Cushing's Disease: Long-Term Effectiveness and Safety of Osilodrostat in a Polish Group of Patients with Persistent Hypercortisolemia in the Experience of a Single Center

Osilodrostat is a potent oral steroidogenesis inhibitor that has emerged as the new medical agent for patients with Cushing's disease (CD) requiring long-term medical therapy for hypercortisolemia control. Its efficacy and safety have been assessed in clinical trials; however, real-world evidence is still scarce. This study aimed to investigate the long-term treatment (156 weeks) clinical and biochemical effect of osilodrostat in six patients with CD at a single center in Poland, initially participating in the LINC4 study. At week 36, all six patients met the key secondary endpoint of the LINC4 trial, achieving normalization of median urinary free cortisol. Osilodrostat treatment allowed for complete disease control in all patients and none of the patients was excluded due to the lack of treatment effectiveness in 156 weeks of follow-up. All patients demonstrated significant improvement from baseline on most metabolic and cardiovascular parameters, which was most evident at week 36 and sustained throughout the study period. This study supports and strengthens the role of osilodrostat as an effective long-term medical treatment in patients with CD. We also present three patient case histories in detail to highlight the clinical situations that endocrinologists might face during osilodrostat therapy.

What is the role of medical therapy in adrenal-dependent Cushing's syndrome?

Medical therapy to control hypercortisolism in adrenal Cushing's syndrome is currently not the first-line therapy. However, in many clinical scenarios like pre-surgical treatment, in patients who are not suitable candidates for surgery or in patients with bilateral hyperplasia, medical therapy can be important representing the only viable treatment option. Adrenal steroidogenesis inhibitors and glucocorticoid receptor blockers have been used for many years: metyrapone, ketoconazole and mifepristone are in current use and effective. Mitotane can be used as well but is considered second-line therapy because of its high toxicity. Etomidate has a special position as emergency medication in severe hypercortisolism. New drugs are tested in prospective trials (levoketoconazole, osilidrostat and relacorilant) and might become effective alternatives to common drugs. Oher drugs - adrenal steroidogenesis inhibitors as well as glucocorticoid receptor antagonists - are currently tested in vitro.

Low-dose etomidate for the management of severe hypercortisolaemia in different clinical scenarios: a case series and review of the literature

BACKGROUND

Severe Cushing's syndrome (SCS) is associated with acute cardiovascular, metabolic and infectious complications. It is considered an emergency, requiring an immediate diagnosis, together with a broad spectrum of supportive and hypocortisolaemic treatments. Surgical intervention, aimed at removing the source of cortisol or adrenocorticotropic hormone (ACTH), is the optimal treatment in most cases of Cushing's syndrome. However, in hypercortisolaemic states, surgical intervention has high rates of perioperative mortality and morbidity. Oral adrenal steroidogenesis inhibitors, even if more effective in combination, are not always efficient enough or well tolerated. Despite their common use, a more potent, parental, immediate, and thus life-saving, therapy is necessary.

METHODS

The authors present three different clinical scenarios of etomidate treatment in patients hospitalized in the third reference endocrinological centre in Poland between 2016 and 2017.

RESULTS

Patients with Cushing's disease, ectopic Cushing's syndrome and adrenocortical carcinoma presented with severe hypercortisolaemia and exacerbated cortisol-dependent comorbidities. In these three cases, etomidate acted as an accurate, well tolerated and effective cortisol-lowering drug for several days or even months. Patients were monitored in a general ward setting, and no side effects of the therapy were observed.

CONCLUSIONS

In doses far lower than those used for anaesthesia, etomidate works as a useful cortisol-lowering therapy in patients intolerant to or unable to take oral medications. Additionally, if urgent, the most potent and effective medical intervention is necessary, and clinicians should be aware of such a therapeutic option.