New Cushing’s disease treatment option reaches Canada with Isturisa
Therapy is for adults with high cortisol when surgery fails or isn’t possible
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Isturisa (osilodrostat) is now available in Canada for adults with Cushing’s disease who have persistent or recurrent high cortisol after pituitary surgery and/or pituitary irradiation, or who can’t have pituitary surgery, according to Recordati Rare Diseases Canada.
The oral medication is approved in the U.S. and the European Union for endogenous hypercortisolemia, or high cortisol caused by the body itself, in adults with Cushing’s syndrome when surgery isn’t an option or hasn’t been curative. Isturisa was developed by Novartis and then licensed to Recordati Rare Diseases.
“Isturisa is an important addition to the treatment options for Cushing’s disease, a rare and debilitating condition. Achieving control of cortisol overproduction is an important strategy in helping patients manage Cushing’s disease,” André Lacroix, MD, professor of medicine at the University of Montreal in Canada and an expert in Cushing’s syndrome, said in a company press release.
What Cushing’s disease is and why cortisol levels rise
Cushing’s disease is a form of endogenous Cushing’s syndrome caused by a pituitary tumor that triggers the body to make too much cortisol. Treatment is usually surgery to remove the tumor, but some people aren’t candidates for surgery or continue to have high cortisol afterward.
Isturisa works by blocking an enzyme involved in the final step of cortisol production. By lowering cortisol levels, it can help ease Cushing’s symptoms. The medication is available as film-coated tablets in 1 mg, 5 mg, or 10 mg strengths, allowing doctors to adjust dosing based on cortisol levels and how a patient responds.
Canada’s approval was supported by two Phase 3 studies, LINC-3 (NCT02180217) and LINC-4 (NCT02697734), which included a total of about 210 adults with Cushing’s disease who had persistent or recurrent high cortisol, including after pituitary surgery and/or pituitary irradiation or when surgery wasn’t an option. In LINC-3, patients first received Isturisa in an open-label period, and those who responded were later assigned to continue Isturisa or switch to placebo. In LINC-4, patients were initially randomized to Isturisa or placebo during a 12-week controlled period, followed by open-label treatment.
In LINC-3, 86% of patients who continued Isturisa maintained cortisol control, compared with 29% of those switched to placebo. In LINC-4, 77% of patients on Isturisa achieved normal cortisol levels after about three months, compared with 8% on placebo. By week 36 (about eight months), 81% had cortisol under control.
In the U.S., Isturisa was first approved for adults with Cushing’s disease, and its indication was expanded last year to include all forms of endogenous Cushing’s syndrome when surgery isn’t an option or hasn’t been curative. Real-world studies have also reported cortisol reductions, including normalization in some patients, in people treated with Isturisa.
