FDA approves Korlym for patients with endogenous Cushing’s syndrome
Today, Korlym (mifepristone) was approved by the U.S. Food and Drug Administration to control high blood sugar levels (hyperglycemia) in adults with endogenous Cushing’s syndrome. This drug was approved for use in patients with endogenous Cushing’s syndrome who have type 2 diabetes or glucose intolerance and are not candidates for surgery or who have not responded to prior surgery. Korlym should never be used (contraindicated) by pregnant women.
Prior to FDA’s approval of Korlym, there were no approved medical therapies for the treatment of endogenous Cushing’s syndrome.
Endogenous Cushing’s syndrome is a serious, debilitating and rare multisystem disorder. It is caused by the overproduction of cortisol (a steroid hormone that increases blood sugar levels) by the adrenal glands. This syndrome most commonly affects adults between the ages of 25 and 40. About 5,000 patients will be eligible for Korlym treatment, which received an orphan drug designation by the FDA in 2007.
Korlym blocks the binding of cortisol to its receptor. It does not decrease cortisol production but reduces the effects of excess cortisol, such as high blood sugar levels.
The safety and efficacy of Korlym in patients with endogenous Cushing’s syndrome was evaluated in a clinical trial with 50 patients. A separate open-label extension of this trial is ongoing. Additional evidence supporting the agency’s approval included several safety pharmacology studies, drug-drug interaction studies and published scientific literature. Patients experienced significant improvement in blood sugar control during Korlym treatment, including some patients who had marked reductions in their insulin requirements. Improvements in clinical signs and symptoms were reported by some patients.
The most common side effects experienced by endogenous Cushing’s syndrome patients treated with Korlym in clinical trials were nausea, fatigue, headache, arthralgia, vomiting, swelling of the extremities, dizziness and decreased appetite. Other side effects of Korlym include adrenal insufficiency, low potassium levels, vaginal bleeding and a potential for heart conduction abnormalities. Certain drugs used in combination with Korlym may increase its drug level. Health care professionals must be aware of the potential for drug-drug interactions and adjust dosing or avoid using certain drugs with Korlym.
Korlym should never be used by pregnant women. Although pregnancy is an extremely rare occurrence in Cushing’s syndrome patients because of the suppressive effect of excess cortisol on female reproductive function, Korlym will carry a Boxed Warning advising health care professionals and patients that the therapy will terminate a pregnancy.
The FDA has determined that a Risk Evaluation and Mitigation Strategy (REMS) is not necessary for Korlym to ensure that the benefits outweigh the risks for patients with endogenous Cushing’s syndrome. Several factors were considered in this determination including the following:
There are no other approved medical therapies for this debilitating form of Cushing’s syndrome and very sick patients would suffer if impediments to access were imposed.
The number of Cushing’s syndrome patients who will require treatment with Korlym is small, with an estimated 5,000 patients being eligible for treatment.
The number of health care professionals in the United States who would potentially prescribe Korlym is very small and highly specialized. They are familiar with the risks of Korlym treatment in the endogenous Cushing’s syndrome population and frequently monitor patient status.
The risks of Korlym treatment in the intended population can be managed through physician and patient labeling. The risks associated with Korlym will be outlined in a medication guide for patients.
The company has voluntarily proposed distributing Korlym through a central pharmacy to ensure the timely, convenient and appropriate delivery of the drug to Cushing’s patients or to the health care institutions where this therapy may be initiated. Most retail pharmacies are unlikely to keep adequate supplies of the drug for this rare condition and central distribution will give patients with Cushing’s syndrome better access to Korlym.
Korlym is manufactured by Corcept Therapeutics of Menlo Park, Calif.
The FDA, an agency within the U.S. Department of Health and Human Services, protects the public health by assuring the safety, effectiveness, and security of human and veterinary drugs, vaccines and other biological products for human use, and medical devices. The agency also is responsible for the safety and security of our nation’s food supply, cosmetics, dietary supplements, products that give off electronic radiation, and for regulating tobacco products.