Antibody-Drug Conjugates in the Treatment of Esophageal Cancer

Abstract

Esophageal cancer remains one of the most lethal malignancies worldwide, with particularly poor outcomes following disease progression after first-line chemoimmunotherapy. Antibody-drug conjugates (ADCs) have emerged as a transformative therapeutic class that combines the targeting precision of monoclonal antibodies with potent cytotoxic payloads, enabling selective tumor cell killing while minimizing off-target toxicity. In the management of advanced esophageal cancer, I advocate for the integration of ADCs as a therapeutic option following progression on first-line chemoimmunotherapy. For patients with human epidermal growth factor receptor 2 (HER2)-positive gastroesophageal junction adenocarcinoma, trastuzumab deruxtecan is my preferred choice based on its superior overall survival benefit and robust bystander killing effect, which also confers activity in HER2-low tumors. For HER2-negative gastroesophageal adenocarcinoma, trophoblast cell-surface antigen 2 represents a promising target given its high prevalence of moderate to strong expression in nearly 80% of cases, and sacituzumab tirumotecan is currently under phase III investigation in this setting. In esophageal squamous cell carcinoma, I recommend biomarker-guided selection among ADCs targeting B7-H3, given its overexpression in over 90% of cases. For Nectin-4-expressing tumors, enfortumab vedotin may be considered as a later-line alternative despite modest activity. Notably, the bispecific ADC targeting both epidermal growth factor receptor and human epidermal growth factor receptor 3, BL-B01D1, has demonstrated compelling efficacy in immunotherapy-refractory esophageal squamous cell carcinoma, and I consider it a breakthrough option in this subtype. For claudin-18.2-positive gastroesophageal junction adenocarcinoma, several ADCs including CMG901, IBI343, and tecotabart vedotin represent promising later-line choices. I emphasize that patient selection should be guided by validated predictive biomarkers, and treatment decisions must account for distinctive toxicity profiles, particularly interstitial lung disease with trastuzumab deruxtecan. Finally, I strongly support advancing ADCs into earlier lines of therapy and perioperative settings through well-designed clinical trials to further improve long-term outcomes in this aggressive malignancy.