Tislelizumab versus placebo combined with induction chemotherapy followed by concurrent chemoradiotherapy and adjuvant tislelizumab or placebo for locoregionally advanced nasopharyngeal carcinoma: Interim analysis of a multicenter, randomized, placebo-controlled, double-blind, phase 3 trial.

• DOI: 10.1200/jco.2024.42.16_suppl.6001
• Publication Date: 2024-06-10T16:18:50Z
• Authors: Hai-Qiang Mai; Sai Lan Liu; Qiu-Yan Chen; Lin-Quan Tang; Feng Jin; Ling Guo; Haiqing Luo; Ying Hu; Huai Liu; Jin-Hui Liang; Chong Zhao; Dong-Hua Luo; Hao-Yuan Mo; Shan-Shan Guo; Li-Ting Liu; Ji-Bin Li; Lin Wang; Xue-Song Sun; Xiao-Yun Li; Pan Wang
• Keywords: Interim analysis; Interim; Chemoradiotherapy; Induction chemotherapy; Adjuvant Chemotherapy

6001 Background: Patients with locoregionally advanced nasopharyngeal carcinoma (LANPC) have a risk of disease relapse after induction chemotherapy (IC)-concurrent chemoradiotherapy (CCRT). Early phase trials indicated that tislelizumab (PD-1 inhibitor) plus IC followed by CCRT the potential to deepen responses and extend survival in LANPC. Here, we report interim results 3 trial evaluate efficacy safety IC, adjuvant therapy Methods: high-risk LANPC (stage III-IVa, AJCC 8 th Staging System, excluding T3N0, T3N1 retropharyngeal lymph nodes +) were randomized (1:1) receive 200 mg or placebo + gemcitabine cisplatin (GP) every weeks (Q3W) for cycles, Q3W up an additional cycles. Stratification factors center stage (III IVa). Dual primary endpoints complete response rate (CRR) progression-free (PFS) per RECIST 1.1 investigator under blinded review. The planned analysis (IA) evaluating first endpoint, CRR, was scheduled at 4 completion test whether addition standard significantly improved allocated alpha 0.005. Results: Between June 2022, May 2023, 450 patients arm (n = 223) 227). Baseline characteristics balanced between two arms. At IA, 93.7% 93.8% completed cycles arm, respectively. Significant improvement CRR observed vs intent-to-treat population (ITT) (30.5% 16.7%; P 0.0006). Improvement consistent across key subgroups including [33.8% 20.7%]; IVa [28.7% 14.5%]), sex (male [28.3 % 15.7%]; female [38.0% 19.7%]), ECOG PS (PS 0 [28.8% 16.2%]; 1 [40.6% 19.4%]). ORR 93.3% 90.7% arm. In (tislelizumab n=219; n=224), incidence Grade ≥3 TEAEs (40.6% 39.3%) SAEs (2.3% 1.3%) similar Conclusions: met its endpoint statistically significant Induction GP generally well tolerated manageable profile. Continued follow-up is being conducted assess long-term safety. Clinical information: NCT05211232 .