Phase 1 Open-Label Study of SPX-303, an Anti-LILRB2 and PD-L1 Bispecific Antibody, to Evaluate Safety and Effectiveness in Adults with Advanced Solid Tumors

What this Trial Is About

Researchers are evaluating SPX-303, a bispecific antibody targeting LILRB2 and PD-L1, in patients with advanced solid tumors who have progressed after prior treatments and are not eligible or decline other options. This open-label Phase 1 study aims to assess the safety, tolerability, pharmacokinetics, pharmacodynamics, and preliminary anti-tumor activity of SPX-303, including identifying the maximum tolerated dose or maximum administered dose. The study consists of two parts Part 1 is a dose escalation and safety expansion phase where SPX-303 is given intravenously every 3 weeks to patients with measurable disease. Part 2 focuses on dose expansion in specific solid tumor types using the recommended Phase 2 dose established in Part 1 to further evaluate anti-tumor activity. Both parts involve close monitoring of treatment effects and side effects. Participants will undergo regular visits for assessments including monitoring for dose-limiting toxicities, adverse events, response rates, disease control, progression-free survival, and drug levels in the body. Safety evaluations will continue for several years, with treatment-related adverse events tracked for up to 3.5 years. The study duration and follow-up periods vary by participant and study phase.

A Study of SPX-303, a Bispecific Antibody Targeting LILRB2 and PD-L1 in Patients With Solid Tumors