A Study to Assess the Safety and Efficacy of Levoketoconazole in the Treatment of Endogenous Cushing's Syndrome.

INCLUSION CRITERIA: SONICS STUDY COMPLETERS: Completed the final SONICS visit (M12) and have demonstrated maintenance of clinical response on a stable Therapeutic Dose of levoketoconazole for at least 12 weeks prior to study entry. ALL OTHERS: * Confirmed newly diagnosed, persistent or recurrent endogenous Cushing's syndrome of any etiology, except secondary to malignancy (including pituitary or adrenal carcinoma). * Elevated mean 24-hour Urinary Free Cortisol (UFC) levels at least 1.5X upper limit of the normative range of the study's central laboratory assay and from a minimum of three measurements from adequately collected urine. * Presence of abnormal values from at least one of these two diagnostic tests: * Abnormal Dexamethasone Suppression Test (DST) OR * Elevated late night salivary cortisol concentrations (at least two measurements) each greater than the upper limit of the study's central laboratory normative range * Non-candidates for CS-specific surgery, refuse surgery or surgery will be delayed until after study completion and agree to complete this study prior to surgery. * If post-surgical for CS-specific surgery, then no significant post-operative sequelae remain and the risk of such sequelae is considered negligible. EXCLUSION CRITERIA: Subjects will be excluded from the study if ANY of the following criteria are met (NOTE: exclusion criteria apply to and must be assessed in both cohorts): * Enrolled in SONICS but have not completed SONICS through …