Impact of first-line bevacizumab (BV) on the clinical outcomes of patients with metastatic colorectal cancer (mCRC) treated with second-line FOLFIRI plus BV.

e14565 Background: In a phase II study (CR0802; UMIN000001817) of second-line FOLFIRI plus BV for mCRC, quarter of the enrolled patients did not receive BV in their first-line treatment. We analyzed the impact of prior BV use on the outcomes of FOLFIRI plus BV. Methods: Patients with FOLFOX-pretreated mCRC received up to 24 cycles of FOLFIRI plus BV. The efficacy of the treatment was compared between patients who had previously received BV (i.e., FOLFOX plus BV) and those who had not. Results: Patient characteristics were well-balanced between patients with (N =69) and without (N =20) prior BV use in the first-line treatment. Progression-free survival (PFS) and overall survival (OS) from the start of second-line treatment significantly differed between the two groups in favor of those without prior BV use (Table). Response rate (RR) for patients without prior BV use was higher than that for those with prior BV use. There was no substantial difference in median relative dose intensity of FOLFIRI plus BV as...