MPEP 2308.03
Estoppel Within the Office

This is the Ninth Edition of the MPEP, Revision 08.2017, Last Revised in January 2018

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2308.03    Estoppel Within the Office [R-08.2017]

If a party loses on an issue, it may not re-litigate the issue before the examiner or in a subsequent Board proceeding. The time for the party to make all pertinent arguments is during the interference, unless the Board expressly prevented the party from litigating the issue during the interference.

There are two main types of interference estoppel. First, a losing party is barred on the merits from seeking a claim that would have been anticipated or rendered obvious by the subject matter of the lost count. See In re Deckler, 977 F.2d 1449, 24 USPQ2d 1448 (Fed. Cir. 1992); and Ex parte Tytgat, 225 USPQ 907 (Bd. Pat. App. & Inter. 1985). Second, a losing party is procedurally barred from seeking from the examiner relief that could have been--but was not--sought in the interference. See 37 CFR 41.127(a)(1); and Ex parte Kimura, 55 USPQ2d 1537 (Bd. Pat. App. & Inter. 2000) (reissue applicant estopped to claim compound when patentability of that compound could have been put in issue in interference where opponent’s application also described compound).

The examiner should consult with an Interference Practice Specialist (IPS) before allowing a claim to a losing party that was added or amended during post-interference examination.

Example 1

The applicant lost on priority for a count drawn to subject matter X. The Board’s judgment automatically disposed of all of the applicant’s claims corresponding to the count. The applicant files a continuing application with a claim to subject matter X. The claim must be rejected as estopped on the merits by the applicant’s loss in the interference.

Example 2

Same facts as Example 1 except the applicant files a continuing application with a claim generic to subject matter X. Since the generic claim encompasses subject matter lost in the interference, the generic claim must be rejected as estopped on the merits by the loss in the interference.

Example 3

Same facts as Example 1 except the applicant files a continuing application with a claim to subject matter that would have been obvious in view of subject matter X. The claim must be rejected as estopped on the merits by the applicant’s loss in the interference, but the examiner must demonstrate why the claim would have been obvious if subject matter X is assumed to be prior art.

Example 4

Same facts as Example 1 except the applicant files a continuing application with a claim identical to a claim that corresponded to the count of the interference. The applicant also files a showing of why the claim should not have corresponded to the count. The claim should be rejected as procedurally estopped. Whether the showing is adequate or not, it is too late. The time to make the showing was during the interference.

Example 5

Same facts as Example 4 except that during the interference the applicant timely requested, but was not permitted, to show the claim did not correspond to the count. The examiner may determine in light of the new showing whether the lost count would have anticipated or rendered obvious the subject matter of the claim. The procedural estoppel does not apply if, through no fault of the applicant, the Board prevented the applicant from seeking relief during the interference.

Example 6

The applicant’s claim 1 was held unpatentable during the interference. The applicant could have moved, but did not move, to amend the claim. The applicant files a continuing application with an amended claim 1. If the subject matter of the amended claim would have been anticipated or obvious in view of a count of the interference, it must be rejected as procedurally estopped. Whether the amendment is sufficient to overcome the ground for unpatentability or not, the time to have amended the claim was during the interference.

Example 7

Same situation as Example 6 except the applicant did move to amend the claim, but the motion was denied. The result is the same as in Example 6. If the subject matter of the amended claim would have been anticipated or obvious in view of a count of the interference, it must be rejected as procedurally estopped. The applicant’s lack of success on the motion does not prevent the estoppel from applying to the claim.

Example 8

Same facts as Example 6 except the applicant filed a late request during the interference to amend the claim to overcome the basis for unpatentability. The request was denied as untimely. The claim must be rejected as procedurally estopped. Even though the applicant was not permitted to amend the claim during the interference, the estoppel still applies because the applicant’s inability to obtain relief in the interference was the result of the applicant’s failure to seek timely relief.