After providing notice in the form of a letter (that, for a drug approved under section
355 of this title, references a declined written request under section
355a of this title for a labeled indication which written request is not referred under section
355a
(n)(1)(A) of this title to the Foundation of the National Institutes of Health for the pediatric studies), the Secretary may (by order in the form of a letter) require the sponsor or holder of an approved application for a drug under section
355 of this title or the holder of a license for a biological product under section
262 of title
42 to submit by a specified date the assessments described in subsection (a)(2), if the Secretary finds that—