Growth Inhibition of Mouse Skin Tumor by Serine Protease Inhibitor ONO-3403

The study investigated the effects of the serine protease inhibitor ONO-3403 on mouse skin tumors induced by 3-methylcholanthrene. ONO-3403, an analog of FOY-305, demonstrated significantly lower IC50 values against serine proteases compared to FOY-305. In the experiment, seven mice were administered ONO-3403 intraperitoneally at a dose of 4 mg/kg twice daily for 5 weeks. The treatment resulted in potent tumor growth suppression (p<0.001) without causing side effects such as hair loss or body weight loss. These findings suggested that ONO-3403 could be a potential treatment for squamous cell carcinoma.