A Delaware federal judge said he might ask Mallinckrodt Pharmaceuticals to choose between getting a competitor's inhaled nitric oxide treatment enjoined, or receiving the entire $9.5 million a jury determined it's owed for infringement.

U.S. District Judge Richard G. Andrews' memorandum from Tuesday said the case falls into an awkward spot, as Mallinckrodt is fighting a generic that Airgas Therapeutics released mid-litigation. A pre-launch suit over generic drugs aims for an injunction, while post-launch would focus on damages.

"It seems to me that the issue of injunctive relief is interrelated with the issue of the lump sum damages award for the life of the patents," Judge Andrews wrote in a new memorandum. "On the surface, it seems like double-counting. Plaintiffs may have to make a choice between all the awarded damages and an injunction. I do not decide that today."

A Delaware federal jury in September held that French industrial gas company Airgas willfully infringed three of Mallinckrodt's patents through its version of Mallinckrodt's INOMax, which is most commonly used for newborns and children with hypoxic respiratory failure. The jury also refused to invalidate the patents.

Judge Andrews issued the memorandum alongside his judgment on Tuesday, where he split from normal generic drug litigation practice by not issuing a final judgment with an injunction. The litigation is largely referred to by the name of an application for a generic drug: an abbreviated new drug application.

"I think I have always entered an injunction in the final judgment, but the next step after entering the final judgment in an ANDA case is an appeal, whereas in this hybrid case, the next step is going to be motions," Judge Andrews said. "Thus, I think it makes sense to hear the motions before entering an injunction."

Mallinckrodt sued Airgas in late December 2022, asking the court to stop the U.S. Food and Drug Administration from approving the generic, called Ulspira, until its patents expired. But during Mallinckrodt's attempt to stop Airgas, Airgas received FDA approval and went to market without the litigation decided — referred to as an at-risk launch.

Mallinckrodt had requested a preliminary injunction soon after the FDA approval in 2023, and Judge Andrews denied it in February 2025.

Representatives for Mallinckrodt and Airgas didn't immediately respond to requests for comment Wednesday.

The patents-in-suit are U.S. Patent Nos. 9,919,118; 9,279,794; and 8,776,794.

Mallinckrodt is represented by Frederick L. Cottrell III, Kelly E. Farnan and Sara M. Metzler of Richards Layton & Finger PA and Dennies Varughese, Adam C. LaRock, Deirdre M. Wells, Daniel S. Block, Jonathan Tuminaro, Christina E. Dashe and Sasha S. Rao of Sterne Kessler Goldstein & Fox PLLC.

Airgas is represented by John C. Phillips Jr. and Megan C. Haney of Phillips McLaughlin & Hall PA.

The case is Mallinckrodt Pharmaceuticals Ireland Ltd. et al. v. Airgas Therapeutics LLC et al., case number 1:22-cv-01648, in the U.S. District Court for the District of Delaware.