An Extension Study of CORLUX in the Treatment of Endogenous Cushing's Syndrome

Inclusion Criteria:

• Have completed the Week 24 visit and the 6-Week Follow-up visit of Corcept Study C-1073-400.
• In the opinion of the Investigator, are expected to maintain clinical benefit from mifepristone.
• Women of childbearing potential have a negative serum pregnancy test at Entry.
• Women of childbearing potential must be willing to use non-hormonal, medically acceptable methods of contraception during the study.
• Are able to provide written informed consent
• Are able to return to the investigative site to complete the study evaluations outlined in the protocol.
• Will not use systemic estrogens during the study.

Exclusion Criteria:

• Have an acute or unstable medical problem, which could be aggravated by mifepristone treatment.
• Are taking medications within 14 days of the Entry visit that a) have a large first pass metabolism that is largely mediated by CYP3A4 and which have a narrow therapeutic margin; and/or b) are strong CYP3A4 inhibitors.
• Female patients of reproductive potential, who are pregnant or who are unable or unwilling to use medically acceptable, non-hormonal methods of contraception during the study.
• Have received investigational treatment (drug, biological agent or device) other than CORLUX (mifepristone) within 30 days of Entry
• Have a history of an allergic reaction or intolerance to CORLUX (mifepristone)
• Have uncorrected hypokalemia (potassium level of <3.5 mEq/L) at Entry. Spironolactone or eplerenone is allowed to control hypokalemia.
• Postmenopausal women with a history of endometrial hyperplasia with atypia or pathological features consistent with endometrial carcinoma.
• Thickened endometrium on the Entry Visit transvaginal ultrasound that has not resolved after induction of menstrual bleeding with progesterone.
• Uncontrolled, clinically significant hypothyroidism or hyperthyroidism.
• Any woman with an intact uterus who has a hemorrhagic disorder or is being treated with an anticoagulant (e.g. warfarin, heparin).
• Have renal failure as defined by a serum creatinine of ≥2.2 mg/dL.
• Elevated total bilirubin >1.5 ULN, elevated ALT or AST ≥3X the upper limit of normal.