Nevin, S

Abstract Disclosure: S.R. Chacko: None. C. Powell: None. B. Ndovu: None. E.Y. Ferreira: None. R. Rosenberg: None. J. Saini: None. S. Nevin: None. K. Yu: None. V. Fell: None. J.J. Larson: None. E. Atkinson: None. I. Bancos: Funding for investigator-initiated research from Esteve. Context: Mild autonomous cortisol secretion (MACS), found in about 50% of patients with adrenal incidentalomas, is associated with increased cardiovascular morbidity. While adrenalectomy improves outcomes in unilateral MACS, safe and effective medical therapy is needed for bilateral MACS. Objectives: To evaluate the tolerability and safety of overnight metyrapone in adults with MACS. Methods: Study design: Open-Label, Phase 2, Clinical Trial (NCT06106295) Participants: Patients >18-years-old with MACS and benign adrenal imaging phenotype were prospectively enrolled between December 2023 and January 2025. MACS was diagnosed based on 1 mg post-dexamethasone suppression test serum cortisol >1.8 mcg/dL. Eligibility required at least one MACS-associated comorbidity (obesity, dysglycemia, dyslipidemia, hypertension, osteopenia or osteoporosis). Intervention: Metyrapone was administered at an initial dose of 250 mg each evening with up titration in 250 mg increments every 2-4 weeks based on tolerance, to a maximum of 1000 mg. Outcomes: The primary endpoint was assessment of treatment-related adverse events (AE), categorized by CTCAE grade. Adrenal insufficiency (AI) was considered an AE, assessed on biochemistry and AddiQoL survey. Sample size: 30 patients projected Results: Twenty-six patients with MACS [median age 66 years (IQR 61-68), 69% women] were enrolled. At the time of analysis, median metyrapone dose was 1000 mg (IQR 750-1000). At median follow-up of 3 months (IQR 2-6), 22 patients (85%) developed at least one AE. None were serious, aside from one patient with an acute kidney injury (AKI), unlikely related to metyrapone. All other AEs were CTCAE Grade 1-2, including dizziness 12%, nausea 6% and fatigue 5%. Of all 90 AEs, 12 (13%) occurred at a dose of 250 mg, 10 (11%) at 500 mg, 20 (22%) at 750 mg and 48 (53%) at 1000 mg. One (1%) was definitely related to metyrapone (hypokalemia), 16 (18%) probably related, 20 (22%) possibly related, 35 (39%) unlikely to be related, and 18 (20%) unrelated to metyrapone. Dose was reduced in 5 patients (19%) due to an AE. Two discontinued metyrapone, one because of AKI, while the other withdrew from the study. Morning serum cortisol was not significantly changed between baseline [11.5 (IQR 9.2-14.8)], 3 months [12.0 (IQR 11.0-15.0)], and 6 months [9.7 (IQR 7.9-12.5)] (normal: 4.8-20 mcg/dL). No patient developed AI (morning serum cortisol <10 mcg/dL and ACTH >60 pg/ml), but plasma ACTH significantly increased from baseline to 3 months [8.0 (IQR 5.4-20.8) vs. 18.0 (IQR 14.0-28.0), P=0.021] (normal: 10-60 pg/ml). Between 3 and 6 months, no significant change occurred in ACTH. AddiQol survey scores did not change significantly between baseline, 3 and 6 months. Conclusion: Metyrapone therapy in patients with MACS demonstrated a favorable safety profile with no occurrence of AI. Further investigation into efficacy and MACS-associated outcomes is warranted. Presentation: Sunday, July 13, 2025

