In Mayo Foundation v. Iancu, in a split decision, the Fed. Cir. affirmed the PTO’s PTA calculation based on their interpretation of B Delay of “any time consumed by continued examination of the application requested by the applicant under section 132(b).  In response to a final rejection, Mayo filed an RCE which resulted in a declaration of interference, terminated in favor of Mayo, wherein the Examiner re-opened prosecution, issuing an OTDP rejection which Mayo overcame, resulting with the mailing of a notice of allowance. Mayo challenged the PTO’s PTA calculation of 621 days, with no B delay, arguing that RCE time ended with the declaration of interference because the declaration required at least one claim being “deemed allowable” and the examiner’s reopening of prosecution was not “requested” by applicants.  The Fed. Cir. found PTO regulations contemplate that the Board may recommend further action by the examiner and thus, as a whole did not indicate a declaration of interference to be tantamount to a notice of allowance.  The Fed. Cir. was not persuaded by Mayo’s argument that the new issues were raised in reopening prosecution, which were outside of the issues raised in the RCE.

In her dissent, Judge Newman found post-interference examination to be examination delay due to PTO procedure and the PTO’s interpretation to be contrary to the plain meaning of the statute affording diligent applicants at least a 17-year term, when a patent is not granted within three years.