First-in-class PD-1/IL-2 bispecific antibody fusion protein IBI363 in patients with advanced colorectal cancer: Safety and efficacy results from a phase I study.

• DOI: 10.1200/jco.2024.42.16_suppl.3593
• Publication Date: 2024-06-17T14:13:05Z
• Authors: Yiwen Chen; Xinjun Liang; Yu Chen; Hui Wang; Yuping Sun; Yueyin Pan; Jian Zhang; Jiuwei Cui; Qian Chu; Guang-Hai Dai; Liang Kang; Huiwen Ma; Jianzhen Shan; Weijia Fang; Yu-Long Zheng; Nong Xu; Weiqin Jiang; Cong Wei; Li Zhao; Tingbo Liang
• Keywords: 03 medical and health sciences; 0302 clinical medicine

3593 Background: The prognosis of advanced colorectal cancer (CRC) is poor with limited treatment options available. IBI363 a PD-1/IL-2 α-bias bispecific antibody that specifically activate PD-1(+)CD25(+) tumor specific T cells while sparing PD-1(-)CD25(-) bystander cells, and peripheral regulatory to protect the body from autoimmunity. Herein, we report safety efficacy in patients (pts) CRC phase I study. Methods: Eligible pts locally or metastatic who failed intolerant standard were enrolled received intravenously at dose levels ranging 100 ug/kg 3 mg/kg every week (QW), two weeks (Q2W) three (Q3W). primary endpoint was safety. secondary endpoints included objective response rate (ORR), disease control (DCR), duration (DoR), etc. per RECIST v1.1. Results: As December 22, 2023, total 68 (males: 55.9%, median age: 55.5 years, ECOG PS 1: 50.0%, liver metastasis: 61.8%; previous ≥3 lines: 76.5%; immunotherapy: 27.9%) recruited including 26 600 µg/kg Q2W 22 1 Q2W. Microsatellite stable (MSS)/proficient mismatch repair (pMMR) presented 57 (83.8%) microsatellite status remaining 11 (16.2%) unknown. Median follow up time 5.3 months (95%CI: 4.4-6.9). Treatment emergent adverse events (TEAEs) reported 65 (95.6%) grade TEAEs (32.4%) pts. Common (≥20%) arthralgia (35.3%), anemia (32.4%), pyrexia (22.1%) hypoalbuminemia (20.6%). related (TRAEs) 62 (91.2%) TRAEs 16 (23.5%) Immune (irAEs) irAEs 4 (5.9%) Serious TRAE 12 (17.6%) leading interruption discontinuation 25 (36.8%) 2 (2.9%) No death reported. Pts least post-baseline assessment evaluable set. In all (n=63), overall ORR 12.7% 5.6-23.5). metastasis (n=38), 13.2% 4.4-28.1). PD-L1 CPS ≥1 (n=13), 30.8% 9.1-61.4), DCR 76.9% 46.2-95.0). DoR not reached. A prospective cohort has been initiated. Further details data will be updated meeting. Conclusions: showed acceptable tolerability manageable profiles CRC. Preliminary observed, particularly ≥1. Clinical trial information: NCT05460767 .