Anti-LAG-3 antibody LBL-007 plus anti-PD-1 antibody toripalimab in advanced nasopharyngeal carcinoma and other solid tumors: an open-label, multicenter, phase Ib/II trial
Gang Chen, Dong-Chen Sun, Yi Ba, Ya-Xiong Zhang, Ting Zhou, Yuanyuan Zhao, Hong-Yun Zhao, Wenfeng Fang, Yan Huang, Zhen Wang, Chao Deng, Desheng Hu, W. Wang, Jinguan Lin, Guiling Li, Suxia Luo, Zhichao Fu, Haisheng Zhu, Huili Wang, Shengli Cai, Xiaoqiang Kang, Li Zhang, Yunpeng Yang
Abstract
PURPOSE: Open-label phase Ib/II study to investigate the safety and efficacy of LBL-007, an anti-LAG-3 antibody, plus toripalimab, an anti-PD-1 antibody, in patients with previously treated advanced nasopharyngeal carcinoma (NPC) and other solid tumors. METHODS: Patients with advanced tumors refractory to prior standard therapies were enrolled. In phase Ib, patients received LBL-007 200 mg or 400 mg and toripalimab 240 mg intravenously once every 3 weeks. In phase II, all patients received LBL-007 at the recommended phase II dose (RP2D) and toripalimab 240 mg intravenously once every 3 weeks. The primary end points were safety in phase Ib and objective response rate (ORR) in phase II. The exploratory end point was the predictive capability of LAG-3 and PD-L1 expression for efficacy. RESULTS: Between November 30, 2021, and December 1, 2023, 80 patients were enrolled, including 30 (37.5%) with NPC and 50 (62.5%) with other tumors. Median follow-up was 26.0 months. In Phase Ib, LBL-007 was administered at 200 mg to four patients and 400 mg to six patients, with no dose-limiting toxicities observed. Therefore, the 400 mg dose of LBL-007 was established as the RP2D and administered to 70 patients in phase II. Nine (11.3%) of 80 patients had grade 3 or 4 treatment-related adverse events, the most common of which included anemia (2.5%), hyponatremia (2.5%), increased alanine aminotransferase (2.5%), increased aspartate aminotransferase (1.3%), and fatigue (1.3%). Eight patients (10.0%) had treatment-related serious adverse events. No treatment-related deaths were reported. In immunotherapy-naive NPC patients (n = 12), ORR was 33.3%, disease control rate (DCR) was 75%, and median progression-free survival (PFS) was 10.8 months (95% CI, 1.3 to not estimated). In IO-treated NPC patients (n = 17), ORR was 11.8%, DCR was 64.7%, and median PFS was 2.7 months (95% CI, 1.4 to 4.9). For other tumors, ORRs were 15.8% in immunotherapy-naive patients and 3.7% in immunotherapy-treated patients. Patients with ≥ 2 + LAG-3 expression had a higher ORR of 28.0%, compared to 7.7% in those with < 2 + LAG-3 expression. CONCLUSION: LBL-007 plus toripalimab exhibited a manageable safety profile in patients with advanced solid tumors and demonstrated promising antitumor activity in NPC, especially in immunotherapy-naive patients. These findings warrant further validation in future studies.