• Histologically or cytologically confirmed prostatic adenocarcinoma without primary small cell histology

• Localized disease:

‣ Surgical resectability must be documented prior to enrollment

⁃ No evidence of distant metastatic disease on abdominopelvic imaging, bone imaging

• Enlarged lymph nodes below the iliac bifurcation (clinical stage N1) is allowed

∙ Either cross-sectional abdominopelvic imaging + technetium bone scan or PSMA PET imaging will be acceptable to rule out distant metastatic disease

• High or very high-risk disease (https://www.nccn.org/professionals/physician\_gls/pdf/prostate.pdf) as defined by having one or more of the following:

‣ Clinical T3a or higher

⁃ Histologic Grade Group 4 or 5

⁃ PSA \>20

• Eastern Cooperative Oncology Group performance status ≤ 1 (Appendix A)

• Total serum testosterone 100 ng/dL

• Patients must have normal hepatic function as defined below:

‣ Total bilirubin \<1.5 X the upper limit of normal (note that in subjects with Gilbert's syndrome, if total bilirubin is \>1.5 X ULN, measure direct and indirect bilirubin. If direct bilirubin is ≤1.5 X ULN, the subject may be eligible)

⁃ AST(SGOT)/ALT(SGPT) \<2.5 X institutional upper limit of normal

⁃ Albumin 3.0 g/dL

• Patients must have normal bone marrow function as defined below:

‣ Platelet count (plt) 100,000 /L

⁃ Hemoglobin (Hgb) 10 g/dL

⁃ Absolute neutrophil count (ANC) 1500

• Patients must have adequate renal function as defined below:

• • glomerular filtration rate (GFR) 30 mL/min

• Ability to understand and the willingness to sign a written informed consent document.

⁃ Patients with active diabetes mellitus on glucose lowering medications are eligible provided they agree to and are able to self-monitor daily blood glucose levels due to potential risk of lowering glucose levels on relacorilant.

⁃ Male patient and his female partner who is of childbearing potential must use 2 acceptable methods of birth control (one of which must include a condom as a barrier method of contraception) starting at screening and continuing throughout the study period and for 3 months after final study drug administration. Two acceptable methods of birth control thus include the following:

∙ Condom (barrier method of contraception) AND

‣ One of the following is required:

‣ Established use of oral, injected or implanted hormonal method of contraception by the female partner;

⁃ Placement of an intrauterine device (IUD) or intrauterine system (IUS) by the female partner;

⁃ Additional barrier method: Occlusive cap (diaphragm or cervical/vault caps) with spermicidal foam/gel/film/cream/suppository by the female partner;

⁃ Tubal ligation in the female partner;

⁃ Vasectomy or other procedure resulting in infertility (e.g., bilateral orchiectomy), for more than 6 months.