Evaluation of Irinotecan and Trifluridine/Tipiracil as Fourth-line Treatments After Third-line Nivolumab for Advanced Gastric Cancer

Background/Aim: Irinotecan and trifluridine/ tipiracil (FTD/TPI) are fourth-line treatment options after third-line nivolumab for advanced gastric cancer (AGC). However, the efficacy and safety of irinotecan and FTD/TPI in the fourth-line setting after third-line nivolumab remains unclear. This study aimed to evaluate the efficacy and safety of irinotecan and FTD/TPI in the fourth-line setting after third -line nivolumab. Patients and Methods: We identified 137 AGC patients treated with nivolumab as third-line treatment in our institute between October 2017 and July 2021. Of these, we recruited 19 AGC patients who initiated irinotecan and 23 AGC patients who initiated FTD/TPI in the fourth-line setting until September 2021. Results: The median overall survival was 5.83 months for irinotecan and 6.31 months for FTD/TPI. Median time-to-treatment failure was 2.07 months for irinotecan and 1.64 months for FTD/TPI. While the frequency of all-grade diarrhea was higher in irinotecan (36% vs. 17%), grade >= 3 neutropenia tended to be higher in FTD/TPI (21% vs. 35%). Conclusion: Irinotecan and FTD/TPI may be clinically useful as fourth-line treatments after nivolumab.