Osilodrostat for the Treatment of Cushing’s Disease: A Plain Language Summary of the LINC 4 Study

Abstract

What is this summary about? This is a summary of an article discussing the results of the LINC 4 study, which was originally published in the Journal of Clinical Endocrinology and Metabolism. The study included 73 adults with Cushing's disease who were treated with a drug called osilodrostat (also known by the brand name Isturisa®). What is Cushing's syndrome and Cushing's disease? Endogenous Cushing's syndrome is a condition whereby the body produces too much of the hormone cortisol due to different causes (pituitary tumour, adrenal tumour, and other tumours that produce adrenocorticotrophic hormone, a hormone that stimulates cortisol production). Cushing's disease is a specific type of Cushing's syndrome in which excess cortisol is caused by a tumour formed in the pituitary gland. People with Cushing's disease, compared with people without this condition, are at greater risk of other serious illnesses and early death, with signs and symptoms varying between individuals. Based on data from other studies, collectively called the LINC programme, osilodrostat is approved as a treatment taken by mouth for adults with Cushing's syndrome (in Europe, Switzerland and Japan), including Cushing's disease (in the USA). What happened in the LINC 4 study? The LINC 4 study looked at osilodrostat in 73 adult participants with Cushing's disease from 14 countries. The researchers wanted to learn how effective osilodrostat was in patients with Cushing's disease and what the side effects were. The term ‘side effect’ refers to any effect that a person experienced during the LINC 4 study. Side effects may or may not be caused by osilodrostat. What were the results? The study showed that osilodrostat was better than placebo (a dummy sugar pill) at lowering cortisol levels to normal, and that cortisol was then maintained at normal levels during continued treatment with osilodrostat through to week 48 of the study. In addition, signs and symptoms of Cushing's disease improved during treatment with osilodrostat, including lowered blood pressure, better control of blood sugar, and improved quality of life. The side effects of osilodrostat treatment were generally mild or moderate in severity, and very few study participants stopped taking the drug because of them. What do the results of the study mean? These results support osilodrostat as an effective medical treatment for people with Cushing's disease. Clinical Trial Registration: NCT02697734 ( ClinicalTrials.gov )