BOSTON: Reigning champions Robert Kiprono Cheruiyot of Kenya and Teyba Erkesso of Ethiopia will try to defend their Boston Marathon titles next April, race organizers announced Thursday. The 115th Boston Marathon, to be staged April 18, will see Cheruiyot try to challenge his course record of 2 hrs 5mins 52secs. Erkesso took the women's crown last year in 2:26:11. Kenya's Geoffrey Mutai, last year's Rotterdam Marathon runner-up, will lead a pack of top challengers from around the world.