Bancos, Irina

Abstract Disclosure: J. Saini: None. S. Singh: None. A.L. Ebbehøj: None. C.D. Zhang: None. R. Nathani: None. V. Fell: None. E. Atkinson: None. S. Achenbach: None. A. Rivard: None. R.J. Singh: None. S.K. Grebe: None. I. Bancos: None. Abstract Context: Mild autonomous cortisol secretion (MACS) is diagnosed based on post-dexamethasone cortisol>1.8 mcg/dL. Scarce evidence exists on steroid circadian secretion and steroid metabolome in MACS. Objective: To characterize 24-hour urine steroid metabolome in patients with MACS and determine circadian differences in urine steroid profiling and cortisol concentrations in patients with MACS versus referent subjects. Design: Cross-sectional study, 2018-2023. Setting: Referral center Participants: 72 patients with MACS and 72 age-, sex-, BMI-, and menopausal status-matched referent subjects. Measurements: Urine was collected over a 24-hour (h) period in separate day- and night-time collections. High-resolution mass spectrometry assay was used to measure 25 steroids. A subgroup of patients and referent subjects were admitted for every 2-hour serum measurement of free and total cortisol. Outcomes: Steroids, sums, and ratios Results: Patients with MACS had lower mcg/24h median androgens (2084 vs 3283, P<0.001), higher glucocorticoids (15754 vs 12936, P<0.001), and higher glucocorticoid/androgen ratio (8.7 vs 3.9, P<0.001). Steroid day/night ratios were lower in patients when compared to referent subjects, reflecting a higher relative nocturnal steroid production in MACS. In a subgroup of 12 patients with MACS and 10 referent subjects, the 24-hour area under the curves for total and free cortisol were similar. However, nocturnal mean total (5.3 vs 4.0 mcg/dL, P=0.056) and free (0.2 vs 0.1 mcg/dL, P=0.035) cortisol were higher in patients vs referent subjects. Conclusion: Patients with MACS demonstrate an abnormal urine steroid metabolome, with a high glucocorticoid to androgen ratio, and a higher nocturnal steroid production. Presentation: 6/3/2024

Abstract Disclosure: J. Saini: None. B. Salama: None. S.R. Chacko: None. K. Yu: None. I. Bancos: None. Objective: Measurement of baseline dehydroepiandrosterone sulfate (DHEAS) is suggested by the guidelines in support of diagnosing mild autonomous cortisol secretion (MACS). However, evidence on the diagnostic accuracy of DHEAS in MACS is difficult to interpret due to differences in the diagnostic cutoffs, small sample size, and heterogeneous reference standards. We aimed to conduct a systematic review and meta-analysis of published literature to assess the performance of DHEAS in diagnosing MACS, as defined in the 2023 guidelines. Methods: A comprehensive search was conducted using several databases from each database’s inception to January 8th, 2024. Databases include Ovid MEDLINE (R) and Epub Ahead of Print, In-Process & Other Non-Indexed Citations, and Daily, Ovid EMBASE, Ovid Cochrane Central Register of Controlled Trials, Ovid Cochrane Databases of Systematic Reviews, and Scopus. Only original studies of at least 20 participants were included. MACS was defined as post-dexamethasone cortisol >1.8 mcg/dL. QUADAS-2 was used to assess the risk of bias. Bivariate and random effects meta-analysis was used to generate pooled diagnostic accuracy estimates. Results: The initial search yielded 285 articles, and only 7 studies met the inclusion criteria. In 7 studies (1 from North America, 3 from Asia, and 3 from Europe), a total of 574 patients with MACS and 830 referent subjects (patients with adrenal tumors without MACS) were included. The mean age was specified only in 5 studies and was similar in patients with MACS (55.5 years) and referent group (53.3 years). Patients with MACS had a higher number of