SO-16 FIRE-4 (AIO-KRK-0114): Randomized study for a switch maintenance concept with 5-FU plus bevacizumab after induction treatment with FOLFIRI plus cetuximab versus continued treatment with FOLFIRI plus cetuximab – secondary endpoint

FIRE-4 (AIO KRK-0114) is performed in RAS-wild-type (wt) mCRC patients. This randomized study tests the efficacy of early switch maintenance during 1st-line therapy (part 1) and re-challenge with cetuximab 2) later-line treatment. In part 1, all patients received first-line induction treatment FOLFIRI plus (FOLFIRI/Cet). arm A, were to continue FOLFIRI/Cet until progression or intolerable toxicity. B, for 8-12 cycles, after which 5-FU/FA bevacizumab (5-FU/Bev) was applied. The first randomization evaluates question if an from may prolong PFS. this randomized, controlled, open-label phase-III study, (irinotecan 5-FU/FA) every two weeks at standard dosing schedule. continued 2 De- re-escalation allowed according local care. 8 cycles (in case tumor response) 12 stable disease) followed by (5mg/kg) disease Overall survival second evaluated as a primary endpoint. Here, we report PFS secondary endpoint study. Other endpoints included ORR, OS, safety, tolerability. present analysis investigates impact sidedness on results. From August 2015 January 2021, 672 656 assigned 120 German 10 Austrian centers (327 A 329 B). overall population demonstrated comparable outcome data both arms. Among 643 evaluable sidedness, 84% (n=539) presented left-sided tumors 16% (n=104) right-sided tumors. left sided results obtained arms (A vs B) regard ORR (78.8% 78.0%), (11.5 months 11.6 months), OS (33.2 35.6 months). tumors, (arms generally less favorable. numerically superior application (56.8% 42.2%, P=0.27). However, appeared be more favorable (B) (5.5 7.4 months, P=0.38) (12.5 21.2 confirms RAS wild-type mCRC. induced 5-FU bevacizumab. While differences did not reach level statistical significance, are favor switch-maintenance arm.