Abstract
Abstract CT116: A first-in-human phase 1 study on the safety, PK, receptor occupancy, and pharmacodynamic markers of SPX-303, a first-in-class LILRB2×PD-L1 bispecific antibody
Cancer research (Chicago, Ill.), Vol.85(8_Supplement_2), pp.CT116-CT116
04/25/2025
DOI: 10.1158/1538-7445.AM2025-CT116
Abstract
Background:
Leukocyte immunoglobulin-like receptor B2 (LILRB2) suppresses immune cell activation, particularly within myeloid cells in the tumor microenvironment (TME), while the PD-1/PD-L1 axis serves as a key immune checkpoint that inhibits T-cell function. SPX-303 is a novel bispecific antibody designed to simultaneously block LILRB2 and PD-L1, thereby revitalizing antitumor immune responses. Here, we present initial findings from the ongoing first-in-human Phase 1 trial of SPX-303 in patients with advanced solid tumors, including safety, pharmacokinetics (PK), and receptor occupancy (RO).
Methods:
This is an open-label, multicenter Phase 1 study for patients with advanced solid malignancies with 3+3 dose-escalation design, followed by an expansion cohort at the recommended Phase 2 dose (RP2D). SPX-303 is administered intravenously every three weeks and safety is assessed through CTCAE v5.0 criteria. Primary Objectives of this study are to determine the safety, tolerability, and RP2D of SPX-303. Secondary endpoints include antitumor activity as well as characterization of the PK and PD of SPX-303. This study is currently open and enrolling in escalation cohorts.
Details
- Title: Subtitle
- Abstract CT116: A first-in-human phase 1 study on the safety, PK, receptor occupancy, and pharmacodynamic markers of SPX-303, a first-in-class LILRB2×PD-L1 bispecific antibody
- Creators
- Justin MoserHao XieYujie ZhaoYousef ZakhariaDongdong LiBrandon WilliamDinh-Duc NguyenJack HoveyTiffany LiRobert CaiJichun MaJingdong QinMartin SiekierzyckiAnthony HaightHua JinWeiwei MaoKevin Bin LiGui-Dong Zhu
- Resource Type
- Abstract
- Publication Details
- Cancer research (Chicago, Ill.), Vol.85(8_Supplement_2), pp.CT116-CT116
- Publisher
- AMER ASSOC CANCER RESEARCH
- DOI
- 10.1158/1538-7445.AM2025-CT116
- ISSN
- 0008-5472
- eISSN
- 1538-7445
- Language
- English
- Date published
- 04/25/2025
- Academic Unit
- Hematology, Oncology, and Blood & Marrow Transplantation; Internal Medicine
- Record Identifier
- 9984822842502771
Metrics
1 Record Views