women (323/472, 68.4%) as compared to the referent group (352/658, 53.4%). DHEAS cutoffs studied included: lower cutoff of age-and sex-specific ranges (3 studies), 40 mcg/dL (3 studies), 60 mcg/dL (1 study), and 67.5 mcg/dL (1 study). With increasing DHEAS cutoff, sensitivity for MACS diagnosis increased, and specificity decreased. Most studies (4 studies) used the chemiluminescent immunoassay to measure DHEAS. A meta-analysis of studies using DHEAS cut-off between 40-70 mcg/dL was performed, with a pooled sensitivity of 68% (95% CI: 51-81) and a pooled specificity of 85% (78-89). The positive likelihood ratio was 4 (95% CI: 3-6; I2=36.94, P=0.175) and the negative likelihood ratio was 0.4 (0.3-0.6; I2=49.97, P=0.092). Most studies were at a high risk of bias for selection of patients, index, or reference standard. Conclusion: Based on limited heterogeneous evidence, measurement of DHEAS provides additional value in diagnosing MACS. Further larger diagnostic accuracy studies should explore various DHEAS cutoffs and consider assay variability. Presentation: 6/3/2024

Abstract Disclosure: J. Saini: None. V. Fell: None. B. Atkinson: None. S. Achenbach: None. I. Bancos: None. Background: Patients with mild autonomous cortisol secretion (MACS) have a higher prevalence of frailty and reduced muscle strength as compared to patients with nonfunctioning adrenal adenomas or subjects without adrenal disorders. Objective: To determine the impact of adrenalectomy on frailty and parameters of functional strength in patients with MACS. Methods: We conducted a single-center prospective longitudinal study of adults with MACS scheduled for adrenalectomy and referent subjects evaluated between 2018 and 2023. MACS was defined as serum cortisol>1.8 mcg/dL after 1 mg dexamethasone suppression test in patients with adrenal adenomas and no features of overt hypercortisolism. Referent subjects were included if they had abdominal imaging and had no adrenal disorders. Patients and referent subjects had a baseline and a follow-up evaluation at least 10 months later. Differences were assessed using paired t-tests for (1) Frailty Index (FI)--calculated using a questionnaire containing 47 variables on comorbidities, symptoms, and daily living activities (frailty defined as FI>0.25) (2) physical function assessed using handgrip strength (Jamar Plus digital hand dynamometer), timed up-and-go test (time taken to rise from a chair, walk to and from 3 m, and sit down), gait speed, 6-minute walk test, and (3) Advanced Glycation End (AGE) Product (using AGE reader). Results: We evaluated 41 patients before and after adrenalectomy, and 31 referent subjects at baseline and follow-up visit, at a similar interval (median 1.6, IQR 1.2-2.0 vs 1.5 years, IQR 1.0-2.2, P=0.759). While sex distributions were no different between the 2 groups (women, 66% vs 84%, P=0.086), patients with MACS were older than the referent group (median age 57.3, IQR 48.8-66.9 vs 49.0, IQR 41.7-57.9 years, P=0.005). Post-adrenalectomy, FI decreased by a mean of 0.057 (SD 0.08), P<0.001 in patients, and remained unchanged in the referent group. AGE decreased in patients by 0.148 (SD 0.45), P=0.04 but not in referent subjects (-0.047, SD 0.242, P=0.5). Patients demonstrated no improvement in parameters of muscle strength: gait speed (mean change 0.305 m/s, P=0.453), 6-minute walk test (mean change 16.4 meters, P=0.201), dominant (mean Z score change -0.055, P=0.72) and nondominant (mean Z score change -0.199, P=0.192) hand grip muscle strength. At follow-up, both patients (mean change 1.897 seconds, P<0.001) and referent subjects (mean change=1.475 seconds, P<0.001) demonstrated a deterioration on the timed up-and-go test. Conclusions: While no improvement was seen in the parameters of muscle strength, adrenalectomy improved the frailty index in patients with MACS. In addition, AGE, a biomarker associated with cardiovascular morbidity, decreased after adrenalectomy, suggesting a beneficial cardiovascular impact of MACS reversal. Presentation: 6/1/2024

