291. CLINICAL OUTCOMES OF IMMUNOCHEMOTHERAPY FOR UNRESECTABLE OR RECURRENT ESOPHAGEAL SQUAMOUS CELL CARCIONOMA

Abstract Background/Aim KEYNOTE-590 and CheckMate 648 study showed significantly feasible clinical outcomes in patients with advanced esophageal carcinoma. Herein, we report our clinical results of immunochemotherapy for unresectable and recurrent esophageal squamous cell carcinoma. Patients and Methods 17 patients who received pembrolizumab plus 5-fluorouracil and cisplatin (IO+C) and 9 patients who received nivolumab plus ipilimumab (IO+IO) were enrolled. Results The median age of the IO+C group was 70 years, and all patients had unresectable disease. A median of 2 courses of treatment were performed, and the best overall response rate was 68.6% including CR in 2 patients, PR in 9 patients, SD in 4 patients, PD in 1 patient and NE in 1 patient. One-year progression-free survival rate (PFS) was 36.1% and one-year overall survival (OS) was 64.6%. Immune-related adverse events (irAE) included liver damage in 4 patients, skin damage in 4 patients, thyroid dysfunction in 2 patients and lung damage in 1 patient. The median age of the IO+IO group was 79 years, with 3 patients of unresectable disease and 6 patients of recurrence. A median of 2 courses of treatment were performed, and the best overall response rate was 71.4% including CR in 4 patients, PR in 1 patient, SD in 1 patient, PD in 1 patient, and NE in 2 patients. One-year PFS was 68.6% and one-year OS was 85.7%. irAE included liver damage in 3 patients, skin damage in 6 patients, thyroid dysfunction in 2 patients, rhabdomyolysis in 1 patient and hypopituitarism in 1 patient. Discussion/Conclusion Currently, in our institute, IO+C is the first choice for unresectable esophageal carcinoma, and IO+IO is selected for patients who are unresponsive or intolerant to FP, patients requiring outpatient treatment and patients with recurrent disease. Although long-term clinical outcomes will need to be examined, immunochemotherapy is very useful and it is necessary to examine the effective use of IO+C and IO+IO in the future.