Shares of Mayne Pharma plunged 30% on Wednesday after U.S.-based Cosette Pharmaceuticals initiated a review of its A$672 million ($432.1 million) acquisition, citing a "material adverse change" in the Australian firm's business and finances.
Mayne Pharma has filed a patent infringement lawsuit against Indian drugmaker Sun Pharma in a U.S. court, the Australian drugmaker said on Thursday.