Abstract Disclosure: I. Bancos: Advisory Board Member; Self; Adrenas, Diurnal, Neurocrine, Spruce, HRA Pharmaceuticals, Sparrow, Recordati Rare Diseases, Xeris, Novo Nordisk, AstraZeneca, Corcept. Consulting Fee; Self; Adrenas, Diurnal, Neurocrine, Spruce, HRA Pharmaceuticals, Sparrow, Recordati Rare Diseases, Xeris, Novo Nordisk, AstraZeneca, Corcept. Grant Recipient; Self; Recordati, HRA Pharmaceuticals. Other; Self; Adrenas, Diurnal, Neurocrine, Spruce, HRA Pharmaceuticals, Sparrow, Recordati Rare Diseases, Xeris, Novo Nordisk, AstraZeneca, Corcept. E.B. Geer: Advisory Board Member; Self; Recordati Rare Diseases. Consulting Fee; Self; Lundbeck, Crinetics, HRA Pharmaceuticals, Recordati Rare Diseases, Sparrow, Xeris Pharmaceuticals (Strongbridge). Grant Recipient; Self; Xeris Pharmaceuticals (Strongbridge), Corcept, Recordati Rare Diseases, Sparrow. F. Castinetti: Consulting Fee; Self; HRA Pharmaceuticals, Recordati. Grant Recipient; Self; HRA Pharmaceuticals, Recordati. R. Feelders: Advisory Board Member; Self; Recordati. Consulting Fee; Self; HRA Pharmaceuticals, Recordati. Grant Recipient; Self; Corcept Therapeutics. M. Fleseriu: Advisory Board Member; Self; Recordati Rare Diseases. Consulting Fee; Self; Recordati Rare Diseases, Sparrow, Xeris Pharmaceuticals (Strongbridge). Grant Recipient; Self; Recordati Rare Diseases, Sparrow, Xeris Pharmaceuticals (Strongbridge). R. Pivonello: Consulting Fee; Self; Corcept Therapeutics, Recordati, Crinetics Pharmaceuticals, H Lundbeck. Grant Recipient; Self; Recordati, Corcept Therapeutics, Xeris Pharmaceuticals (Strongbridge), Neurocrine Biosciences. M. Reincke: Advisory Board Member; Self; Recordati Rare Diseases. Consulting Fee; Self; Recordati Rare Diseases, HRA Pharmaceuticals, Lundbeck, Crinetics. Grant Recipient; Self; Recordati Rare Diseases, HRA Pharmaceuticals, Lundbeck, Crinetics. Speaker; Self; Recordati Rare Diseases, HRA Pharmaceuticals, Lundbeck, Crinetics. A. Tabarin: Advisory Board Member; Self; Recordati Rare Diseases. Consulting Fee; Self; H Lundbeck, Crinetics, HRA Pharmaceuticals, Recordati Rare Diseases. J. Le Mouhaër: Employee; Self; Recordati. J. Stermenska: Employee; Self; Recordati. M. Maldonado: Employee; Self; Recordati. B.M. Biller: Advisory Board Member; Self; Recordati Rare Diseases. Consulting Fee; Self; H Lundbeck, Recordati Rare Diseases, Sparrow, Xeris Pharmaceuticals (Strongbridge). Introduction: Osilodrostat, a potent oral 11β-hydroxylase inhibitor, provides control of cortisol production and improves outcomes in patients (pts), as shown by the clinical development program of Cushing’s disease (CD; Fleseriu M et al. Lancet Diabetes Endocrinol 2021;9:847-75) leading to EMA approval for Cushing’s syndrome (CS) and FDA approval for CD. The prospective LINC 6 study (NCT05382156) evaluates long-term safety and efficacy of osilodrostat in routine clinical practice over a 3-­year follow-up of CS pts. Here, we report 1-year interim data. Methods: Pts aged ≥18 years with endogenous CS are being enrolled in countries where osilodrostat is approved and available (including USA and Europe), irrespective of prior osilodrostat use. Treatment decisions and follow-up are at investigator discretion. The primary endpoint is incidence of osilodrostat-related adverse events (AEs) and serious AEs, focusing on AEs related to hypocortisolism, accumulation of adrenal hormone precursors, QT prolongation and pituitary tumor enlargement. Secondary