21 C.F.R. § 316.29 : Food and Drugs — FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES — DRUGS FOR HUMAN USE — ORPHAN DRUGS — DESIGNATION OF AN ORPHAN DRUG — Revocation of orphan-drug designation

(a) FDA may revoke orphan-drug designation for any drug if the agency finds that:
(1) The request for designation contained an untrue statement of material fact; or
(2) The request for designation omitted material information required by this part; or
(3) FDA subsequently finds that the drug in fact had not been eligible for orphan-drug designation at the time of submission of the request therefor.
(b) For an approved drug, revocation of orphan-drug designation also suspends or withdraws the sponsor's exclusive marketing rights for the drug but not the approval of the drug's marketing application.
(c) Where a drug has been designated as an orphan drug because the prevalence of a disease or condition (or, in the case of vaccines, diagnostic drugs, or preventive drugs, the target population) is under 200,000 in the United States at the time of designation, its designation will not be revoked on the ground that the prevalence of the disease or condition (or the target population) becomes more than 200,000 persons.
(d) If FDA revokes orphan-drug designation, FDA will publicize that the drug is no longer designated in accordance with § 316.28(e).

21 C.F.R. § 316.29

57 FR 62085, 12/29/1992, as amended at 78 FR 35134, 6/12/2013