According to a Reuters, Astellas has filed a lawsuit in Delaware Court of Chancery seeking to stop OSI’s directors engaging in any action that will interfere with the offer.
OSI, which shares rights to the blockbuster cancer drug Tarceva with Swiss drugmaker Roche, acknowledged Astellas' offer, describing it as unsolicited and adding that the board “is not interested in undertaking a sale...at that price.”
The New York firm has not yet commented on the US lawsuit.