endpoints include change in mean urinary free cortisol (mUFC), serum cortisol and late-night salivary cortisol (LNSC). Evaluation of biochemical parameters is recommended at baseline, months 1 and 3, and every 3 months thereafter, as available. AEs are recorded at baseline and each visit. Analyses are descriptive. We report change for pts with assessments at baseline and every 3 months. Results: Of 106 pts enrolled at the 1-year interim analysis, 94 were included in the safety population: CD, n=78; non-CD CS, n=16 (adrenal adenoma, n=3; adrenal hyperplasia, n=3; ectopic, n=9; other, n=1). Mean (SD) age was 53.2 years (12.7); 70.2% (n=66) were female. Median (min-max) osilodrostat exposure and dose were 5.5 months (0.1-13.9) and 5.0 mg/day (1.0-60.0). 29 pts reported 109 AEs; 12 pts reported 44 AEs that were considered treatment related. Overall, the most common (≥5%) AEs were asthenia and vomiting (both n=6/109; 5.5%); treatment-related AEs with highest frequency were vomiting and dizziness (both n=4/44; 9.1%). 7 AEs led to discontinuation in 4 pts; 5 AEs were considered osilodrostat related (nausea and vomiting in 1 pt; worsening hypertension, uncontrolled blood pressure and dizziness in another) and 2 were not (pituitary tumor surgery and right adrenalectomy). AEs related to hypocortisolism, accumulation of adrenal hormone precursors, QT prolongation and pituitary tumor enlargement occurred in 7 (7.4%), 4 (4.3%), 2 (2.1%) and 0 pts, respectively. At month 3, mUFC, serum cortisol and LNSC were normalized in 71.4% (n=10/14), 69.2% (n=18/26) and 50.0% (n=7/14) of pts. Conclusions: Results from this real-world clinical setting show that osilodrostat is generally well tolerated and provides early improvements in mUFC and LNSC in pts with endogenous CS, building on evidence from the previous randomized, controlled trials LINC 3 and LINC 4. Presentation: 6/3/2024

Abstract Disclosure: L. Rahimi: None. J. Saini: None. E. Atkinson: None. S. Achenbach: None. A. Kattah: None. I. Bancos: None. Introduction: Patients with mild autonomous cortisol secretion (MACS) have higher prevalence of cardiovascular comorbidities including chronic kidney disease. However, considering that patients with MACS may have relative skeletal muscle atrophy, it is unclear whether the creatine-based assessment of kidney function is accurate in this population. Objective: To characterize the differences in assessing estimated glomerular filtration rate using cystatin (eGFRcys) versus creatinine (eGFRcre) in patients with MACS versus referent subjects. Methods: Cross-sectional single-center study, 2019-2022. MACS was defined as serum cortisol concentration >1.8 mcg/dL after the 1 mg overnight dexamethasone suppression test (DST). For each patient, eGFRcre, eGFRcys and eGFRcre/eGFRcys ratio were measured and compared between the two groups. Body composition was measured by DXA scan. The Kruskal-Wallis test was used to compare measurements between groups. Result: A total of 37 patients with MACS (median age 59 years (interquartile range, IQR 47-67), 25 (68%) women) and 45 referent subjects (median age 57 years (IQR 51-66), 30 (67%) women) were included. The distribution of BMI, total body fat mass and total body lean mass were similar between the two groups. In the MACS cohort, the median cortisol following 1-mg DST was 3.0 ug/dL (IQR, 2.2-4.0). While assessment of kidney function with eGFRcre showed no differences between patients with MACS and referent subjects (median 85.1 vs 87.0 ml/min/1.73m2, P=0.431), kidney function using eGFRcys was lower in MACS (median 78.0 vs 89.3 ml/min/1.73m2 in referents, P<0.014), resulting also in a higher eGFRcre/eGFRcys ratio (median 1.07 vs 0.97 in MACS vs referents, P=0.053). After adjusting for