Efficacy and safety of IBI351 (fulzerasib) monotherapy in KRASG12C inhibitor-naïve Chinese patients with KRASG12C-mutated metastatic colorectal cancer: a pooled analysis from phase I part of two studies
Ying Yuan, Yanhong Deng, Yongdong Jin, Zengqing Guo, Yueyin Pan, Cunji Wang, Zhiwu Wang, Yi Hu, Dong Hua, Xiangjiao Meng, Zhiye Zhang, Mingfang Zhao, Xiaorong Dong, Dingzhi Huang, Xiaoyan Li, Lian Liu, Meili Sun, Huijuan Wang, Xiuwen Wang, Nong Yang, Mingjun Zhang, Sheng Hu, Dongde Wu, Jingjing Huang, Sujie Zhang, Mengna Huang, Kefeng Ding
Abstract
Abstract IBI351 (also known as fulzerasib or GFH925), an irreversible covalent inhibitor of KRAS G12C , has demonstrated promising anti-tumour activity in patients with solid tumours. In this study, data were pooled from the phase I part of two clinical studies (NCT05005234 and NCT05497336), aiming to evaluate the efficacy and safety of IBI351 monotherapy in KRAS G12C inhibitor-naïve Chinese patients with KRAS G12C -mutated metastatic colorectal cancer (CRC). The objective response rate (ORR) was the primary endpoint. Secondary endpoints included disease control rate (DCR), progression-free survival (PFS), and overall survival (OS). As of December 13, 2023, 56 patients treated with IBI351 monotherapy were included. The median duration of treatment was 7.7 months (range: 0.3–16.7). The confirmed ORR was 44.6% (95% CI: 31.3–58.5), with a DCR of 87.5% (95% CI: 75.9–94.8). With a median follow-up of 13.8 months, the median PFS was 8.1 months (95% CI: 5.5–13.8). The median OS was 17.0 months (95% CI: 12.6–not reached). Treatment-related adverse events (TRAEs) occurred in 53 patients (94.6%), with grade 3 TRAEs in 14 patients (25.0%). No grade 4 or 5 TRAEs were observed. The most common grade 3 TRAEs were anaemia ( n = 4, 7.1%) and gamma-glutamyltransferase increased ( n = 3, 5.4%). TRAEs led to dose interruption in 12 patients (21.4%) and dose reduction in six patients (10.7%). No TRAEs resulted in treatment discontinuation. IBI351 demonstrated encouraging clinical efficacy and a manageable safety profile in KRAS G12C inhibitor-naïve Chinese patients with KRAS G12C -mutated metastatic CRC.