The effectivity of targeted therapy and immunotherapy in patients with advanced metastatic and non-metastatic cancer of the esophagus and esophago-gastric junction

Therapies that target specific tumor drivers or immune checkpoints are increasingly explored for esophageal cancer patients. This review addresses developments in therapies with targeted anti-human epidermal growth factor receptor 2 (HER2) agents and immune checkpoint inhibitors in patients with stage IV esophageal cancer. First-line palliative treatment with the anti-HER2 agent trastuzumab in combination with chemotherapy has been approved for use in patients with HER2 positive gastro-esophageal adenocarcinoma. Neoadjuvant chemoradiotherapy plus perioperative trastuzumab however has not demonstrated a survival benefit in advanced esophageal cancer patients eligible for surgery. Potentially better responses are expected with dual agent anti-HER2 therapy instead of monotherapy. In the metastatic setting, the antibody–drug conjugate trastuzumab deruxtecan is effective after progression on trastuzumab. Nivolumab and pembrolizumab, antibodies blocking the programmed cell death 1 (PD-1) receptor on T cells, have recently gained approval for clinical use in esophageal cancer patients for specific indications. Synergistic effects might be achieved with combinations of immune checkpoint inhibitors that target PD-1 on T cells or PD ligand 1 (PD-L1) on tumor cells and anti-cytotoxic T-lymphocyte-associated antigen 4 (CTLA-4) receptor on T cells. Multiple clinical trials investigating combinations of targeted and immunotherapies, with or without (neo)adjuvant chemo(radio)therapy, for curative and palliative treatment, are underway, and are expected to deliver a long-awaited improvement in the prognosis of esophageal cancer patients.