raltitrexed + S-1

Raltitrexed + S-1 is a combination chemotherapy regimen used primarily as a third-line or later treatment for refractory metastatic colorectal cancer (mCRC). Raltitrexed is a thymidylate synthase (TS) inhibitor, while S-1 is an oral fluoropyrimidine derivative that contains tegafur (a prodrug of 5-fluorouracil), gimeracil (a dihydropyrimidine dehydrogenase [DPD] inhibitor), and oteracil potassium. The rationale for this combination lies in overcoming resistance to 5-fluorouracil by inhibiting both TS and DPD, two key enzymes involved in the metabolism of fluoropyrimidines. Clinical studies have shown that this combination demonstrates moderate efficacy and manageable safety as salvage therapy in patients with mCRC who have failed standard treatments such as 5-FU, oxaliplatin, and irinotecan[1][2][4].

Other names

raltitrexed and S-1RS regimen