For patents having a filing date of earlier than March 16, 2013, i.e., the date the America Invents Act is fully implemented, an issued patent can be challenged under the Inter Partes Review provisions of the AIA or “first to file” statute. Such patents are not subject to the Post Grant Review provisions since Post Grant Review only applies to patents having a filing date later than March 16, 2013. (See the following Post.)

In many ways, the Inter Partes Review procedure is similar to Post Grant Review. Both procedures allow a third party to challenge the validity of an issued patent. The third party does not have to wait for the patent owner to sue the third party for infringement in order that the third party can challenge the patent.

However, unlike Post Grant Review, the third party can only challenge the patent under §102 (novelty) or §103 (obviousness) grounds. The grounds of challenge must be based on patents and printed publications. It is not clear if documents establishing an invalidating prior sale would be considered a printed publication. This is important since documents pertaining to the prior sale may not be in the possession of third party at the time the initiating petition is filed. This question goes to the standard used by the Patent Trial and Appeals Board in determining whether to grant a petition.

As indicated, Inter Partes Review is initiated by petition filed with the Patent Trial and Appeals Board (PTAB). The petition must establish that there is a reasonable likelihood that the petitioner would prevail with respect to at least one of the challenged claims. Discovery is limited to depositions of witnesses submitting affidavits or declarations and what is otherwise necessary in the interest of justice. (An ambiguous standard-see 35 USC §316(a)(5).)

As with Post Grant Review, the patentee may file a preliminary response rebutting the allegations of the third party petition. The Director (USPTO) will determine whether to initiate the proceeding within 3 months after the petition is filed. (Obviously the patentee must be prompt in filing a rebuttal to the petition in view of the Director’s deadline for deciding whether to grant or deny the petition.)

If the petition is granted, the patentee may file a further response to the petition containing affidavits or declarations, additional factual evidence or expert opinions. See 35 USC §316(a)(8) and §326(a)(8).

Settlement is encouraged by the right of the patentee to cancel any challenged claim or, more importantly, propose a reasonable number of proposed claims for each challenged claim. See 35 USC § 316(d)(1) and § 326(d)(3). Further both the petitioner and patentee may jointly file motions to amend to advance settlement. See 35 USC § 316(d)(2) and § 326(d)(2).

Both parties are entitled to an oral hearing. See 35 USC § 316(a)(10) and §326(a)(10).

The PTAB must make a final determination within 1 year after petition granted (subject to one 6 month extension for good cause). The proceeding concludes with a certificate being issued that cancels unpatentable claims, confirms patentable claims and incorporates any new or amended claims that are patentable. Such new or amended claims are subject to intervening rights. See 35 USC §318(c) and §328(c).

In regard to the operation of intervening rights, first, it must be determined whether the claims at issue are “amended or new.” If so, analysis must be made under 35 U.S.C. § 252, and the statutory requirement that intervening rights only be available for claims that undergo a “substantive change.” The language of 35 U.S.C. § 252 makes clear that absolute intervening rights extend only to anything made, purchased, sold, or used “before the grant of a reissue” patent. This is assumed to be also applicable to patent claims subject of a written decision of the PTAB and the certificate issued by the Director. In other words, the doctrine of absolute intervening rights “covers products already made at the time of reissue.” These rights are considered “absolute” because of the statutory command that a reissued patent “shall not” limit the rights of an accused infringer that practices the original claims before reissuance of the patent. Therefore the doctrine of intervening rights excuses infringing activity occurring before PTAB decision approving substantively revised claims. The statute also limits absolute intervening rights to a “specific thing” existing before the patent reissues.