1538P - A phase II study to evaluate the efficacy and safety of tislelizumab combined with chemotherapy (cis-platinum plus albumin-paclitaxel/paclitaxel) in neoadjuvant treatment of locally advanced oesophageal squamous cell carcinoma

Background

Neoadjuvant chemoimmunotherapy might benefit pts with locally advanced oesophageal squamous cell carcinoma (ESCC). Herein, we aimed to evaluate the efficacy and safety of Tislelizumab (a humanized anti-PD-1 antibody) combined with cisplatin plus albumin-paclitaxel(nab-PTX)/paclitaxel (PTX).

Methods

A prospective, open, single-arm, two-cohort phase II trial was conducted. ESCC Pts with resectable locally advanced disease were enrolled and randomly allocated into group nab-PTX (group A) or group PTX (group B). Pts received intravenous Tislelizumab (200 mg, day 1) combined with cisplatin (25mg/m2, day 1-3) plus nab-PTX (130 mg/m2, day 1, 8) in group A or PTX (75 mg/m2, day 1, 8) in group B of each 21-day cycle for two cycles before surgery, respectively. The primary endpoint was major pathologic responses (MPR) rate. The Secondary endpoints were pathological complete response (pCR) rate, R0 resection rate, treatment related adverse events (TRAEs), DFS and OS.

Results

From Feb 14, 2022, to Mar 8, 2023, 39 pts were enrolled (n=20 in group A, n=19 in group B). 35 pts received the full two-cycle chemoimmunotherapy successfully and received surgery (n=19 in group A, n=16 in group B), 2 pts in group B didn't receive the second cycle due to intolerance and dropped out, and 2 patients gave up surgery after neoadjuvant therapy for personal reasons (n=1 in each group). Pts underwent surgery within 23-97 days (median 35 days) after neoadjuvant treatment, among others, 2 pts delayed surgery due to TRAEs. All patients achieved radical (R0) resection. No patient died during neoadjuvant therapy and perioperative period. In group A, the MPR rate and pCR rate were 78.9% (15/19) and 36.8% (7/19), respectively. In group B, the MPR rate and pCR rate were 18.8% (3/16) and 0% (0/16), respectively. The most common TRAEs were lymphopenia (45.7%), diarrhoea (34.3.0%) and fatigue (31.4%), and there was no significant difference between groups.

Conclusions

Neoadjuvant treatment with Tislelizumab combined with cisplatin plus nab-PTX demonstrated promising anti-tumor efficacy with acceptable toxicity in pts with locally advanced thoracic ESCC.

Clinical trial identification

Editorial acknowledgement

Legal entity responsible for the study

Y. Sun.

Funding

BeiGene Pharmaceutical (Shanghai) Co., Ltd.

Disclosure

All authors have declared no conflicts of interest.