ASCO 2021: Immunotherapy shows promise in advanced esophageal squamous cell carcinoma

Article written by Bruce Sylvester.

Researchers report that both single and dual immunotherapy improve overall survival among patients with advanced esophageal squamous cell carcinoma, particularly those positive for the immune checkpoint protein PD-L1.

They presented these findings on June 3, 2021 at the American Society of Clinical Oncology/ASCO Virtual Annual Meeting 2021.

“Certain patients with advanced esophageal cancer, who currently have few treatment options, now stand to gain from immunotherapy. The dual immunotherapy combination of nivolumab and ipilimumab is the first chemotherapy-free first-line treatment showing benefit for these patients,” said ASCO Chief Medical Officer and Executive Vice President Julie R. Gralow, MD., professor of medical oncology and director of breast medical oncology at the University of Washington, Fred Hutchinson Cancer Research Center, in Seattle.

The purpose of CheckMate 648, a phase III study, was to determine survival among subjects with esophageal squamous cell carcinoma patients treated with nivolumab plus chemotherapy (cisplatin and 5-fluorouracil), nivolumab plus ipilimumab or chemotherapy only. 

As background, the authors noted that nivolumab has previously shown efficacy for improved survival among patients with advanced esophageal squamous cell carcinoma that is refractory or intolerant to previous chemotherapy. And combination of nivolumab/ipilimumab has shown clinical efficacy for several tumor types, suggesting that it might also be studied as a combination treatment for esophageal squamous cell carcinoma.

The investigators enrolled 970 subjects diagnosed with previously untreated, unresectable advanced, recurrent or metastatic esophageal squamous cell carcinoma.

The investigators randomized the subjects to treatment with nivolumab and chemotherapy, nivolumab and ipilimumab, or chemotherapy alone.

Primary endpoints were overall survival and progression-free survival in subjects with tumor cell levels of PD-L1 ≥ 1%.

Secondary endpoints included overall survival and progression-free survival in all randomized subjects.

Overall survival among subjects with PD-L1 ≥ 1%, was significantly better for those who received nivolumab plus chemotherapy and nivolumab plus ipilimumab when compared to chemotherapy only — 15.4, 13.7 and 9.1 months, respectively.

Overall survival was significantly better among subjects treated with nivolumab plus chemotherapy and nivolumab plus ipilimumab compared with chemotherapy alone — 13.2, 12.8, and 10.7 months, respectively.

Progression-free survival with nivolumab plus chemotherapy was significantly better than with chemotherapy alone among subjects with PD-L1 ≥ 1%.

“The clinically meaningful improvements in survival of these two treatment regimens highlight immunotherapy’s impact on cancer care and should bring new therapeutic options to a group of patients that are often diagnosed when disease has already spread,” said lead author Ian Chau, MD, FRCP, a consultant medical oncologist at the Royal Marsden Hospital in Sutton, United Kingdom.