FDA

Isturisa approval expanded to include adults with Cushing syndrome

April 18, 2025

FDA approved the supplemental new drug application (sNDA) for Isturisa (osilodrostat) for the treatment of endogenous hypercortisolemia in adults with Cushing’s syndrome for whom surgery isn’t an option or hasn’t been curative.

Osilodrostat is a cortisol synthesis inhibitor that inhibits 11-beta-hydroxylase (CYP11B1), the enzyme responsible for the final step of cortisol biosynthesis in the adrenal gland.

Efficacy

According to the manufacturer, approval of the expanded indication was supported by data from a clinical development program that included over 350 patients (LINC6; NCT05382156). The primary endpoint was incidence of osilodrostat-related adverse events (AEs) and serious AEs. Secondary endpoints include change in mean urinary free cortisol (mUFC), serum cortisol and late-night salivary cortisol (LNSC). At 3 months, normalization of mUFC, serum cortisol and LNSC was observed in 71.4%, 69.2%, and 50% of patients, respectively.

Safety

The most common (≥5%) AEs in the trial were asthenia and vomiting (both 5.5%); treatment-related AEs with highest frequency were vomiting and dizziness (both 9.1%).

Sources:

Isturisa (osilodrostat) [package insert]. Recordati. https://www.recordatirarediseases.com/sites/www.recordatirarediseases.com/files/inline-files/Isturisa-Prescribing-Information-Current.pdf Revised April 2025. Accessed April 17, 2025.

FDA grants Isturisa® (osilodrostat) expanded indication for the treatment of endogenous hypercortisolemia in patients with Cushing’s syndrome. [News release]. 2025. https://d2e3isjppdvvam.cloudfront.net/wp-content/uploads/2025/04/16063430/Press-Release_Isturisa-CS-approval.pdf

Bancos I, et al. (2024, October 5). J Endocrine Soc. 7790 A Non-interventional, Multinational, Phase IV Study to Evaluate the Long-Term Safety and Efficacy of Osilodrostat in Patients with Endogenous Cushing's Syndrome (LINC 6): 1-Year Real-World Interim Analysis. https://academic.oup.com/jes/article/8/Supplement_1/bvae163.1098/7812387