Immunotherapy and Targeted Therapy for Advanced Gastroesophageal Cancer: ASCO Guideline Update

ASCO Guidelines provide recommendations with comprehensive review and analyses of the relevant literature for each recommendation, following the guideline development process as outlined in the ASCO Guidelines Methodology Manual. ASCO Guidelines follow the ASCO Conflict of Interest Policy for Clinical Practice Guidelines.Clinical Practice Guidelines and other guidance ("Guidance") provided by ASCO is not a comprehensive or definitive guide to treatment options. It is intended for voluntary use by clinicians and should be used in conjunction with independent professional judgment. Guidance may not be applicable to all patients, interventions, diseases, or stages of diseases. Guidance is based on review and analysis of relevant literature and is not intended as a statement of the standard of care. ASCO does not endorse third-party drugs, devices, services, or therapies and assumes no responsibility for any harm arising from or related to the use of this information. See complete disclaimer in Appendix 1 and Appendix 2 (online only) for more.

To provide updated recommendations for immunotherapy and targeted therapy for patients with advanced gastroesophageal cancer.

ASCO convened an Expert Panel to conduct a systematic review of relevant studies and develop recommendations for clinical practice.

Twelve newly published or updated phase III randomized controlled trials met the inclusion criteria for the systematic review.

The target population for these recommendations is patients with unresectable locally advanced, advanced, or metastatic gastroesophageal cancer. Results from testing for actionable biomarkers should be available as soon as possible to inform treatment decision making. Immunotherapy with doublet chemotherapy is recommended for patients with proficient mismatch repair (pMMR)/microsatellite stable (MSS) human epidermal growth factor receptor 2 (HER2)-negative gastroesophageal adenocarcinoma or squamous cell carcinoma and PD-L1 expression ≥1; patients with higher PD-L1 expression are more likely to benefit from immunotherapy. Zolbetuximab is recommended for patients with gastroesophageal adenocarcinoma, PD-L1 <1, and positive CLDN18.2 expression. Patients with dual PD-L1 and CLDN18.2 positivity should engage in shared decision making, considering the factors outlined in the guideline. Doublet chemotherapy alone is recommended for patients who are not positive for actionable biomarkers or are not considered candidates for targeted therapy or immunotherapy. For patients with pMMR/MSS HER2-positive gastric/gastroesophageal junction (GEJ) adenocarcinoma, trastuzumab and doublet chemotherapy is recommended; for patients with PD-L1 expression ≥1, the addition of pembrolizumab is recommended. Immunotherapy alone or with doublet chemotherapy is recommended for patients with mismatch repair deficient/microsatellite instability-high gastroesophageal cancer. Second-line therapy options include ramucirumab with paclitaxel, trastuzumab deruxtecan for HER2-positive gastric/GEJ adenocarcinoma, and immunotherapy for PD-L1 ≥1 esophageal squamous cell carcinoma after first-line combination chemotherapy without immunotherapy.Additional information is available at www.asco.org/gastrointestinal-cancer-guidelines.