Purpose: After 10 years of clinical practice and research studies, there are still no validated prognostic or predictive factors of response to sorafenib for hepatocellular carcinoma (HCC). On the basis of the results of our two retrospective studies, we designed the multicenter INNOVATE study with the aim to validate the role of nitric oxide synthase 3 (NOS3) and ANGPT2 polymorphisms in patients with HCC treated with sorafenib [NCT02786342]. Patients and Methods: This prospective multicenter study was conducted at 10 centers in Italy. All eligible patients received a continuous oral treatment with 400 mg of sorafenib twice daily. Genotyping analysis was performed for NOS3 (rs2070744) and ANGPT2 SNPs (rs55633437). The primary outcome was progression-free survival (PFS), whereas secondary outcomes included overall survival (OS) and disease-control rate. Results: A total of 165 patients were enrolled between March 2016 and June 2018. NOS3 rs2070744 CC/CT genotypes were significantly associated with a higher median PFS (5.9 months vs. 2.4 months; HR ¼ 0.43; P ¼ 0.0007) and OS (15.7 months vs. 8.6 months; HR ¼ 0.38; P < 0.0001) compared with TT genotype. There was no statistically significant association between ANGPT2 rs55633437 TT/GT genotypes and PFS (2.4 months vs. 5.7 months; HR ¼ 1.93; P ¼ 0.0833) and OS (15.1 months vs. 13.0 months; HR ¼ 2.68; P ¼ 0.55) when compared with the other genotype. Following adjustment for clinical covariates, multivariate analysis confirmed NOS3 as an independent prognostic factor for PFS (HR ¼ 0.50; P ¼ 0.0128) and OS (HR ¼ 0.29; P ¼ 0.0041). Conclusions: The INNOVATE study met the primary endpoint, confirming that patients with advanced HCC with NOS3 rs2070744 CC/CT genotypes had a better prognosis with respect to TT genotype patients. © 2020 American Association for Cancer Research.