PMON165 Favorable Liver Safety Profile of the Selective Glucocorticoid Receptor Modulator Relacorilant in Healthy and Hepatically Impaired Adults and in Patients with Cushing Syndrome

Abstract Background Relacorilant is a highly selective glucocorticoid receptor (GR) modulator in development for the treatment of endogenous Cushing syndrome (CS). Unlike the FDA-approved GR antagonist mifepristone, relacorilant lacks affinity for the progesterone and other receptors. In a phase 2 study in patients with CS (NCT02804750, Pivonello et al, 2021), relacorilant provided clinically meaningful changes in a number of cortisol-excess-related comorbidities, including hypertension and hyperglycemia, without undesirable antiprogesterone effects or drug-induced hypokalemia. Currently, 4 clinical studies of relacorilant in patients with CS are ongoing: GRACE (NCT03697109), a phase 3 trial enrolling patients with endogenous CS of all etiologies; GRADIENT (NCT04308590), a phase 3 trial focusing on hypercortisolism due to adrenal adenomas or hyperplasia; a phase 2/3 long-term extension study (NCT03604198); and a phase 1b study in patients with adrenocortical carcinoma associated with glucocorticoid excess (NCT04373265). Here, we report safety results and liver function test (LFT) changes from open-label phase 1 and 2 studies of relacorilant in healthy and hepatically impaired adults and in adult patients with CS. Methods In a special population study, 9 subjects with moderate hepatic impairment (Child-Pugh Class B) and 9 matched controls with normal hepatic function received relacorilant (300 mg QD) for 10 days. In a phase 1 fixed-sequence drug-drug interaction study (NCT03512548), 28 healthy subjects received relacorilant (300 mg QD) for 10 days followed by 10 days of relacorilant (300 mg QD) combined with itraconazole (200 mg QD). Thirty-five patients with CS received relacorilant (100–400 mg QD) for up to 16 weeks in the phase 2 study. Results While relacorilant is eliminated primarily through the hepatic route, no apparent difference in relacorilant pharmacokinetics in subjects with moderate hepatic impairment vs matched controls was observed, with relacorilant exposures (as measured by area under the concentration-time curve [AUC] and maximum concentration [Cmax]) largely overlapping across both groups. In addition, reductions in LFTs were observed in this study. In healthy adults treated with relacorilant followed by relacorilant + itraconazole (an agent with reported liver toxicity), a similar trend toward reduced LFTs was seen throughout the study. In the phase 2 study in patients with CS, reductions in LFTs were also observed, including normalization of LFTs in some patients with abnormal values at baseline. Conclusions These results suggest that relacorilant has a favorable liver safety profile that includes a trend toward improved LFTs in volunteers and patients with normal and abnormal liver function. The findings of the hepatic impairment study support the use of relacorilant without dose adjustment in patients with moderate hepatic impairment. Presentation: Monday, June 13, 2022 12:30 p.m. - 2:30 p.m.