AbstractBackgroundPatients with advanced hepatocellular carcinoma (HCC) and poor liver function lack effective systemic therapies. Low‐energy electromagnetic fields (EMFs) can influence cell biological processes via non‐thermal effects and may represent a new treatment option.MethodsThis single‐site feasibility trial enrolled patients with advanced HCC, Child‐Pugh A and B, Eastern Cooperative Oncology Group 0–2. Patients underwent 90‐min amplitude‐modulated EMF exposure procedures every 2–4 weeks, using the AutEMdev (Autem Therapeutics). Patients could also receive standard care. The primary endpoints were safety and the identification of hemodynamic variability patterns. Exploratory endpoints included health‐related quality of life (HRQoL), overall survival (OS). and objective response rate (ORR) using RECIST v1.1.ResultsSixty‐six patients with advanced HCC received 539 AutEMdev procedures (median follow‐up, 30 months). No serious adverse events occurred during procedures. Self‐limiting grade 1 somnolence occurred in 78.7% of patients. Hemodynamic variability during EMF exposure was associated with specific amplitude‐modulation frequencies. HRQoL was maintained or improved among patients remaining on treatment. Median OS was 11.3 months (95% confidence interval [CI]: 6.0, 16.6) overall (16.0 months [95% CI: 4.4, 27.6] and 12.0 months [6.4, 17.6] for combination therapy and monotherapy, respectively). ORR was 24.3% (32% and 17% for combination therapy and monotherapy, respectively).ConclusionAutEMdev EMF exposure has an excellent safety profile in patients with advanced HCC. Hemodynamic alterations at personalized frequencies may represent a surrogate of anti‐tumor efficacy. NCT01686412.