Induction chemotherapy followed by concurrent chemoradiotherapy combined with toripalimab and Endostar in high-risk locally advanced nasopharyngeal carcinoma: A multicenter, randomized, phase 2 trial.

Abstract

6086 Background: Even though induction chemotherapy (IC) followed by concurrent chemoradiotherapy (CCRT) can improve the survival rate of patients with locally advanced nasopharyngeal carcinoma (LA-NPC), the recurrence and/or metastasis rates for patients with stage IV (T4 and/or N3) diseases remain high. This study investigates the efficacy and safety of adding Toripalimab (PD-1 inhibitor) and Endostar (recombinant human endostatin) to IC-CCRT in patients with high-risk LA-NPC. Methods: High-risk LA-NPC patients were randomly divided (1:1) into either the IC-CCRT+TE group (gemcitabine and cisplatin induction chemotherapy followed by concurrent chemoradiotherapy combined with Toripalimab and Endostar) or the IC-CCRT group (gemcitabine and cisplatin induction chemotherapy followed by concurrent chemoradiotherapy). Toripalimab (240mg, d1) was administered intravenously every 3 weeks for up to 12 cycles (3 induction, 2 concurrent, and 7 adjuvant). Endostar (7.5mg/m2, d1-10) was continuously injected intravenously every 3 weeks for a total of 5 cycles (3 induction and 2 concurrent). The primary endpoint was 3-year progression-free survival (PFS), and the secondary endpoints included 3-year overall survival (OS), 3-year locoregional relapse-free survival (LRFS), 3-year distant metastasis-free survival (DMFS), objective response rate (ORR) and safety. Results: From September 7, 2020, to August 23, 2022, a total of 106 eligible patients were randomly assigned to the IC-CCRT+TE group (n = 53) and IC-CCRT group (n = 53). At a median follow-up of 25 months, the PFS was significantly improved in the IC-CCRT+TE group compared to the IC-CCRT group (HR=0.36, p=0.041). 28 patients (52.8%) in the IC-CCRT+TE group and 5 patients (9.4%) in the IC-CCRT group achieved complete response (CR) after induction chemotherapy, and the difference was statistically significant (P < 0.001). The incidence of grade ≥3 acute adverse events in the IC-CCRT+TE group and IC-CCRT group was 66.0% and 62.3%, respectively. The incidence of grade ≥3 late adverse events in two groups was 5.8% and 5.7%, respectively. The incidence of grade ≥3 immune-related adverse events was only 4.7%. Conclusions: IC-CCRT combined with Toripalimab and Endostar significantly improved PFS in patients with high-risk locally advanced nasopharyngeal carcinoma, and the adverse events are manageable. Clinical trial information: NCT04447326 .