A phase 1 study tested a therapeutic peptide vaccine targeting the DNAJB1-PRKACA fusion kinase in patients with fibrolamellar hepatocellular carcinoma. Patients received the vaccine in combination with the immunotherapeutics nivolumab and ipilimumab. Treatment was mostly safe and well tolerated. Encouraging preliminary clinical responses were observed in some patients. Translational analysis confirmed the activation of specific immune responses against the target kinase. The study did not provide data on long-term efficacy or overall survival. The results suggest the potential of this combination therapy for further investigation.