Mallinckrodt

Mallinckrodt plc (now Keenova Therapeutics plc) — Founded in 1867 and historically headquartered in Dublin, Ireland, with U.S. operations centered in Hazelwood, Missouri (and a former executive office in Staines-upon-Thames, UK). It is a specialty pharmaceutical manufacturer. Ownership is unusual: the company filed Chapter 11 twice (2020 and August 2023), and when it emerged on November 14, 2023, all pre-existing ordinary shares were extinguished and ownership transferred to its creditors — first- and second-lien lenders including funds managed by Bracebridge Capital and Silver Point. It has not been NYSE-listed since the 2023 delisting. Per company filings, Mallinckrodt had about 2,700 employees and FY2024 net sales of roughly $2.0 billion.

Products / operations. Branded specialty pharmaceuticals: Acthar Gel (repository corticotropin injection) including the SelfJect injector, INOmax (inhaled nitric oxide) and the INOmax Evolve DS delivery system, and Terlivaz (terlipressin). It also ran the Therakos photopheresis business until selling it to CVC Capital Partners for $925 million (closed November 2024), and a Specialty Generics segment spanning controlled-substance active pharmaceutical ingredients (hydrocodone, oxycodone, acetaminophen/APAP) and finished-dosage generics, including generic ADHD products.

Corporate changes. On July 31, 2025 Mallinckrodt merged with Endo, Inc., and on November 10, 2025 spun off its generics and sterile-injectables businesses as Par Health, rebranding the remaining branded company Keenova Therapeutics plc (adding XIAFLEX to the portfolio). Keenova has stated an intent to pursue an NYSE listing in 2026; whether that has occurred as of today is unverified. As Keenova it guided to 2026 net sales of $1.94–2.00 billion and reports more than 1,600 employees post-spinoff.

Litigation posture. An operating company, not an NPE: zero plaintiff-side appearances and one defendant-side appearance in the tracked data. That single case is In re Xyrem (Sodium Oxybate) Antitrust Litigation (MDL No. 2966, N.D. Cal., Judge Seeborg), where Mallinckrodt LLC is named among generic manufacturers alleged to have entered unlawful market-allocation/pay-for-delay agreements with Jazz Pharmaceuticals over generic sodium oxybate. The matter is antitrust, not patent infringement, and the venue is an MDL consolidation in the Northern District of California rather than a plaintiff-friendly patent venue. Beyond this tracked case, Mallinckrodt has historically faced extensive opioid- and Acthar-related litigation, including settlements addressed in its bankruptcies.