Mallinckrodt plc, an American-Irish pharmaceutical company, and Endo Inc, a Pennsylvania-based pharmaceutical company, announced on Friday that they have completed their merger to create a global, scaled, diversified therapeutics company.

The parties claim that the combined company is well-positioned to continue growing its brands portfolio across a wide range of therapeutic areas of significant unmet need, including endocrinology, gastroenterology, hepatology, neonatal respiratory critical care, nephrology, neurology, pulmonology, ophthalmology, orthopaedics, rheumatology, and urology.

In addition, the generics and sterile injectables business features a broad product portfolio, a controlled substances franchise, commercial and manufacturing infrastructure in the US and internationally, extensive supply chain capabilities, and expertise in complex, highly regulated products. This business operates under the Par Health name and is intended to be spun off as an independent company with a target date of the fourth quarter of 2025, subject to approval by Mallinckrodt's board of directors and other conditions.

The combined company is expected to generate at least USD150m of annual pre-tax run-rate operating synergies by Year 3, and approximately USD75m of pre-tax run rate synergies in the first 12 months post-merger, driven by business function integration and R&D savings from economies of scale, among other areas.

Following the spin-off of Par Health, the branded therapeutics company is expected to be listed on the New York Stock Exchange (NYSE), subject to approval of Mallinckrodt's board of directors.

Under the terms of the deal, which was announced in March 2025, Endo shareholders received a total of USD100m in cash and own 49.9% of Mallinckrodt on a pro forma basis. Mallinckrodt's pre-transaction shareholders own 50.1% of Mallinckrodt. The aggregate cash amount to Endo shareholders was increased from USD80m to USD100m to compensate for a reduction in the exchange ratio that was triggered to ensure that Mallinckrodt's pre-transaction shareholders own 50.1% of Mallinckrodt post-closing. On a per share basis, Endo shareholders are entitled to receive approximately USD1.31 in cash and 0.2575 of Mallinckrodt shares. Endo shares have ceased trading on the OTCQX.

In addition, a subsidiary of Mallinckrodt that will operate the generics and sterile injectables business incurred a USD1.35bn secured credit facility, consisting of a USD150m revolving credit facility and a USD1.2bn term loan credit facility. Proceeds from the facility were used to pay off Mallinckrodt's senior secured term loans and redeem Mallinckrodt's senior secured notes concurrently with the completion of the business combination. The remaining proceeds were or will be used to finance the transaction and transaction costs or for general corporate purposes. Endo's debt remains outstanding.