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Isturisa
Published
Product name
Isturisa
Active ingredient
Osilodrostat phosphate
Submission type
New chemical entity
Decision
Approved
Decision date
Registration date
What this medicine was approved for
Isturisa (osilodrostat) was approved for the following therapeutic use:
Isturisa is indicated for the treatment of endogenous Cushing’s syndrome in adults.
How this medicine works
Osilodrostat is a cortisol synthesis inhibitor. It inhibits 11β hydroxylase (CYP11B1), the enzyme responsible for the final step of cortisol biosynthesis in the adrenal gland.
CYP11B1 inhibition is associated with the accumulation of precursors such as 11 deoxycortisol and acceleration of adrenal biosynthesis including androgens. In Cushing’s disease, the fall in plasma cortisol concentration also stimulates adrenocorticotropic hormone (ACTH) secretion, via the feedback mechanism which accelerates steroid biosynthesis (see section 4.8 Adverse effects (undesirable effects).
Why the TGA approved or did not approve this medicine
The decision was based on quality (chemistry and manufacturing), nonclinical (pharmacology and toxicology), clinical (pharmacology, safety and efficacy) and risk management plan information submitted by the sponsor. The benefit-risk profile of Isturisa was considered favourable for the therapeutic use approved.