Raltitrexed Chemotherapy Regimen Plus Bevacizumab as Second-Line Treatment for Metastatic Colorectal Cancer: A...

Clinical studies have shown that bevacizumab plus chemotherapy significantly improves efficacy in metastatic colorectal cancer (mCRC). This prospective study aims to investigate the efficacy and safety of changing second-line treatment to raltitrexed-based chemotherapy regimens plus bevacizumab in mCRC patients who have failed the first-line fluorouracil-based chemotherapy regimen with or without bevacizumab/cetuximab.

This is a prospective, open-label, multicenter, phase II clinical study. A total of 100 patients with mCRC after failure of the first-line fluorouracil-based chemotherapy regimen with or without bevacizumab/cetuximab were enrolled from November 2016 to October 2021, and received second-line raltitrexed-based chemotherapy regimen plus bevacizumab. Patients were treated for 6 cycles, and efficacy evaluation over stable disease were followed by maintenance treatment of bevacizumab and raltitrexed until disease progression or intolerable toxicity. The primary endpoint was progression-free survival (PFS). Secondary endpoints included overall survival (OS), objective response rate (ORR), disease control rate (DCR), safety, and toxicity.

Ninety-four patients were treated with SALIRI (raltitrexed + irinotecan) plus bevacizumab, and six patients with SALOX (raltitrexed + oxaliplatin) plus bevacizumab. Median PFS was 8.4 (95% CI: 6.2-11.0) months, including 8.2 (95% CI 6.2, 11.0) months in the SALIRI group and 11.6 (95% CI 3.1, NA) months in the SALOX group. Median OS was 17.6 (95% CI 15.2, 22.0) months in the SALIRI group and 17.1 (95% CI 4.1, NA) months in the SALOX group. ORR and DCR were 25.5% and 87.2% in the SALIRI group, and 33.3% and 83.3% in the SALOX group, respectively. A low incidence of grade 3-4 adverse events was observed.

Raltitrexed-based chemotherapy regimens plus bevacizumab improved survival duration in mCRC patients with failed first-line therapy. Therefore, treatment with raltitrexed-based chemotherapy regimens plus bevacizumab could be a superior therapeutic option for second-line chemotherapy in mCRC (ClinicalTrials.gov registration number: NCT03126071).