Treatments (tx) after progression to first-line FOLFOXIRI plus bevacizumab (bev) in metastatic colorectal cancer (mCRC) patients (pts): A pooled analysis of TRIBE and MOMA studies by GONO group.

Abstract

3542 Background: FOLFOXIRI plus bev is regarded by international guidelines as a valuable option in the first-line tx of mCRC pts. One of the major concerns for the adoption of this regimen is the potential limitation of subsequent therapeutic options. The aim of the present analysis was to focus on treatments received after progression in TRIBE (NCT00719797) and MOMA (NCTNCT02271464) studies. Methods: We collected data of tx received after progression and their outcome in terms of 2ndPFS (time from 2nd line tx start to disease progression or death) and OS II (time from 2nd line tx start to death). For pts in which the same drugs used in first-line were totally or partially reintroduced, the chemotherapy-free interval (CFI, time from the last administration of irinotecan or oxaliplatin during first-line to disease progression) was calculated. Results: Out of 482 pts treated with upfront FOLFOXIRI plus bev, 429 progressed. 303 (70.6%) pts received a 2nd line tx: 93 FOLFOXIRI +/- bev (Group A), 119 FOLFOX/XELOX or FOLFIRI +/- bev (Group B) and 91 other tx (Group C), including an anti-EGFR moAb in 60 cases. No difference was observed among the three groups in terms of 2ndPFS (median 2nd PFS Group A: 5.6 vs Group B: 4.4 vs Group C: 3.9 mos; p = 0.60) or OS II (median OS II Group A: 14.9 vs Group B: 13.8 vs Group C: 11.7 mos; p = 0.49). In the subgroup of pts with a CFI < 6 mos, Group A (n = 52) reported longer 2ndPFS compared to both Group B (n = 58) (median 2ndPFS 5.3 vs 3.0 mos; HR: 0.61,95%CI 0.41-0.89; p = 0.009) and Group C (n = 58) (5.3 vs 3.2 mos; HR: 0.71, 95%CI 0.48-1.05; p = 0.07). Consistent results were achieved in OS II (Group A vs Group B; median OS 13.6 vs 10.8 mos; HR: 0.65, 95%CI 0.42-1.00; p = 0.053; Group A vs Group C 13.6 vs 8.9 mos; HR: 0.60, 95%CI 0.39-0.93; p = 0.002). In the subgroup of pts with a CFI ≥ 6 mos, no significant difference was shown between Group A (n = 41) and Group B (n = 61) or C (n = 33). Conclusions: Tx after progression to first-line FOLFOXIRI plus bev are feasible and show expected efficacy results. The reintroduction of the triplet plus bev seems more effective than doublets plus bev or other tx when a more aggressive disease biology is suggested (CFI < 6 mos).