Catalyst Pharmaceuticals, Inc. v. Xavier Becerra, 14 F.4th 1299

The Orphan Drug Act grants a seven-year market exclusivity to the sponsor of an FDA-approved orphan drug designated under 21 U.S.C. § 360bb for a "rare disease or condition."
Catalyst developed Firdapse (amifampridine phosphate); FDA designated it for LEMS and approved it for treatment of LEMS in adults on November 28, 2018, triggering exclusivity through November 28, 2025.
Jacobus developed Ruzurgi (amifampridine); its NDA was administratively divided into adult and pediatric components, and FDA approved Ruzurgi on May 6, 2019 for pediatric patients (ages 6 to <17) only.
The parties agree Firdapse and Ruzurgi are the "same drug" and LEMS is a single disease; Catalyst sued under the APA arguing the FDA violated § 360cc by approving Ruzurgi during Catalyst’s exclusivity.
The district court found the statutory phrase "same disease or condition" ambiguous, deferred to the FDA under Chevron, and granted summary judgment to defendants; Catalyst appealed.
The Eleventh Circuit reverses: it holds the phrase unambiguous (referring back to the § 360bb designation), finds FDA approval unlawful because no statutory exceptions applied, and directs entry of summary judgment for Catalyst.

Issue	Plaintiff's Argument	Defendant's Argument	Held
Meaning of "same disease or condition" in 21 U.S.C. § 360cc	"Same" unambiguously refers to the "rare disease or condition" designated under § 360bb (i.e., LEMS as designated), so exclusivity bars approval of the same drug for that disease during the 7-year period	Phrase is ambiguous; FDA reasonably interprets it to mean the approved "use/indication" under § 355 (so a pediatric-only approval does not infringe an adult approval)	Phrase is not ambiguous; it refers back to the § 360bb designation (disease-specific). Chevron deference inapplicable; FDA approval of Ruzurgi for LEMS during Catalyst’s exclusivity was unlawful.
FDCA labeling claim (false/misleading labeling)	Ruzurgi’s label (approved only for pediatric patients) is misleading as to adult use and violates FDCA labeling rules	FDA interpretation of its labeling rules is reasonable; no basis to set aside approval	Court did not reach merits because statutory exclusivity disposition resolved the case; district court’s favorable ruling to defendants on labeling was not addressed on appeal.

Chevron U.S.A., Inc. v. Natural Resources Defense Council, Inc., 467 U.S. 837 (establishes two-step agency deference framework)
Spectrum Pharmaceuticals, Inc. v. Burwell, 824 F.3d 1062 (D.C. Cir. 2016) (discusses § 360cc exclusivity in off-label/use context)
Sigma-Tau Pharmaceuticals, Inc. v. Schwetz, 288 F.3d 141 (4th Cir. 2002) (holds Orphan Drug Act exclusivity is disease-specific, not drug-for-all-uses)
Polycarpe v. E&S Landscaping Serv., Inc., 616 F.3d 1217 (11th Cir. 2010) (interpret statutory words by ordinary meaning in context)
Utility Air Regulatory Group v. EPA, 573 U.S. 302 (2014) (interpretation must account for specific and broader statutory context)