(A) In vivo effect of Prodrug 8 on D121 Lewis lung carcinoma. Starting on day 5, when the tumors averaged ≈4 mm in diameter, the D121 tumor mice were treated with 3 mg/kg separately on day 5, 8, 11, 14 and 17. 6 mice were used in each group; (p<0.001). (B) Prodrug 8 suppresses spontaneous lung metastasis in D121 mouse models; (p<0.001).