Median progression-free survival among patients randomized to chemotherapy was @ weeks ( @ % CI , @-@ @ weeks ; median treatment duration , @ weeks ; interquartile range -LSB- IQR -RSB- , @-@ weeks ) and among those randomized to selumetinib was @ weeks ( @ % CI , @-@ @ weeks ; median treatment duration , @ weeks ; IQR , @-@ @ weeks ) ( hazard ratio , @ ; @ % CI , @-@ @ ; P < @ ) .