Multicenter phase II study of trifluridine/tipiracil for esophageal squamous carcinoma refractory/intolerant to 5-fluorouracil, platinum compounds, and taxanes: the ECTAS study.

BACKGROUND: The standard treatment for unresectable advanced/recurrent esophageal cancer in Japan is 5-fluorouracil plus platinum-containing drugs as first-line chemotherapy and taxanes as second-line chemotherapy. However, the standard regimen after patients become refractory to these treatments remains to be established. Therefore, we investigated the efficacy of trifluridine/tipiracil (FTD/TPI) in patients with esophageal cancer who are refractory or intolerant to 5-fluorouracil, platinum-containing drugs, and taxanes. METHODS: This single-arm phase II trial was conducted in seven hospitals in Japan. Eligible patients were those with unresectable advanced/recurrent esophageal cancer that was refractory or intolerant to 5-fluorouracil, platinum-containing drugs, and taxanes. The primary endpoint was the 3-month progression-free survival rate, and the secondary endpoints were the 6-month progression-free survival rate, progression-free survival, overall survival, response rate, disease control rate, and toxicity. RESULTS: Forty-two patients were enrolled between October 2015 and June 2016. All tumors were squamous cell carcinomas. The progression-free survival rates at 3 and 6 months were 15.4% (90% confidence interval 7.4-26.0%) and 7.7% (90% confidence interval 2.6-16.6%), respectively. The median progression-free survival and median overall survival were 1.3 (95% confidence interval 1.0-1.8) months and 4.5 (95% confidence interval 3.6-5.7) months, respectively. The response rate was 0%, and the disease control rate was 23.8% (95% confidence interval 13.5-38.5%). The major grade 3/4 toxicities were neutropenia (47.6%), leukocytopenia (35.7%), and anemia (21.4%). No treatment-related deaths occurred. Exploratory subgroup analyses showed better progression-free survival in the subgroup without distant metastasis at diagnosis. CONCLUSIONS: Trifluridine/tipiracil monotherapy is feasible and shows modest activity in patients with refractory esophageal squamous cell carcinoma.