The U.S. Food and Drug Administration's approval is for treating unusually high production of a steroid hormone called cortisol, potentially leading to diabetes, high blood pressure and upper body obesity.
The condition affects about 20,000 people in the United States, mainly aged 20 to 50, and can be fatal if untreated, the company said. The drug blocks the binding of cortisol to its receptor.
However, Korlym's label will carry a boxed warning advising doctors and patients that the therapy will terminate a pregnancy.
Trading in Corcept shares, which closed at $3.03 on Friday on the Nasdaq, were halted at 16:12 ET after the FDA posted the approval at its website. However, the shares had risen 43 percent above their closing price by then.
Korlym, known generically as mifepristone, was approved as an orphan drug, meaning it treats a disease that affects fewer than 200,000 people in the United States. The designation comes with a seven-year marketing exclusivity period.
There are currently no drugs approved to treat the disease in the United States, although Novartis recently got the green light to sell its Cushing's treatment, Signifor, in Europe.
(Reporting by Anna Yukhananov in Washington and Anand Basu in Bangalore; Editing by Sreejiraj Eluvangal)
