Under what conditions will OOPD designate an orphan drug and recognize orphan drug exclusivity for a new formulation of a drug that is otherwise the same drug as an already approved drug for the same rare disease or condition?

The public policy objective of the Orphan Drug Act is to stimulate innovation in developing treatments for patients with rare diseases and conditions and to foster the prompt availability of therapeutically superior drugs. Accordingly, the orphan drug regulations attempt to ensure that orphan drug exclusivity approval does not preclude significant improvements in treating rare diseases.
OOPD may grant orphan drug designation to a drug that is otherwise the same drug as a drug already approved in the U.S. for the same rare disease or condition only if the sponsor can present a plausible hypothesis that its drug may be “clinically superior” to the previously approved drug. Clinical superiority may be established by means of greater effectiveness, greater safety in a substantial portion of the target populations, or in unusual cases a major contribution to patient care (MC-to-PC).
Further, if orphan drug designation is granted, and if the drug receives marketing approval for the designated use, in order for the drug to receive orphan drug exclusive approval for this use, the sponsor must demonstrate that the drug is actually clinically superior to any previously approved same drug for the same use.
Any claim for clinical superiority could require a head-to-head trial.