After a median follow-up of 72 months ( IQR 50-101 months ) in the trastuzumab emtansine group and 65 months ( IQR 41-97 ) in the physician 's choice group , 219 ( 54 % ) patients in the trastuzumab emtansine group and 129 ( 65 % ) of patients in the physician 's choice group had PFS events .