age, sex, and BMI, a higher 1 mg DST cortisol level in the MACS cohort was associated with a higher eGFRcre/eGFRcys ratio (Spearman correlation coefficient of 0.35, P = 0.042). Lower eGFRcys was associated with higher fat mass (Spearman correlation of -0.26, P = 0.023), and a higher eGFRcre/eGFRcys ratio showed a trend towards lower lean mass (Spearman correlation of -0.20, P = 0.081). Conclusion: Creatinine-based eGFR assessment in patients with MACS underestimates the degree of kidney dysfunction, likely due to underlying skeletal muscle atrophy. eGFRcys is a more accurate indicator of kidney function in patients with hypercortisolism. Presentation: 6/1/2024

Abstract Disclosure: J. Saini: None. V. Fell: None. B. Atkinson: None. S. Achenbach: None. I. Bancos: None. Background: Patients with mild autonomous cortisol secretion (MACS) have an impaired quality of life and a higher prevalence of sleep and mood disturbances as compared to patients with nonfunctioning adrenal adenomas. The impact of adrenalectomy on quality of life, mood, and sleep is unclear. Objective: To determine the impact of adrenalectomy on quality of life, sleep, and mood in patients with MACS Methods: We conducted a single-center prospective longitudinal study of adults with MACS scheduled for adrenalectomy and referent subjects evaluated between 2018 and 2023. MACS was defined as serum cortisol>1.8 mcg/dL after 1 mg dexamethasone suppression test in patients with adrenal adenomas and no features of overt hypercortisolism. Referent subjects were included if they had abdominal imaging and had no adrenal disorders. Patients and referent subjects had a baseline and a follow-up evaluation at least 10 months later. Differences were assessed using paired t-tests for (1) Quality of life using Short Form-36 (SF 36) survey (Physical and Mental component summary score), sex and age-adjusted (2) Mood using Beck’s Depression Inventory (BDI) (3) Sleep using Pittsburgh Sleep Quality Index (PSQI). Results: We evaluated 41 patients before and after adrenalectomy, and 31 referent subjects at baseline and follow-up visit, at a similar interval (median 1.6, IQR 1.2-2.0 vs 1.5 years, IQR 1.0-2.2, P=0.759). While sex distribution was similar between the groups (66% vs 84% women, P=0.086), patients with MACS were older than the referent group (median age 57.3, IQR 48.8-66.9 vs 49.0, IQR 41.7-57.9 years, P=0.005). After adrenalectomy, patients improved their mood with a mean decrease of -4.71 (SD: 9.11), P=0.002 on the BDI questionnaire. Patients also demonstrated improvement in the SF-36 mental component score by a mean of 6.48 (SD: 10.97), P<0.001. While the overall SF36 physical component score did not improve after adrenalectomy (1.953 (SD: 11.02), P=0.269), one of the PCS components, role-physical limitation, increased by a mean of 6.25 (SD: 13.03). Patients reported better sleep with PSQI score decreasing by a mean of -2.59 (SD: 3.64), P<0.001. No differences in BDI, SF36, and PSQI were observed between baseline and follow-up in referent subjects. Conclusions: After adrenalectomy, patients with MACS showed an improvement in sleep, mood, and mental component of quality of life. Presentation: 6/3/2024

