BRIDGEWATER, N.J. — Cosette Pharmaceuticals, Inc., a U.S.-based fully integrated pharmaceutical company, said it has terminated its agreement to acquire Australia-based Mayne Pharma Group Limited following regulatory intervention and the expiration of the deal’s end date.
Cosette said it served a notice of termination on Mayne Pharma on December 9, 2025, ending the Scheme Implementation Deed under which Cosette was to acquire all outstanding shares of Mayne Pharma. The company also acknowledged disclosures made by Mayne Pharma on December 10 and December 11, and confirmed that Mayne Pharma issued its own notice of termination on December 11.
The termination follows a ruling by the Treasurer of Australia blocking the proposed transaction, as well as the expiration of the Scheme Implementation Deed’s end date in November.
Cosette said it strongly rejects Mayne Pharma’s claims that Cosette breached the agreement and stated that Mayne Pharma’s December 10 and December 11 announcements to the Australian Securities Exchange contain material inaccuracies. According to Cosette, it has been fully transparent in its engagement with Australian regulators and has complied with all legal obligations, including those under the Scheme Implementation Deed.
The company said it will vigorously defend itself against Mayne Pharma’s allegations if required. Cosette also said it intends to pursue an appeal of the adverse judgment of the Supreme Court of New South Wales and, if necessary, pursue claims against Mayne Pharma for harm it says resulted from Mayne Pharma’s conduct.
Despite the termination of the proposed acquisition, Cosette said it remains well positioned to continue the transformation of its business achieved over the past five years, driven by strategic business development, operational execution, and a robust research and development and business development pipeline.
Cosette said it maintains a diversified product portfolio that includes branded products such as CLOMID, VYLEESI and INTRAROSA. Its higher-growth portfolio is supported by an established products business that generates strong cash flow, including brands such as AMBIEN, AMBIEN CR, WELCHOL and BENICAR. The company also markets more than 100 generic products and operates a manufacturing facility in Lincolnton, North Carolina.
