On 15 October 2025, the NSW Supreme Court handed down a ground-breaking decision reaffirming the high threshold for establishing a material adverse change (MAC) in M&A transactions.
Gilbert + Tobin acted for Mayne Pharma in this landmark case, which has already generated significant market interest and numerous client queries given its implications for deal certainty and contractual risk allocation in Australian M&A transactions.
In the matter of Mayne Pharma Group Limited [2025] NSWSC 1204, the Court rejected Cosette’s termination notices and held that the scheme implementation deed remains on foot. The Court also examined whether, through certain conduct prior to and at the First Court Hearing, Cosette had elected to affirm the deed and waived its rights to terminate.
The G+T team was led by partners Adam Laura, Alexandra Whitby, Colleen Platford and Nirangjan Nagarajah.
In NSW Supreme Court reaffirms high threshold for material adverse change in M&A, we unpack the decision and its immediate impact.
