114PEfficacy and safety of the combination of bevacizumab with raltitrexed-based chemotherapy as second-line therapy in patients with metastatic colorectal cancer (mCRC): An interim analysis of a multicenter phase II trial

Abstract Background There are limited treatment options after failure of first-line fluoropyrimidine-based chemotherapy in mCRC. We studied the efficacy and safety of bevacizumab plus raltitrexed-based (Saiweijian®) chemotherapy as second-line therapy in Chinese patients with mCRC. Methods Trial design: Open-label, single-arm, multicenter, phase II trial (NCT03126071).100 patients were required. Enrolled patients were treated with BEV+SALIRI(bevacizumab 7.5mg/kg d1, raltitrexed 3mg/m2 d1, irinotecan 250mg/m2 d1,q3w) or BEV+SALOX(bevacizumab 7.5mg/kg d1,raltitrexed 3mg/m2 d1, oxaliplatin 130mg/m2 d1,q3w)(depending on first-line regimen). Patients treated for 6 cycles with efficacy evaluation SD or above were followed by maintenance therapy(bevacizumab7.5 mg/kg d1, raltitrexed 3 mg/m2 d1,q3w) until disease progression or intolerable toxicity. The primary endpoint was progression-free survival (PFS), and the secondary endpoints were objective response rate (ORR), disease control rate (DCR), overall survival (OS), quality of life (QOL) and safety. Results Between 12/2016 and 5/2019, 63 patients were enrolled. [The median age was 58 years(range:27-74 years), ECOG PS 1 scored 95.2%. ] A total of 376 cycles were completed and 21 patients recieved maintenance therapy. 56 patients were evaluable and ORR was 26.8%, DCR was 78.6%. 52 patients reached the primary endpoint,the median PFS (mPFS) was 5.7 months (95% CI: 1.5-16.7), the median OS (mOS) was not observed. Adverse events (AE) were mostly grade 1/2, and ≧grade 3 treatment-related AEs were mainly neutropenia (7.9%), leukopenia (6.3%), thrombocytopenia (6.3%), alanine aminotransferase increased (4.8%), aspartate aminotransferase increased (6.3%), nausea (3.2%), diarrhea (4.8%) and fatigue (3.2%). Conclusions Our interim results suggest that the combination of bevacizumab with raltitrexed-based chemotherapy could be an efficient and safe second-line treatment option for patients with mCRC. This trial will progress as planned. Legal entity responsible for the study The authors. Funding Has not received any funding. Disclosure All authors have declared no conflicts of interest.