Second-Line Fluoropyrimidine-Based Chemotherapy in Advanced Biliary Tract Cancer: A Meta-Analysis Based on Individual Patient-Level Data of Randomized Trials.

Purpose: While fluoropyrimidine-based chemotherapy regimens are recommended second-line treatment for patients with advanced biliary tract cancer (BTC), there have been no studies comparing different regimens head-to-head.

Materials and methods: We performed individual patient-level meta-analysis based on data from the intention-to-treat population of the phase 2b NIFTY trial (liposomal irinotecan [nal-IRI] plus fluorouracil and leucovorin [5-FU/LV] vs. 5-FU/LV; NCT03542508) and the phase 2 FIReFOX trial (modified oxaliplatin plus 5-FU/LV [mFOLFOX] vs. modified irinotecan plus 5-FU/LV [mFOLFIRI]; NCT03464968). Pairwise log-rank tests and multivariable analysis using Cox proportional hazards modeling with shared frailty to account for the trial's effect were used to compare overall survival (OS) between regimens.

Results: A total of 277 patients were included. The nal-IRI plus 5-FU/LV group (n=88) showed significantly better OS compared to the mFOLFOX group (n=49, pairwise log-rank, p=0.02), and mFOLFIRI group (n=50, p =0.03). Multivariable analysis showed consistent trends in OS with adjusted hazard ratios of 1.39 (mFOLFOX vs nal-IRI plus 5-FU/LV, 95% CI 0.93-2.07, p=0.11) and 1.36 (mFOLFIRI vs nal-IRI plus 5-FU/LV, 95% CI 0.92-2.03, p=0.13), respectively. Compared to the 5-FU/LV group, the mFOLFOX group and the mFOLFIRI group did not show differences in terms of OS (pairwise log-rank p=0.83 and p=0.58, respectively). The nal-IRI plus 5-FU/LV group experienced more frequent diarrhea, while the mFOLFOX group experienced peripheral neuropathy.

Conclusion: Nal-IRI plus 5-FU/LV showed favorable survival outcomes compared to mFOLFOX, mFOLFIRI, or 5-FU/LV. The safety profiles of these regimens should be considered along with efficacy.