Study on ARV-766 Taken Orally in Men with Metastatic Prostate Cancer

Inclusion Criteria

• Confirmed diagnosis of prostate cancer.
• Currently receiving hormone therapy to lower testosterone levels or have had surgery to remove the testicles.
• Good overall health with an ECOG performance status of 0 or 1, meaning fully active or restricted in physically strenuous activity but ambulatory.

Part A:

• Cancer has progressed after at least two previous treatments for metastatic prostate cancer, including one second-generation hormone therapy like abiraterone or enzalutamide.
• Cancer is resistant to hormone therapy.

Part B:

• Have used one to three second-generation hormone therapies like enzalutamide or abiraterone.
• Have had no more than two chemotherapy treatments.
• Cancer is resistant to hormone therapy.

Part C & D:

• Have prostate cancer that is either resistant or sensitive to hormone therapy and has spread to other parts of the body, as shown by scans.

Exclusion Criteria

Part A and B:

• Have brain cancer that requires steroid treatment.
• Have active digestive issues like chronic diarrhea or have had certain stomach surgeries.
• Have had radiation therapy within 4 weeks before starting the study drug or radiation to more than 25% of the bone marrow.
• Have taken an experimental drug within 4 weeks before starting the study.
• Have had cancer treatment within 2 weeks before starting the study, except for hormone therapy to maintain low testosterone levels. For certain drugs like bicalutamide, mitomycin C, or nitrosoureas, the waiting period is 6 weeks, and for abiraterone, it's 4 weeks.

Part C and D:

• Have previously been treated with a second-generation hormone therapy.