Cushing’s disease is caused by overproduction of cortisol, a hormone made by the adrenal glands. A tumor in the pituitary gland leads to overstimulation of the adrenal gland, which results in excess cortisol production. Cortisol regulates many important functions in the body, including response to stress and injury.
Patients with Cushing’s disease may experience increased weight, glucose intolerance or diabetes, high blood pressure, easy bruising, and increased risk for infections.
“Although surgery tends to be first line therapy to treat Cushing’s disease, Signifor is a new treatment option for patients when surgery hasn’t worked or isn’t an option,” said Mary Parks, MD, director of the Division of Metabolism and Endocrinology Products in the FDA’s Center for Drug Evaluation and Research.
The safety and effectiveness of Signifor were evaluated in a clinical trial of 162 Cushing’s disease patients. Trial participants were randomly chosen to receive one of two dose levels of Signifor over a six-month treatment period. Some patients who safely responded to the medication where allowed to continue treatment. Signifor resulted in decreased cortisol levels as measured in urine collected over a 24-hour period.
This reduction was seen as early as one month after starting treatment. About 20 percent of patients in the clinical trial were able to reduce urine cortisol levels into the normal range.
Signifor caused increases in blood sugar levels, which could be detected as early as two weeks after starting treatment. Continued treatment caused or worsened diabetes in some patients; therefore, patients need to be carefully monitored for this side effect and be treated appropriately with anti-diabetic therapies, including insulin.
The FDA is requiring three post-marketing studies for Signifor: a clinical trial to assess high blood sugar (hyperglycemia) management; a long-term prospective observational cohort study (registry) of patients with Cushing’s disease treated with Signifor; and focused safety monitoring for reports of serious hyperglycemia, acute liver injury, and adrenal insufficiency.
Signifor is administered under the skin (subcutaneously) twice daily, and will be dispensed with a Medication Guide, including instructions for patients and caregivers that describe the risks and adverse reactions people should be mindful of when using the product.
The most common adverse reactions observed in the clinical trial included hyperglycemia, diarrhea, nausea, abdominal pain and gallstones.
Signifor is manufactured by Novartis Pharma Stein AG, Stein, Switzerland.
Photo credit - Armin Kübelbeck