must, by statute, be decided (a grant or a denial) within three months of its filing date.



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Last Modified: 02/16/2023 12:58:23