How is orphan drug exclusivity affected when the FDA-approved use for an orphan drug is arguably narrower than the treatment of the rare disease it was designated for?

By way of background, a sponsor can obtain orphan drug exclusivity when the FDA approves an application for a drug that has first been designated under 21 U.S.C. § 360bb of the Orphan Drug Act (ODA) for a “rare disease or condition.”  Id. § 360cc(a).  Except in any of three statutorily prescribed circumstances (§§ 360cc(b), (c)), the FDA cannot approve another application for the “same drug” for “the same disease or condition” for seven years after the first approval.

When a pharmaceutical company withdraws a product from the market, the basis for the withdrawal can affect whether a competitor can commercialize a generic version of that product. A generic cannot be approved if, in the FDA’s view, the product was withdrawn for “safety and effectiveness” reasons.

But how does the FDA reach that conclusion? A newly filed case may shed some light on the Agency’s decision-making process.