This invention pertains to a method for the treatment of non-small cell lung cancer in a subject who is a smoker, comprising administering to the subject an effective amount of 2-[(2R)-2-methylpyrrolidin-2-yl]-1H-benzimidazole-4-carboxamide (veliparib or ABT-888), or a pharmaceutically acceptable salt thereof, in combination with carboplatin and paclitaxel.