Tipiracil

Description

Tipiracil (TPI) is a potent and competitive inhibitor of thymidine phosphorylase (TPase) with an IC₅₀ value of 35 nM for human placental TPase. It is selective for TPase over other pyrimidine-metabolizing enzymes (IC₅₀s = >1 mM for UPase, OPRTase, TK, and DPDase). TPI inhibits the phosphorolysis and degradation of trifluorothymidine , a cytotoxic nucleoside, in human breast and colon carcinoma tumor samples. Oral administration of TPI (12.5-50 mg/kg) enhances the anti-tumor activity of trifluorothymidine in a mouse AZ-521 stomach cancer xenograft model. Formulations containing TPI have been used for the treatment of metastatic colorectal cancer.

The Uses of Tipiracil

Tipiracil Hydrochloride serves as a treatment for metastatic colorectal cancer (mCRC). A thymidine phosphorylase inhibitor.

Definition

ChEBI: A hydrochloride obtained by combining tipiracil with one equivalent of hydrochloric acid. Used in combination with trifluridine, a nucleoside metabolic inhibitor, for treatment of advanced/relapsed unresectable colorectal cancer.

Biochem/physiol Actions

Tipiracil is an inhibitor of thymidine phosphorylase. Tipiracil is used in combination with trifluridine as TAS-102 for the treatment of refractory metastatic colorectal cancer. Tipiracil increases the bioavailability of trifluridine by blocking the enzyme that would otherwise protect the tumors by metabolizing trifluridine.

References

1. tsukihara h1, nakagawa f2, sakamoto k et al. efficacy of combination chemotherapy using a novel oral chemotherapeutic agent, tas-102, together with bevacizumab, cetuximab, or panitumumab on human colorectal cancer xenografts. oncol rep. 2015 may;33(5):2135-42. 2. dexter dl, wolberg wh, ansfield fj, helson l and heidelberger c: the clinical pharmacology of 5-trifluoro-methyl-2'-deoxyuridine. cancer res 32: 247-253, 1972.3. fukushima m, suzuki n, emura t et al. structure and activity of specific inhibitors of thymidine phosphorylase to potentiate the function of antitumor 2'-deoxyribonucleosides. biochem pharmacol 59: 1227-1236, 2000.