Trifluridine/tipiracil (Lonsurf(®)) is a novel, orally active, antimetabolite 
agent comprised of trifluridine, a thymidine-based nucleoside analogue, and 
tipiracil, a potent thymidine phosphorylase inhibitor. Trifluridine is 
incorporated into DNA via phosphorylation, ultimately inhibiting cell 
proliferation. Tipiracil increases systemic exposure of trifluridine when 
coadministered. Trifluridine/tipiracil has recently been approved for the 
treatment of adult patients with metastatic colorectal cancer (mCRC) who are 
refractory to or are not considered candidates for, current standard 
chemotherapy and biological therapy in the EU and USA and in unresectable 
advanced or recurrent CRC in Japan. The approved regimen of oral twice-daily 
trifluridine/tipiracil (35 mg/m(2) twice daily on days 1-5 and 8-12 of each 
28-day cycle) significantly improved overall survival and progression-free 
survival and was associated with a significantly higher disease control rate 
than placebo when added to best supportive care in the multinational, pivotal 
phase III trial (RECOURSE) and a phase II Japanese trial. Trifluridine/tipiracil 
was associated with an acceptable tolerability profile, with adverse events 
generally being managed with dose reductions, temporary interruptions in 
treatment or administration of granulocyte-colony stimulating factor. The most 
common grade 3-4 adverse events (≥10 %) were anaemia, neutropenia, 
thrombocytopenia and leukopenia. In conclusion, trifluridine/tipiracil is a 
useful additional treatment option for the management of mCRC in patients who 
are refractory to, or are not considered candidates for, currently available 
therapies.