A Florida drug company at the heart of ongoing disputes over the price of life-saving drugs has doubled down, bringing a federal lawsuit against the FDA for the agency’s alleged end-run around the drug company’s commercial rights.

In a complaint filed in the federal court for the Southern District of Florida, Catalyst Pharmaceuticals says that the FDA had no right to award pediatric rights for Ruzurgi (amifampridine) to Jacobus Pharmaceuticals to treat Lambert-Eaton Myasthenic Syndrome, a rare, genetic disorder in which a patient’s autoimmune system attacks his or her own tissues.

Catalyst had won orphan status for its version of amifampridine, which it called Firdapse. But when it listed Firdapse’s price at $375,000 per year—previous versions had cost between $300 and $500 per month—it drew condemnation from patient advocates and political leaders, including Sen. Bernie Sanders (I-Vt.).

Firdapse won approval for treatment of adults with Lambert-Eaton and more than one commenter saw the FDA’s pediatric approval for Jacobus—a nonprofit group—as a way to diffuse the controversy by giving doctors a cheaper, off-label alternative.