Study on Abiraterone Acetate and Prednisone With or Without Abemaciclib for Prostate Cancer

Inclusion Criteria

• Have a confirmed diagnosis of prostate cancer.
• The cancer has spread to other parts of the body, as shown by bone scans or imaging tests like CT or MRI.
• The cancer is progressing despite ongoing hormone therapy or after surgical removal of the testicles, shown by:
  • Rising PSA levels
  • Tumor growth seen on scans
• Have good organ function.
• Be in good overall health with an ECOG performance status of 0 or 1, meaning fully active or restricted in physically strenuous activity but ambulatory.

Exclusion Criteria

• Have previously taken drugs that inhibit CYP17.
• Have previously been treated with abemaciclib or similar drugs that target CDK 4 & 6.
• Have received chemotherapy for prostate cancer that is resistant to hormone therapy, except for certain cases.
• Have had specific treatments like radiopharmaceuticals or certain medications for prostate cancer.
• Have had radiation or surgery to all cancer sites being measured.
• Are currently participating in another clinical trial with an investigational drug.
• Have digestive issues that affect the absorption of medication or difficulty swallowing large pills.
• Have significant heart disease, active or chronic liver disease, or moderate to severe liver impairment.