Fluorouracil and bevacizumab plus anakinra for patients with metastatic colorectal cancer refractory to standard therapies (IRAFU): a single-arm phase 2 study

Abstract

ABSTRACTIn preclinical models, IL-1β inhibition could enhance the efficacy of fluorouracil (5-FU). In this phase 2 study, we assessed the activity and safety of 5-FU plus bevacizumab and anakinra (an IL-1β and α inhibitor) in patients with metastatic colorectal (mCRC) refractory to chemotherapy and anti-angiogenic therapy.Eligible patients had unresectable mCRC; were refractory or intolerant to fluoropyrimidine, irinotecan, oxaliplatin, anti-VEGF therapy, and anti-EGFR therapy (for tumors with wild-type KRAS). Patients were treated with a simplified acid folinic plus 5-FU regimen and bevacizumab (5 mg/kg) both administered by intravenous infusion for 30 min every 2 weeks. Anakinra (100 mg) was injected subcutaneously once daily. The primary endpoint was the 2-month response rate determined upon CHOI criteria.Thirty two patients with metastatic colorectal cancer were enrolled. Five patients demonstrated response (Choi criteria) and 22 patients had stable disease as the best 2-month overall response. Median progression-free and overall survival were 5.4 (95% CI, 3.6–6.6) and 14.5 months (95% CI, 9–20.6) respectively. Twenty patients experienced grade 3 toxicity. No grade 4 or 5 toxicity related to therapy occurred. The most common grade 3 adverse events were neutropenia in 8 (25%) patients, digestive side effects in 7 (21.9%) patients and hypertension in 6 (18.75%) patients. No treatment-related deaths or serious adverse events were reported.5-FU plus bevacizumab and anakinra has promising activity and a manageable safety profile, suggesting that this combination might become a potential treatment option for patients with refractory mCRC.