In patients who received at least one dose of study drug , the most frequent grade @-@ adverse events were diarrhoea ( @ -LSB- @ % -RSB- patients in the dacomitinib group vs ten -LSB- @ % -RSB- patients in the erlotinib group ) , rash ( @ -LSB- @ % -RSB- vs @ -LSB- @ % -RSB- ) , and stomatitis ( @ -LSB- @ % -RSB- vs two -LSB- < @ % -RSB- ) .