[PUBLISH]

IN THE UNITED STATES COURT OF APPEALS

FOR THE ELEVENTH CIRCUIT ________________________

No. 20-13922 ________________________

D.C. Docket No. 1:19-cv-22425-BB

CATALYST PHARMACEUTICALS, INC.,

Plaintiff - Appellant, versus XAVIER BECERRA, Secretary of Health and Human Services, U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES, JANET WOODCOCK, Acting Commissioner of the Food and Drug Administration, U.S. FOOD AND DRUG ADMINISTRATION,

Defendants – Appellees, JACOBUS PHARMACEUTICAL COMPANY, INC.,

Intervenor-Defendant – Appellee.

________________________

Appeal from the United States District Court for the Southern District of Florida ________________________

(September 30, 2021) USCA11 Case: 20-13922 Date Filed: 09/30/2021 Page: 2 of 27

Before LAGOA, ANDERSON, and MARCUS, Circuit Judges. LAGOA, Circuit Judge:

This appeal asks us to determine whether the statutory phrase “same disease or condition” contained in the Orphan Drug Act, see 21 U.S.C. § 360cc, is ambiguous. It is not. By finding this statutory phrase ambiguous and then deferring to the U.S. Food and Drug Administration’s interpretation of it, the district court erred. We therefore reverse the district court’s grant of summary judgment in favor of the Defendants 1 and Jacobus, and remand with instructions to grant summary judgment in favor of Catalyst. I. FACTUAL AND PROCEDURAL HISTORY

A. The Orphan Drug Act

In 1983, Congress enacted the Orphan Drug Act, thereby amending the Federal Food, Drug, and Cosmetic Act (“FDCA”). See Pub. L. 97-414, 96 Stat. 2049 (codified as amended at 21 U.S.C. §§ 360aa–360ee). The Orphan Drug Act

1 Catalyst named Alex Azar, Secretary of Health and Human Services; Norman Sharpless, Acting Commissioner of the FDA; the U.S. Department of Health and Human Services; and the U.S. Food and Drug Administration as the Defendants in its Complaint. During the pendency of this case, the administration changed, and Secretary Azar and Acting Commissioner Sharpless resigned their positions. We therefore have substituted as defendants-appellees the proper individuals in their official capacity. See Fed. R. Civ. P. 25(d) (“An action does not abate when a public officer who is a party in an official capacity dies, resigns, or otherwise ceases to hold office while the action is pending. The officer’s successor is automatically substituted as a party. Later proceedings should be in the substituted party’s name, but any misnomer not affecting the parties’ substantial rights must be disregarded. The court may order substitution at any time, but the absence of such an order does not affect the substitution.”).

2 USCA11 Case: 20-13922 Date Filed: 09/30/2021 Page: 3 of 27

incentivizes pharmaceutical companies to develop “orphan drugs”—drugs for rare diseases that affect such a small portion of the population that there otherwise would be no financial incentive to research and develop treatments. One such incentive is to grant market exclusivity to the manufacturer of an FDA-approved orphan drug for a seven-year period. The framework established by the Orphan Drug Act is fairly straightforward: designation as an orphan drug followed by FDA approval results in market exclusivity. Each of these steps is governed by a separate part of the Orphan Drug Act.

1. Designation

Pursuant to 21 U.S.C. § 360bb(a)(1),