A method for treating small cell lung cancer (SCLC) is provided. In the method a therapeutically effective amount of a compound of Formula I:, wherein R1, R2and R3have the definitions disclosed in the specification, is administered alone or in combination with one or more anticancer agents, or surgery, radiation therapy, chemotherapy, and/or targeted therapy.本發明提供一種治療小細胞肺癌(SCLC)之方法。在該方法中,單獨或與一或多種抗癌劑、或手術、輻射療法、化學療法及/或靶向療法組合投予治療有效量之式I化合物:, 其中R1、R2及R3具有說明書中揭露之定義。