21 C.F.R. § 60.34 – FDA action on petitions.

(a) Within 90 days after FDA receives a petition filed under § 60.30(a), the agency will either deny the petition under paragraph (b) or (c) of this section or investigate and determine under § 60.36 whether the applicant acted with due diligence during the regulatory review period. FDA will publish its due diligence determination in the Federal Register, notify PTO of the due diligence determination in writing, and send copies of the notice to PTO, the applicant, and the petitioner.
(b) FDA may deny a due diligence petition without considering the merits of the petition if:
1. (1) The petition is not filed in accordance with § 60.30;
2. (2) The petition is not filed in accordance with § 10.20;
3. (3) The petition does not contain the information required by § 10.30;
4. (4) The petition fails to contain information or allegations upon which it may reasonably be determined that the applicant did not act with due diligence during the applicable regulatory review period; or
5. (5) The petition fails to allege a sufficient total amount of time during which the applicant did not exercise due diligence such that, even if the petition were granted, the petition would not affect the maximum patent extension the applicant sought in the application.