Envafolimab combined with albumin-bound paclitaxel and cisplatin in the neoadjuvant therapy for locally advanced esophageal squamous cell carcinoma: A prospective, single-arm, multicenter phase II study.

e16115 Background: Neoadjuvant chemoradiotherapy (nCRT) or neoadjuvant chemotherapy (nCT) followed by esophagectomy has been taken as the currently the standard of care for patients with locally advanced esophageal squamous cell carcinoma (LA-ESCC). However, both model were still limited by the relative high incidence of recurrence and poor prognosis. This phase II study aims to explore the efficacy and safety of a new neoadjuvant treatment combination of Envafolimab, Albumin-bound Paclitaxel and Cisplatin for LA-ESCC. Methods: This is a prospective, single-arm multicenter Phase II study. Eligible patients with pathologically confirmed ESCC and at clinical T1-3N1-3M0 or T3N0M0 stage according to the eighth edition of American Joint Committee on Cancer (AJCC) are included. The regimen includes 2 cycles of envafolimab subcutaneously at 300mg(d1), albumin-bound Paclitaxel Intravenously at 100mg/㎡ (d1 and d8), and cisplatin Intravenously at 75 mg/㎡(d1).The primary endpoint is pathological complete response (pCR) rate. Results: As of December 11, 2024, a total of 32 patients were included from four institutions in this study. Among them, 29 were male, and three were female. The median age of the patients was 64.5 years. Most patients(31/32,96.88%) finished two cycles neoadjuvant treatment. One patient occurred cerebral hemorrhage,and the other three patients chosed close observation rather than esophagectomy after two cycles neoadjuvant treatment. Total 28 patients underwent surgery, of which 9 patients achieved PCR (9/28,32.14%), 23 patients achieved at least major pathological response(MPR) (23 / 28, 82.14%), and other 5 patients did not achieve MPR. Conclusions: The combination of envafolimab, albumin-bound paclitaxel and cisplatindemonstrates promising pCR rate and acceptable tolerance in patients with LA-ESCC. The trial is ongoing, with further investigation anticipated. Clinical trial information: NCT05828381 .