A second generation ATP-competitive anthrapyrazolone c-Jun N terminal kinase (JNK) inhibitor with potential antineoplastic activity. Based on the chemistry of SP600125, another anthrapyrazolone inhibitor of JNK, CC-401 competitively binds the ATP binding site of JNK, resulting in inhibition of the phosphorylation of the N-terminal activation domain of transcription factor c-Jun; decreased transcription activity of c-Jun; and a variety of cellular effects including decreased cellular proliferation.