Recently, the Eleventh Circuit sided with Florida-based Catalyst Pharmaceuticals Inc., holding that the U.S. Food and Drug Administration’s interpretation of the Orphan Drug Act is contrary to the plain language of the statute. Catalyst Pharm., Inc. v. Becerra. The court found that the FDA unlawfully infringed on an exclusivity period it awarded to Catalyst for a drug that treats a rare autoimmune disease when the agency granted exclusivity for pediatric uses to another drugmaker.

In 1983, Congress enacted the Orphan Drug Act, which incentivizes pharmaceutical companies to develop “orphan drugs”—drugs for rare diseases or conditions that affect such a small portion of the population that there otherwise would be no financial motivation to research and develop treatment. Under this straightforward framework, a pharmaceutical manufacturer may request the FDA to designate a drug as an orphan drug. Like any new drug, the orphan drug must be approved by the FDA before it can be brought to market, and the manufacturer can only market the drug for the specified indications. Upon designation and FDA approval, the manufacturer of the orphan drug is then granted market exclusivity for a seven-year period, during which the FDA is not permitted to approve another application for “the same drug for the same disease or condition.” 21 U.S.C. § 360cc(a).

In 2018, the FDA approved, under the Orphan Drug Act, the use of Catalyst’s drug Firdapse to treat Lambert-Eaton Myasthenic Syndrome (“LEMS”), a rare autoimmune disease that has fewer than 1,300 diagnosed cases in the United States. The following year, the FDA approved rival Jacobus Pharmaceutical Company Inc.’s drug Ruzurgi for the treatment of LEMS in patients 6 to 17 years old. Although both drugs feature the same active ingredient, the agency concluded that approving Ruzurgi did not violate Catalyst’s exclusivity because its approval for pediatric patient constituted a different “indication or use” and thus fell outside the scope of the orphan drug exclusivity applicable to Firdapse.

The district court focused on the statutory phrase “same disease or condition,” finding it unclear whether it refers to the use for which the drug is approved—LEMS for adults—or the disease or condition for which it received its orphan drug designation—LEMS for all patients. Finding the phrase to be ambiguous, the district court then held that the FDA’s “use or indications” interpretation was reasonable. The Eleventh Circuit disagreed, finding the phrase unambiguous. The panel noted that the word “same” is being used in the sense of “being the one under discussion or already referred to,” and that the only “disease or condition” referred to is the “rare disease or condition” for which the drug was designated under the Orphan Drug Act. Thus, the Court concluded that because orphan drug exclusivity provisions preclude the FDA from approving another application for “the same drug for the same disease or condition,” the orphan drug exclusivity applies to the entire designated disease or condition rather than the “indication or use.”

This decision suggests that orphan drug exclusivity may now extend significantly beyond than the approved indication or use.