Abstract Objectives The impact of mild autonomous cortisol secretion (MACS) on cognition is incompletely characterized. We aimed to assess cognition in patients with MACS, identify factors associated with lower cognition, and determine the impact of adrenalectomy on cognition. Methods We conducted a cross-sectional study (4/2019 to 10/2022) and a longitudinal cohort study (10/2021 to 9/2023) of adults with MACS and referent subjects. Cognition was assessed with National Institute of Health Toolbox Cognition Battery and reported as standardized T scores (adjusted for age, sex, race/ethnicity, and education) for fluid, crystallized, and total composite cognition. Participants were assessed with urine steroid profiling (liquid chromatography-tandem mass spectrometry), frailty index, Beck’s Depression Inventory (BDI), and Short Form-36 (SF-36). Results A total of 84 patients (median age 57 years, 67% women) and 201 referent subjects (median age 63 years, 58% women) were included. Patients with MACS demonstrated lower mean (SD) total composite (50.9 [9.3] vs 55.4 [8.9], P < .001) and fluid composite T score (49.3 [10.6] vs 55.2 [10.2], P < .001), but not crystallized composite T score (52.3 [8.4] vs 54.0 [8.4], P = .130) when compared with referent subjects. Multivariable analysis adjusted for age, sex, BDI, SF-36, frailty index, total glucocorticoids, and androgens demonstrated that MACS status was associated with lower cognition. When cognition was reassessed in 37 patients post-adrenalectomy and 31 referent subjects, adjusted group differences of cognition change were similar except for a higher comparative increase in attention and executive functioning in patients with MACS. Conclusion Patients with MACS demonstrate lower cognition than referent subjects. Adrenalectomy for MACS had a minor positive impact on cognition.

Abstract Disclosure: E.Y. Ferreira: None. J. Saini: None. J. Larson: None. E. Atkinson: None. C. Powell: None. S. Nevin: None. V. Fell: None. I. Bancos: Grant Recipient; Self; HRA Pharmaceuticals. Research Investigator; Self; HRA Pharmaceuticals. Context: Mild autonomous cortisol secretion (MACS) is the most prevalent hormonal abnormality demonstrated in 20-45% of patients with adrenal adenomas. MACS is associated with increased prevalence and incidence of cardiovascular morbidity, frailty, fragility fractures, psychiatric and sleep disorders, as well as increased mortality. Bilateral MACS due to bilateral adrenal adenomas or macronodular adrenal hyperplasia is seen in around 20% of patients with MACS. Management of patients with unilateral MACS who are not surgical candidates or do not desire adrenalectomy, and management of patients with bilateral MACS is challenging. Safe and effective medical therapy is urgently needed in these patients. Objective: 1) assess safety and tolerability of overnight metyrapone therapy in patients with MACS, 2) evaluate the impact of overnight metyrapone on steroid profiling and circadian cortisol secretion and 3) determine the efficacy of overnight metyrapone on metabolic and bone parameters, mood, sleep, cognition, quality of life, frailty and senescence biomarkers. Methods: This open-label, phase 2 interventional single-center study using overnight metyrapone opened for enrollment in December 2023 (NTC06106295) and plans to enroll 30 patients with MACS. Eligible participants include adults with adrenal adenoma or macronodular adrenal hyperplasia and MACS, and at least one comorbidity attributed to hypercortisolism. Metyrapone is administered overnight at 250 mg to 1000 mg. Duration of the study is 6 months (main study) and up to 42 months for extension study. Primary endpoint is incidence of treatment related adverse events. Key secondary endpoints include: glucocorticoid/androgen ratio, morning/evening cortisol curve, metabolic parameters (change in blood pressure, hyperglycemia, weight), frailty index and senescence biomarkers. Results: Between December 15th 2023 and April 6th, 7 patients with MACS (4, 57% women) enrolled at a median age of 62 years (IQR 56-68). Median BMI was 29 kg/m2(IQR 25-34). Post-dexamethasone cortisol was 3.1 mcg/dL (IQR 2.4-6.2), corticotropin (ACTH) was 7.3 pg/mL (IQR 5-20), and dehydroepiandrosterone-sulfate (DHEAS) was 73 mcg/dL (IQR 59-86). Median hypercortisolism clinical severity score was 9 (IQR 2-11) and biochemical severity score was 3.5 (IQR 2-5). Prevalence of hypertension (57%), dysglycemia (67%), dyslipidemia (86%), depression (57%), anxiety (43%), and bone disease (70%) was high. In 7 participants, median frailty index was 0.2 (IQR 0.2-0.4), and 3 (43%) were considered frail (frailty index >0.25). As of April 6th, 2024, no major treatment-related adverse events were reported, and no patient discontinued therapy. Conclusion: Results of this study will characterize safety and tolerability of overnight metyrapone in patients with MACS and evaluate the impact of overnight metyrapone on MACS-associated comorbidities. Presentation: 6/1/2024