President Obama has signed into law technical revisions to the Leahy-Smith America Invents Act (AIA). The AIA, which was enacted on 16 September 2011, makes significant changes to the US patent system, including those outlined here and here.

The revisions comprise straightforward clerical corrections but also substantive changes which include in particular elimination of “dead zone” periods, within which patents were not immediately challengeable at the United States Patent and Trademark Office (USPTO) under new post-grant mechanisms introduced by the AIA, and clarification as to how patent term adjustment is to be calculated for patents granted on US national phases of international patent (PCT) applications.

Elimination of Post-Grant Dead Zones

A party wishing to challenge a patent at the United States Patent and Trademark Office can do so via either of two alternative forms of “review”, namely Post-Grant Review and Inter Partes Review. These forms of review, which should generally be faster and cheaper than litigation (and which are discussed here under the heading Changes to challenging patents at the United States Patent and Trademark Office), were implemented under the AIA on 16 September 2012, to replace the inter partes reexamination procedure.

Post-Grant Review can only be sought within nine months following issuance of the patent but is presently only available for business method patents; it will be available for other (non-business method) patents only if they have an effective filing date of 16 March 2013 or later.

Inter Partes Review can be sought in respect of a patent regardless of its date, but originally could only be initiated nine months or more after the patent is granted (or any post-grant review proceeding in respect of it has concluded), with the consequence that neither form of review was immediately available to prospective challengers of (non business method) patents that were granted less than nine months ago, such patents thus having fallen within a "dead zone".

As a result of the revisions, the nine-month waiting period (commencing at grant) for initiating inter partes review has been removed; inter partes review can now be requested as of when the patent is granted.

AIA Patent Term Adjustment Provisions Clarified

US statute provides for patent term adjustment (PTA) to compensate patent owners where there have been excessive delays on the part of the USPTO in prosecution of their patent applications. PTA can be awarded in respect of various delays, including where a period of time which has elapsed since the filing date of the patent application exceeds a certain amount. The AIA introduces new provisions regarding calculation of PTA for such delays but there has been uncertainty as to the interpretation of those provisions where the patent application is the US national phase of a PCT application. The "filing date" of such an application is generally the date of "commencement of the national stage", which is 30 months from the earliest priority date of the PCT application (even if the national phase is initiated before that date), in the absence of an express request by the applicant that it be otherwise. The original wording of the new provisions suggested the "filing date" for the purposes of calculating PTA could be the date of filing of the PCT application, which is often 18 months earlier than date of commencement of the US national stage. The revisions confirm that it is the "30-month date" which constitutes the "filing date" for the purposes of calculating PTA.

Are There More AIA Revisions to Come?

In a speech summarising the now-implemented revisions, Congressman Lamar Smith, who co-sponsored the Bills for both the AIA and the revisions, indicated that further revisions may be introduced.