Abstract Disclosure: C.A. Villavicencio Torres: None. Y. Chai: None. S.K. Grebe: None. T.D. Maus: None. I. Bancos: None. Background: Mild autonomous cortisol secretion (MACS) is diagnosed based on abnormal post-dexamethasone cortisol >1.8 mcg/dL. Late-night salivary cortisol (SalF) measurements in MACS are usually within normal ranges, and as such are not recommended by the adrenal incidentaloma guidelines. Late-night salivary cortisone (SalE) measurement may have a higher accuracy than SalF in diagnosing MACS. Objectives: To determine associations between SalF and SalE and post-dexamethasone cortisol concentrations in patients with MACS. Methods: We conducted a single-center retrospective cohort study of data between 2020-2023 that included patients with MACS who had concomitant SalF and SalE measurements at the time of diagnosis. Electronic medical records were reviewed for clinical, imaging, biochemical characteristics, and outcome data. Results: In 45 patients with MACS (31, 69% women) evaluated at a median age of 62 years (IQR 54-70), median post-dexamethasone cortisol was 3 mcg/dL (IQR 2.5-5.7), median corticotropin (ACTH) was 11 pg/mL (IQR 5.2-30), and median dehydroepiandrosterone sulfate (DHEAS) was 47.5 mcg/dL (IQR 27.8-98.8). In 36 patients, 24h-urine cortisol was also available, with a median cortisol of 14 mcg/dL (IQR 11.3-18), normal ranges <45 mcg/24h. Median adrenal adenoma size was 2.2 cm (IQR 1.6-3.0), and median unenhanced HU was 10 (IQR -5 to 22).Median SalF was 52 ng/dL (IQR 23.9-97.5), and median SalE was 332 ng/dL (IQR 222.5-607.0), with a median SalE/SalF ratio of 6.6 (IQR 5.7-9.0). SalF was normal (<50 ng/dL) in 22 (49%) patients with MACS, without differences in the post-dexamethasone cortisol concentrations between those with normal and abnormal SalF (median of 3 mcg/dL vs 3 mcg/dL, P=0.94). SalF correlated with SalE (R2=0.83, P<0.0001). However, only SalE was associated with post-dexamethasone cortisol (R2=0.09, P=0.04). Conclusion: SalE is associated with post-dexamethasone cortisol in patients with MACS and, after an appropriate validation, may provide additional value in support of diagnosis of MACS. Presentation: 6/3/2024

Abstract Disclosure: D. Ferone: Consulting Fee; Self; Camurus AB, Ipsen, Novartis-AAA, Recordati. Grant Recipient; Self; Camurus AB, Ipsen, Novartis-AAA, Recordati. Research Investigator; Self; Camurus AB. J.L. Spencer-Segal: Advisory Board Member; Self; Camurus AB. Research Investigator; Self; Camurus AB. G. Fidan Yaylali: None. M. Doknic: Speaker; Self; Pfizer, Inc., Novo Nordisk, Merck, Sandoz. E. Isaeva: None. A. Dreval: None. A. Gilis-Januszewska: None. E. Gezer: None. I. Bancos: Advisory Board Member; Self; Diurnal, Spruce, Neurocrine, Adrenas, Sparrow, Corcept, HRA Pharmaceuticals, Recordati, Xeris, AstraZeneca, Novo Nordisk. Grant Recipient; Self; Recordati, HRA Pharmaceuticals. L. Katznelson: Advisory Board Member; Self; Camurus AB, Recordati. M. Harrie: Employee; Self; Camurus AB. Stock Owner; Self; Camurus AB. A. Svedberg: Employee; Self; Camurus AB. Stock Owner; Self; Camurus AB. A.M. Pedroncelli: Employee; Self; Camurus AB. Stock Owner; Self; Camurus AB. F. Tiberg: Employee; Self; Camurus AB. Stock Owner; Self; Camurus AB. Background: Acromegaly is a rare, serious disorder characterized by overproduction of growth hormone (GH) and insulin-like growth factor 1 (IGF-1). There is a need for new, convenient therapies that provide effective disease control. CAM2029 is a novel subcutaneous octreotide depot designed for convenient once-monthly self-administration (ready-to-use syringe or injection pen). In a 24-week, Phase 3 trial (ACROINNOVA 1), CAM2029 was superior to placebo at attaining IGF-1 response (≤upper limit of normal [ULN] at week 22/24: 72.2% vs 37.5%; P=0.0018) in patients with acromegaly previously controlled under standard of care (SoC; octreotide long-acting repeatable [LAR]/lanreotide Autogel). Here, we report interim data from another Phase 3 trial of CAM2029 (ACROINNOVA 2; NCT04125836), focusing on the “New to CAM2029” subgroup of patients whose acromegaly was either controlled or uncontrolled under SoC. Methods: This 52-week, Phase 3, open-label trial (with a 52-week extension) enrolled patients who had received CAM2029 or placebo in ACROINNOVA 1 (reported