Promising immunotherapies for esophageal cancer

ABSTRACT

Introduction: Esophageal cancer (EC) is the eighth most common cancer in the world, and the prognosis of EC is still poor. Although immunotherapy has been developed in melanoma and lung cancer, it is also expected to show efficacy in EC. Currently, several clinical trials are ongoing to evaluate the safety and efficacy of immunotherapies, immune checkpoint inhibitors, adoptive T cell transfer, and therapeutic cancer vaccines in EC.

Areas covered: This review provides an overview and the status of immunotherapy in EC. Clinical significance of molecules related immune checkpoints, especially PD-1 and PD-L1 is presented and the designs, results and future directions of clinical trials using immunotherapy in EC are provided.

Expert opinion: To bring immunotherapy to the forefront of treatment for EC, it is necessary to select patients who can obtain a high efficacy of immunotherapy and to also elucidate the correct timing for administration. Moreover, combination therapies of immunotherapy with existing chemotherapy or radiation or other immunotherapy with different mechanisms of action must be evaluated to achieve excellent outcomes in patients with EC.

KEYWORDS:

• Esophageal cancer
• immunotherapy
• immune checkpoint inhibitor
• CTLA-4
• PD-1
• PD-L1
• NY-ESO-1
• adoptive cell transfer
• therapeutic cancer vaccines

Article highlights

• Several clinical trials are ongoing to evaluate the safety and efficacy of immunotherapies, immune checkpoint inhibitors, adoptive T cell transfer, and therapeutic cancer vaccines in EC.

• The expression of PD-L1 in EC may be used as a biomarker to predict efficacy of immunotherapy using immune checkpoint inhibitors.

• Regarding immune checkpoint inhibitors, PD-1 or PD-L1 inhibitor may be promising immunotherapy in EC compared with CTLA-4 inhibitors based on clinical trials.

• It is important to select patients who can obtain the efficacy of immunotherapy and the timing when the best immunotherapeutic effects can be expected.

• Combination therapies of immunotherapy and existing anticancer therapy or other immunotherapy must be evaluated to achieve excellent outcomes in patients with EC.

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Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Additional information

Funding

This manuscript has not been funded.