These patients were randomly assigned in a @:@ ratio to receive afatinib or chemotherapy ( pemetrexed-cisplatin -LSB- LUX-Lung @ -RSB- or gemcitabine-cisplatin -LSB- LUX-Lung @ -RSB- ) , stratified by EGFR mutation ( exon @ deletion -LSB- del@ -RSB- , Leu@Arg , or other ) and ethnic origin ( LUX-Lung @ only ) .