separately) and “New to CAM2029” patients who were adequately or inadequately controlled (IGF-1 ≤2x ULN) on a stable dose of octreotide LAR/lanreotide Autogel for ≥3 months (data reported here). In the main part of the trial, new patients received once-monthly CAM2029 20 mg for up to 52 weeks. The primary endpoint was adverse events (AEs). Secondary endpoints included (i) the proportion of patients with IGF-1 ≤1x ULN (weeks 50/52 mean), (ii) the change from baseline in IGF-1, and (iii) the combined IGF-1 and GH response. Baseline values reflected SoC treatment. Data cutoff: May 23, 2023. Results: Eighty-one new patients were enrolled (mean age 51.8 years; 59.3% female). No new or unexpected safety signals were observed. The most common treatment-emergent AEs were injection site erythema (n=22) or swelling (n=13), and headache (n=12). AEs were mostly mild (grade 1/2); there were no serious or Grade 3 treatment-related AEs attributed to CAM2029. IGF-I response increased from 14.8% at baseline SoC (12/81) to 33.3% (20/60 patients with available data) at weeks 50/52. The estimated increase in IGF-1 response (linear probability model) from baseline at week 52 was 21.9% (95% CI: 9.6, 34.1). Biochemical control for both IGF-1 and GH improved over time: 30.0% of patients (18/60) had a combined IGF-1 and GH response at the end of the main part of trial, vs 11.7% (7/60) at baseline. Conclusion: CAM2029 was well tolerated with a safety profile consistent with that of SoC. Biochemical control rates improved from SoC baseline over 52 weeks of CAM2029 treatment in the “New to CAM2029” patients. These findings reinforce the efficacy and safety of CAM2029 in patients with acromegaly, including patients with uncontrolled disease with current SoC treatment (octreotide LAR/lanreotide Autogel). Presentation: 6/1/2024

Abstract Disclosure: B. Bahrani Fard: None. N. Nikravangolsefid: None. J. Maroun: None. A. Cross: None. T. Foster: None. T. McKenzie: None. W. Young Jr: None. B.M. Dy: None. M. Lyden: None. I. Bancos: None. Background: Giant pheochromocytomas (PHEO), defined based on size > 10 cm, are rare. Data on clinical presentation, management, and prognosis of giant PHEOs are scarce. Objectives: to determine prevalence of giant PHEO and compare presentation, management, and outcomes of patients with giant vs non-giant PHEOs. Methods: We conducted a single-center retrospective cohort study of consecutive patients with giant PHEO and randomly chosen patients with non-giant PHEO (referents) at 6:1 ratio, evaluated between 2000-2023. All variables were extracted from the electronic medical record. Results: Of 828 patients with PHEO evaluated between 2000 and 2023, 31 (3.7%) had giant PHEO (median size 12 cm, IQR 10.0-13.5). In comparison to referents (n=186, median size 4 cm, IQR, 2.9-5.0), patients with giant PHEO were similar in age (median age 53 vs 55 years, P=.55), more frequently discovered based on symptoms (52% vs 32%, P=.04), and less likely to be bilateral (3% vs 12%, P=.31). Genetic testing was performed in 103 (48%) of patients, without group differences, however, patients with giant PHEO were less likely to have an associated germline mutation detected (7% vs 47%, P=.004). Patients with giant PHEO had more symptoms of catecholamine excess (median of 2 vs 1, P=.04) and presented with a higher prevalence of severe metanephrine excess >10 times above upper normal range (76% vs 30%, P<.0001). Adrenalectomy was performed in 94% of patients with giant PHEOs and in 100% referents, with higher rates of open adrenalectomy in giant PHEO (86% vs 14%, P<.0001). In addition to preoperative alpha-adrenergic blockade (89%), metyrosine was used in 14 (7%) patients, mostly in patients with giant PHEO (26% vs 