612PSPICE, a phase I study of enadenotucirev in combination with nivolumab in tumours of epithelial origin: Analysis of the metastatic colorectal cancer patients in the dose escalation phase

>0.49 in males (HR 2.87, p 0.001), KRAS mutation (HR 1.37 p ¼ 0.008), BRAF mutation (HR 1.69 p ¼ 0.009), sidedness (right vs left HR 1.59, p 0.001) and peritoneal metastases (HR 2.32, p 0.001) were associated with shorter OS.Instead, primary tumor resection (HR 0.37 p 0.001) was associated with prolonged OS.At multivariate analysis, MLR >0.27 in females (HR 2.77, p ¼ 0.002), MLR >0.49 in males (HR 5.39, p 0.001), BRAF mutation (HR 3.38, p 0.001) and peritoneal metastases (HR 2.50, p ¼ 0.003) were still independently associated with worse OS.Noteworthy, high MLR was more frequently found in females than in males (41% vs 9%).Conclusions: Males and females have a different immune response.Our study showed that high MLR, both in males and females, is an unfavorable independent prognostic factor.Further prospective studies are needed to confirm these data.