BRIDGEWATER, N.J.--(BUSINESS WIRE)--Enzon Pharmaceuticals, Inc. (Nasdaq: ENZN) today commenced its previously announced “Modified Dutch Auction” tender offer for up to $133,333,000 principal amount of its 4% Convertible Senior Notes due 2013 . The terms and conditions are set forth in the offer to purchase and related letter of transmittal, each dated December 8, 2008.