RecruitingPhase 1Drug trialA Phase 1 Study in Patients With Metastatic Castration-Resistant Prostate CancerThe goal of this clinical trial is to find out if FX-111 is safe enough to permit further studies in adult male participants with metastatic castration-resistant prostate cancer (mCRPC). It will also study the drug's pharmacokinetics (how the body breaks down FX-111) and how well FX-111 treats mCRPC. The main questions it aims to answer are: What are the side effects of FX-111? Does FX-111 work to reduce or prevent progression of mCRPC? The study doctor will oversee participants' treatment with FX-111 and ask about any side effects. Participants will take FX-111 every day by mouth and will have regular physical and laboratory examinations to check health and tumor status.