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

This study is testing an experimental drug called SPX-303 — a bispecific antibody that targets two proteins (LILRB2 and PD-L1) involved in suppressing the immune system's ability to fight cancer. This is an early-phase trial to determine safety and effective dosing. **You may be eligible if...** - You are 18 or older - You have an advanced or metastatic solid tumor confirmed by biopsy - Your cancer progressed despite prior treatment and no standard options remain - You are in good general health (ECOG score 0 or 1) - You have at least one measurable tumor on imaging - Your heart, liver, kidney, and blood counts meet minimum requirements - People with well-controlled HIV may also be eligible **You may NOT be eligible if...** - You have uncontrolled or active autoimmune disease - You have untreated or unstable brain metastases - You have had certain serious immune reactions to prior checkpoint inhibitor therapy - You are pregnant or breastfeeding - You have a significant heart condition or abnormal heart rhythm Talk to your doctor to see if this trial is right for you.