Methods of inhibiting the replication of influenza viruses in a biological sample or patient, of reducing the amount of influenza viruses in a biological sample or patient, and of treating influenza in a patient, comprises administering to said biological sample or patient an effective amount of a compound represented by Structural Formula ( I ): or a pharmaceutically acceptable salt thereof, wherein the values of Structural Formula ( IA ) are as described herein. A compound is represented by Structural Formula ( IA ) or a pharmaceutically acceptable salt thereof, wherein the values of Structural Formula ( IA ) are as described herein. A pharmaceutical composition comprises an effective amount of such a compound or pharmaceutically acceptable salt thereof, and a pharmaceutically acceptable carrier, adjuvant or vehicle.