Mayne Pharma slumps 30% as Cosette threatens to scrap $432 million deal

Mayne Pharma shares plummeted 30% after Cosette Pharmaceuticals threatened to withdraw from its A$672 million ($432.1 million) acquisition of the Australian firm, citing a "material adverse change" based on Mayne's trading performance, a legal case with TherapeuticsMD, and recent FDA discussions, including concerns about promotional claims for Nextstellis; Cosette has initiated a 10-day consultation period, after which it may terminate the deal, though Mayne has rejected the issues raised and remains open to talks.

Analysis

Mayne Pharma (MYX.AX) shares plummeted 30.3%, marking a potential worst trading day since March 2009, after U.S.-based Cosette Pharmaceuticals initiated a review of its A$672 million ($432.1 million) acquisition offer, citing a "material adverse change" (MAC). This review, as per the February agreement, is triggered by significant negative developments impacting Mayne's financial health, business, or outlook. Cosette has specifically pointed to Mayne's recent trading performance, its nine-month earnings update, an ongoing legal case with TherapeuticsMD, and recent communications with the U.S. Food and Drug Administration (FDA), including concerns over promotional claims for its oral contraceptive, Nextstellis. The invocation of the MAC clause has initiated a mandatory 10-business-day consultation period, after which Cosette may terminate the deal if no satisfactory resolution is reached. Mayne Pharma has rejected the issues raised by Cosette but remains open to discussions. The overall negative sentiment score of -0.7, and a specific -0.8 for MYX.AX, reflects significant market concern over the deal's viability and Mayne's underlying business challenges.

Key Decisions for Investors

• Investors should brace for continued high volatility in Mayne Pharma's stock and closely monitor the outcome of the 10-business-day consultation period, as the risk of the A$672 million Cosette acquisition collapsing is substantial.
• Given the multiple negative catalysts cited by Cosette – including trading performance, earnings, legal issues, and FDA scrutiny – a re-evaluation of Mayne Pharma's standalone valuation and downside risk is critical, especially if the deal is terminated.
• Extreme caution is advised for any new or existing positions in MYX.AX, as the failure of the acquisition could trigger further significant share price declines and highlight fundamental weaknesses within Mayne Pharma's operations and regulatory compliance.