TAS-102 is a combination of two active ingredients: trifluridine (TFT), a nucleoside analog, and tipiracil (TPI), a thymidine phosphorylase inhibitor in a 1.0:0.5 molar ratio (TFT:TPI).1 TFT is the active antitumor component of TAS-102, its monophosphate form inhibits thymidylate synthase, an enzyme...