Investigating SX-682 in Combination With Apalutamide in Metastatic Castration-resistant Prostate Cancer

This study is testing whether combining SX-682 (an experimental drug that helps immune cells reach tumors) with apalutamide (a standard hormone-blocking drug) can improve outcomes for men with metastatic castration-resistant prostate cancer — prostate cancer that has spread and is no longer responding to hormone therapy. **You may be eligible if...** - You are 18 or older with confirmed metastatic castration-resistant prostate cancer - Your cancer has progressed after at least one prior next-generation anti-androgen drug (such as enzalutamide, apalutamide, or darolutamide) - You have measurable cancer progression on imaging or rising PSA - Tumor tissue is accessible for biopsy (required in phase 1) **You may NOT be eligible if...** - Your cancer has never been resistant to hormone therapy - You have not had prior treatment with a next-generation anti-androgen - You have major heart, liver, or kidney problems - You are not able to give consent or cooperate with the treatment schedule Talk to your doctor to see if this trial is right for you.