This is a first-in-human, Phase 1/2, multicenter, open-label study to evaluate the safety, PK, PDy, and preliminary anti-tumor activity of ARX517 in subjects with mCRPC who are resistant or refractory to standard therapies. Phase 1a and 1b dose-escalation and dose expansion stages will identify the MTD and/or RP2D(s). Phase 2 will randomize subjects to receive ARX517 at the RP2D(s) or ICT as comparator. The ICT to be used in Phase 2 will be determined after reviewing all available clinical data in Phase 1
A Phase 1/2, Multicenter, Open-label, Dose-escalation, and Dose-expansion Study to Evaluate the Safety, Pharmacokinetics, and Anti-tumor Activity of ARX517, with Randomized Comparison to Investigator's Choice of Treatment (ICT), in Subjects with Metastatic Castration-resistant Prostate Cancer who are Resistant or Refractory to Prior Standard Therapies