Efficacy and safety of ramucirumab plus modified FOLFIRI for metastatic colorectal cancer

Dose modification of chemotherapy for metastatic colorectal cancer (MCRC) is often needed, especially in second-line and later-line treatments due to adverse events of previous treatment and poor patient condition. No study has focused on ramucirumab plus modified dose of FOLFIRI for MCRC, and whether low relative dose intensity (RDI) affects treatment efficacy has not been clarified. MCRC patients who received ramucirumab plus FOLFIRI, which consisted of 150 mg/m2 of irinotecan, at six institutions were retrospectively analyzed. A total of 43 patients were assessed. Median age was 63 years, and 22 patients (51%) were women. Twenty-six patients (60%) were given ramucirumab plus FOLFIRI as second-line therapy, and 17 (40%) as third or later-line. The median relative dose intensity (RDI) of irinotecan was 60.6%, which is lower than that in the pivotal phase 3 study (RAISE), and other agents showed the same trend. Median progression-free survival was 4.8 [95% confidence interval (CI) 3.2–5.7] months for all patients, 5.4 (95% CI 3.5–7.2) months for second-line patients, and 2.8 (95% CI 1.6–5.8) months for third or later-line patients. Median overall survival was 17.3 (95% CI 11.5–22.4) months for all patients. Patients with irinotecan RDI less than 60% showed similar treatment efficacy. Hematological toxicities of grade 3 or worse were observed in 21 patients, but all were manageable. Low RDI did not compromise the treatment efficacy of ramucirumab plus modified FOLFIRI for MCRC patients.