Cushing disease can cause abdominal stretchmarks, red cheeks, fatty hump between shoulders, pendulous abdomen and thin arms and legs.
Isturisa is the first FDA-approved drug that directly addresses the cortisol over-production characteristic of Cushing’s disease by blocking the enzyme, 11-beta-hydroxylase, and preventing cortisol synthesis. Cushing’s disease is a rare disease where the pituitary gland releases too much adrenocorticotropic hormone (ACTH). It is caused by a tumor or excess growth of the pituitary gland.
“The FDA supports the development of safe and effective treatments for rare diseases, and this new therapy can help people with Cushing’s disease, a rare condition where excessive cortisol production puts them at risk for other medical issues,” said Dr. Mary Thanh Hai, acting director of the Office of Drug Evaluation II in the FDA’s Center for Drug Evaluation and Research. “By helping patients achieve normal cortisol levels, this medication is an important treatment option for adults with Cushing’s disease.”
Isturisa was evaluated in a study of 137 adult patients with a mean age of 41 years. In the 24 week, open-arm, open-label period, patients received a starting dose of 2 mg of Isturisa twice a day that could be increased every two weeks up to 30 mg twice a day. At the end of the trial about half the patients had cortisol levels within normal levels. After this, 71 patients who did not need further dose increases and tolerated the drug for 12 weeks entered a withdrawal period for eight weeks. At this point, they either received Isturisa or a placebo.
The most common side effects in the clinical trial were adrenal insufficiency, headache, vomiting, nausea, fatigue and edema. Further side effects that may occur in people receiving this drug include, hypocortisolism, QTc prolongation and elevations in adrenal hormone precursors.</p>
The way the drug is administered is orally twice a day, one in the morning and the other in the evening. After the start of the treatment a revaluation may be conducted to alter the dosage, depending on the patient’s response.</p>