(3) Withdrawal The Secretary may not withdraw a designation granted under this section on the basis of the criteria under subsection (e) no longer applying because of the subsequent clearance or approval of any other product. (d) Expedited development and priority review Guidance (1) Content Not later than December 31, 2021, the Secretary shall issue guidance on the implementation of this section. Such guidance shall— (A) set forth the process by which a person may seek a designation under subsection (c)