3%, P<.0001). Patients with giant PHEO had a longer hospital length of stay (laparoscopic: median 5 vs 2 days, P<.0001; open: median 6 vs 5 days, P=.24), and a higher complication rate (31% vs 10%, P=.006).Median follow up was 3 years (IQR 1-8) years, similar in patients and referents. Metastases developed at a much higher rate in patients with giant PHEOs (45% vs 4% in referents, P<.0001). Disease specific mortality was 7% in patients with giant PHEOs and 0% in referents. Conclusion: Patients with giant PHEO were more symptomatic, had a higher degree of catecholamine excess, and a higher rate of perioperative complications. Almost half of patients with giant PHEO developed metastases, warranting a close follow-up. Presentation: 6/2/2024

Abstract Disclosure: J. Saini: None. R. Nathani: None. J. Larson: None. V. Fell: None. I. Bancos: None. Background: Surgical menopause due to bilateral salpingo-oophorectomy (BSO) at a younger age is associated with an increased risk of cardiovascular disease, cognitive decline, and increased mortality. Aging is associated with abnormalities in steroid metabolome, most notably an increased glucocorticoid to androgen ratio (“adrenal aging”). We hypothesized that in postmenopausal women of the same age, the duration of menopause is associated with adrenal aging. Objective: To determine the differences in the adrenal steroid metabolome of women with a history of BSO as compared to age-matched women following natural menopause. Methods: We conducted a single-center cross-sectional study in postmenopausal women with or without a history of BSO, between December 2020 to December 2022 Each participant collected 24-hour urine, which was analyzed for steroid profiling by liquid chromatography-tandem mass spectrometry (25 steroids). Exclusion criteria were inability to collect a 24h urine sample, exogenous glucocorticoid use, advanced malignancy, and chronic opioid use. Primary endpoints were glucocorticoid/androgen ratio, 11β-hydroxysteroid dehydrogenase type 2 activity (cortisol/cortisone, Tetrahydrocortisol (THF) + 5 α-tetrahydrocortisol (5 α-THF)/ Tetrahydrocortisone, THE) and 5 α-reductase type activity (Tetrahydrocortisol (THF)/5 α-tetrahydrocortisol (5 α-THF) and Etiocholanolone/Androsterone, Et/An). Results: A total of 245 women were enrolled: 124 women (median age of 66 years, IQR 63-72) with a history of BSO and 121 women (median age of 68 years, IQR 64-71) who underwent natural menopause (P=0.214). Median age at menopause was 44 years (IQR 41-46) in the BSO group, and 50 years (IQR 48-53) in the natural menopause group. History of hormone replacement therapy with estrogen was reported in 161 (66%) women, more frequently (92% vs 39%, P<0.001) and for a longer duration (median 12 years (IQR 6-16) vs 6 years (IQR 3-9), P<0.001) in in the BSO group, as compared to the natural menopause group. Although both groups had similar levels of urinary androgens (median 1387 vs 1686 mcg/24h, P=0.063) and total glucocorticoids (median 10877 vs 10277 mcg/24h, P=0.354), women with a history of BSO demonstrated a higher glucocorticoid/androgen ratio (median 7.9 (IQR 5.0-11.1) vs 6.7 (4.3-9.9), P=0.014), and a lower Et/An ratio (median 1.4 vs 1.6, P=0.045), but not THF/5aTHF ratio (median 1.7 vs 1.8, P=0.380) in comparison to women with natural menopause. No differences were found in other ratios. Conclusion: Women with a history of BSO demonstrated a higher glucocorticoid/androgen ratio in comparison to women undergoing natural menopause, suggestive of BSO-induced accelerated “adrenal aging”. Future studies need to examine associations between the abnormal steroid metabolome and increased cardiovascular morbidity, frailty, and mortality reported following BSO. Presentation: 6/3/2024