Cushing's Disease

This trial will evaluate the effects of Lu AG13909 in adult participants with Cushing's disease (CD). CD is a rare and serious disorder where the body makes too much of a hormone called cortisol. The main goals of this trial are to learn about 1. the effect of Lu AG13909 on cortisol levels. 2. the safety and tolerability of Lu AG13909. 3. the pharmacokinetic parameters of Lu AG13909 (how the drug is absorbed, distributed, and processed by the body).

This study is designed as a single institution trial. The study utilizes safe and clinically-validated tools for preoperative workup of patients with small pituitary tumors. DDAVP stimulation and 18F-labeled fluoro-deoxyglucose (FDG) uptake for PET-imaging will be used to detect MRI-negative pituitary adenomas in patients with Cushing s disease. Patients who have MRI-negative pituitary microadenomas will undergo FDG PET-imaging with DDAVP stimulation. Intravenous FDG will be given approximately four hours following DDAVP administration. Within 12 weeks after completion of the FDG high-resolution PET scan, patients will undergo surgical resection of the pituitary adenoma. Surgical and histological confirmation of adenoma location will be noted. All images will be read independently by neuroradiologists blinded to clinical and histopathological outcomes. The diagnostic and localization accuracy of PET-imaging will be assessed by comparing the PET findings with histopathology.

The purpose of this study is to follow participants with Cushing's syndrome during the course of their routine care and to form a data registry to study long term participant outcomes.