⁃ Phase I Inclusion Criteria

• Willingness and ability to give informed consent.

• Agree to comply with all study procedures and attend all study visits.

• Male aged \>=40 years.

• History of prostate cancer diagnosis: Subjects with treated prostate cancer are eligible. Prior prostate cancer treatments must be clearly defined. Acceptable treatment modalities include surgery, radiation therapy, and previous use of antiandrogen therapy. Subjects with localized prostate cancer in low-risk group who were not on treatment or declined any treatment are eligible. Subjects with localized prostate cancer in the favorable intermediate-risk group who declined any treatment are eligible.

• Subjects must not be undergoing concurrent radiation therapy or androgen deprivation therapy (ADT) at the time of enrollment.

• ECOG performance status 0-2.

• Subjects must have normal liver and kidney function at baseline: Total bilirubin within normal institutional limits. AST(SGOT)/ALT(SGPT) \< 2.5 X upper limit of normal (ULN). Creatinine \< 1.5 ULN or creatinine clearance \> 50 mL/min/1.73 m2. Adequate bone marrow function: Hgb ≥ 9.0 g/dL, Platelets ≥ 100 x 109/L, absolute neutrophil count of ≥ 1.0 x 109/L).

• Subjects and their partners must agree to use two medically accepted methods of contraception and must agree to continue use these methods during the trial and for at least one week after the last dose of study drug. Acceptable methods of contraception include abstinence, barrier method with spermicide, intrauterine device (IUD) known to have a failure rate of less than 1% per year, or steroidal contraceptive (oral, transdermal, implanted, or injected) in conjunction with a barrier method. Periodic abstinence (e.g., calendar, ovulation, symptothermal, post ovulation methods) withdrawal, spermicides only, or lactational amenorrhea are not acceptable methods of contraception.

• Subjects taking strong inhibitors or inducers of CYP3A4 or CYP2C19 must be evaluated for potential drug interactions with the study drug. Essential medications, such as statins, that cannot be discontinued may be allowed at the investigator's discretion.

• Subjects currently taking herbal supplements containing AGN extract, such as Cogni.Q, Decursinol-50, Ache Action, Fast-Acting Joint Formula, must discontinue these or any other supplements containing these products at least 4 weeks prior to starting study drug.

⁃ Phase II Inclusion Criteria

• Willingness and ability to give informed consent.

• Agree to comply with all study procedures and attend all study visits.

• Male aged \>=40 years.

• Histologically confirmed adenocarcinoma of prostate (neuroendocrine or small cell prostate cancer excluded).

• Any T stage, N0-1, M0, any Gleason grade.

• Subjects must meet one of the following: Post-radical prostatectomy (RP) and/or post-radiation therapy (RT), including those with local recurrence declining further treatment. Localized prostate cancer who declined any treatment after physician discussion.

• No distant metastases disease confirmed by imaging (CT or MRI and bone scan or prostate-specific PET scan such as PSMA PET scan or Axumin PET scan) within 5 years prior to enrollment.

• Blood PSA level rising over 2 consecutive tests within the past 6 months, at least one week apart.

• Not currently receiving concurrent androgen deprivation therapy, and testosterone levels should be within a non-castrate range (\>50 ng/dL).

• ECOG performance status 0-2.

• Subjects must have normal liver, kidney, and bone marrow function at baseline: Total bilirubin within institutional limits. AST(SGOT)/ALT(SGPT) \< 2.5 X upper limit of normal (ULN). Creatinine \< 1.5 ULN or creatinine clearance \> 50 mL/min/1.73 m2. Adequate bone marrow function: Hgb ≥ 9.0 g/dL, Platelets ≥ 100 x 109/L, absolute neutrophil count ≥ 1.0 x 109/L.

• No evidence of any active secondary malignancy requiring ongoing treatment.

• Subjects must agree to use two medically accepted method of contraception and must agree to continue use this method while on the trial and through at least one week after the last dose of study drug. Acceptable methods of contraception include abstinence, barrier method with spermicide, intrauterine device (IUD) known to have a failure rate of less than 1% per year, or steroidal contraceptive (oral, transdermal, implanted, or injected) in conjunction with a barrier method. Periodic abstinence (e.g., calendar, ovulation, symptothermal, post ovulation methods) withdrawal, spermicides only, or lactational amenorrhea are not acceptable methods of contraception.

• Subjects taking strong inhibitors or inducers of CYP3A4 or CYP2C19 will be evaluated for potential drug interactions with the study drug. Essential medications, such as statins, that cannot be discontinued may be allowed at the investigator's discretion.

• Subjects currently taking herbal supplements containing AGN extract, including Cogni.Q, Decursinol-50, Ache Action, Fast-Acting Joint Formula, must discontinue these or any other supplements containing these products at least 4 weeks prior to starting study drug.