The most frequent grade @ or @ drug-related adverse events were rash or acne ( @ -LSB- @ % -RSB- of @ patients in the afatinib group vs none of @ patients in the methotrexate group ) , diarrhoea ( @ -LSB- @ % -RSB- vs three -LSB- @ % -RSB- ) , stomatitis ( @ -LSB- @ % -RSB- vs @ -LSB- @ % -RSB- ) , fatigue ( @ -LSB- @ % -RSB- vs five -LSB- @ % -RSB- ) , and neutropenia ( @ -LSB- < @ % -RSB- vs @ -LSB- @ % -RSB- ) ; serious adverse events occurred in @ ( @ % ) of afatinib-treated patients and @ ( @ % ) of methotrexate-treated patients .