definiens: means any of the following events : ( a ) any Third Party becomes the beneficialowner, directly or indirectly, of more than fifty percent ( 50 % ) of the Total Voting Power of all Voting Securities ofImmunoGen then outstanding, as a result of a single transaction or a series of related transactions ; ( b ) ImmunoGenconsolidates with or merges into a Third Party, or any such Third Party consolidates with or merges into [COMPANY], in either event pursuant to a transaction in which more than fifty percent ( 50 % ) of the Total Voting Power of all VotingSecurities of the surviving entity then outstanding is not held by the parties holding at least fifty percent ( 50 % ) of theTotal Voting Power of all Voting Securities of [COMPANY] outstanding immediately prior to such consolidation ormerger ; or ( c ) [COMPANY] conveys, transfers or leases all or substantially all of its assets to a Third Party