[Problem] Provided is a pharmaceutical composition for treating lung cancer involving mitochondrial Complex I, particularly non-small cell lung cancer. [Solution] After investigating compounds having a mitochondrial Complex I inhibitory effect, the present inventor completed the present invention by confirming that the bicyclic nitrogen-containing aromatic heterocyclic amide compounds of the present invention have a mitochondrial Complex I inhibitory effect, and that these compounds have an antitumor effect on mice carrying cancer derived from non-small cell lung cancer.
