Final results of study 20050181: A randomized phase III study of FOLFIRI with our without panitumumab (pmab) for the second‑line treatment (tx) of metastatic colorectal cancer (mCRC).

3535 Background: The primary analysis of study 20050181 showed that in patients (pts) with wild-type (WT) KRAS mCRC, pmab plus FOLFIRI given as second-line therapy significantly improved progression-free survival (PFS) vs FOLFIRI alone. Here, we report on a prespecified descriptive analysis planned for 30 months (mos) after the last pt was enrolled. Methods: Pts with mCRC, ECOG 0-2, who had one prior fluoropyrimidine-based chemotherapy regimen were randomized 1:1 to pmab 6.0 mg/kg Q2W+FOLFIRI (Arm 1) vs FOLFIRI (Arm 2). Co-primary endpoints were OS and PFS (central assessment). Secondary endpoints included objective response rate (ORR) and safety. Tumor KRAS status was determined by a blinded central lab. Results: 1186 pts were randomised and received tx: 591 in Arm 1, 595 In Arm 2. 1083 pts (91%) had KRAS results. Adverse event rates were consistent with the primary analysis. Results are shown below. Conclusions: In pts with WT KRAS mCRC receiving pmab+FOLFIRI vs FOLFIRI, PFS and ORR were significantly i...