Background:

Tipiracil is a thymidine phosphorylase (TPase) inhibitor. thymidine phosphorylase[1]

Tipiracil is an inhibitor of thymidine phosphorylase. Tipiracil increases trifluridine exposure by inhibiting its metabolism by thymidine phosphorylase. The combination of Trifluridine and Tipiracil is a new oral treatment for metastatic colorectal cancer[2]. Tipiracil prevents degradation of FTD through a first-pass effect as a thymidine phosphorylase inhibitor[3].

[1]. Lee SJ, et al. Thymidine phosphorylase influences [(18)F]fluorothymidine uptake in cancer cells and patients with non-small cell lung cancer. Eur J Nucl Med Mol Imaging. 2014 Jul;41(7):1327-35. [2]. Raedler LA. Lonsurf (Trifluridine plus Tipiracil): A New Oral Treatment Approved for Patients with Metastatic Colorectal Cancer. Am Health Drug Benefits. 2016 Mar;9(Spec Feature):97-100. [3]. Tanaka N, et al. Repeated oral dosing of TAS-102 confers high trifluridine incorporation into DNA and sustained antitumor activity in mouse models. Oncol Rep. 2014 Dec;32(6):2319-26.