Czerwiec, Frank S.

Abstract Disclosure: M. Fleseriu: None. C.P. Badiu: None. I. Bancos: None. E.B. Geer: None. M. Orbetzova: None. J.M. Silverstein: None. I. Uzunova: None. K.C. Yuen: None. T.K. Marmon: None. D.A. Katz: None. F.S. Czerwiec: None. Introduction: 11β-hydroxysteroid dehydrogenase type 1 (HSD-1) regulates exposures of intracellular receptors to active glucocorticoids. HSD-1 deficiency suppresses a Cushing syndrome (CS) phenotype despite presence of hypercortisolism.1-3 Treatment with clofutriben (C), a potent and specific inhibitor of HSD-1, might improve CS comorbidities by decreasing intracellular cortisol. Methods: Seventeen adults with CS (16 pituitary, 1 ectopic), and type 2 diabetes (T2D), impaired glucose tolerance (IGT), hypertension (HTN), hyperlipidemia, or osteopenia were randomized to a total of 12 weeks of oral C 6mg/d and 12 weeks of matching placebo (P) in 2 blinded sequences (PCCP, CCPP; “P” or “C” representing 6-week periods). Patients were offered open-label C treatment on completion. Primary endpoint was urinary ratio of cortisol and cortisone metabolites at Week 6 (hepatocellular HSD-1 activity biomarker). Key exploratory endpoints (and applicable population) at Week 6 were OGTT-AUCglucose decrease 25% (IGT/T2D), HbA1c decrease ≥ 0.5% (T2D), systolic blood pressure decrease ≥ 5mmHg or decreased treatment (HTN), and normalization of urinary free cortisol (baseline >1.5xULN). Results: Mean baseline HSD-1 ratio was 1.95 +/- 0.171. At Week 6, mean ratio was 0.21 +/- 0.091 with C and 2.01 +/- 0.263 with P. More patients responded at Week 6 to C on OGTT-AUCglucose (4/8 v 0/5), HbA1c (4/5 v 0/4), systolic blood pressure (5/7 v 2/4), and urinary free cortisol (3/8 v 0/6). Concomitant medications for T2D were reduced in 4 C-treated but increased in 2 P-treated patients. For HTN there were also 4 reductions for C-treated and 1 increase for P-treated patients. One patient succumbed to ectopic Cushing’s due to cervical carcinoma after discontinuing the trial. Four patients discontinued for reasons other than an adverse event (AE). One serious AE of vomiting (possible glucocorticoid withdrawal syndrome per investigator) led to temporary drug interruption. Common AEs (≥ 3 patients) included Arthralgia, Fatigue, Headache, and Nausea, but only Headache was more common in C during the P-controlled period. There was no evidence of clinical or biochemical (defined by low morning plasma cortisol) adrenal insufficiency. All 13 patients who completed elected to enter the open-label extension (current treatment duration 3-15 months). Conclusions: Clofutriben decreased hepatic HSD-1 activity adequately to confer clinical benefit while maintaining safety and overall tolerability. These limited data support clofutriben’s potential for clinical improvement without adrenal insufficiency. References: 1Tomlinson JW 2002; 2Arai H 2008; 3Weber RJ 2024 Presentation: Sunday, July 13, 2025

Background and objectives In the 3-year Tolvaptan Efficacy and Safety in Management of ADPKD and Its Outcomes (TEMPO) 3:4 and 1-year Replicating Evidence of Preserved Renal Function: an Investigation of Tolvaptan Safety and Efficacy in ADPKD (REPRISE) trials, tolvaptan slowed the decline of eGFR in patients with autosomal dominant polycystic kidney disease at early and later stages of CKD, respectively. Our objective was to ascertain whether the reduction associated with the administration of tolvaptan is sustained, cumulative, and likely to delay the need for kidney replacement therapy. Design, setting, participants, & measurements One hundred and twenty-eight patients with autosomal dominant polycystic kidney disease participated in clinical trials of tolvaptan at the Mayo Clinic. All had the opportunity to enroll into open-label extension studies. Twenty participated in short-term studies or received placebo only. The remaining 108 were analyzed for safety. Ninety seven patients treated with tolvaptan for ≥1 year (mean±SD, 4.6±2.8; range, 1.1–11.2) were analyzed for efficacy using three approaches: ( 1 ) comparison of eGFR slopes and outcome (33% reduction from baseline eGFR) to controls matched by sex, age, and baseline eGFR; ( 2 ) Stability of eGFR slopes with duration of follow-up; and ( 3 ) comparison of observed and predicted eGFRs at last follow-up. Results Patients treated with tolvaptan had lower eGFR slopes from baseline (mean±SD, −2.20±2.18 ml/min per 1.73 m 2 per year) and from month 1 (mean±SD, −1.97±2.44 ml/min per 1.73 m 2 per year) compared with controls (mean±SD, −3.50±2.09 ml/min per 1.73 m 2 per year; P <0.001), and lower risk of a 33% reduction in eGFR (risk ratio, 0.63; 95% confidence interval, 0.38 to 0.98 from baseline; risk ratio, 0.53; 95% confidence interval, 0.31 to 0.85 from month 1). Annualized eGFR slopes of patients treated with tolvaptan did not change during follow-up and differences between observed and predicted eGFRs at last follow-up increased with duration of treatment. Conclusions Follow-up for up to 11.2 years (average 4.6 years) showed a sustained reduction in the annual rate of eGFR decline in patients treated with tolvaptan compared with controls and an increasing separation of eGFR values over time between the two groups.

The vasopressin–cAMP–osmolality axis is abnormal in autosomal dominant polycystic kidney disease (ADPKD). In the Tolvaptan Efficacy and Safety in Management of Autosomal Dominant Polycystic Kidney Disease and Its Outcomes 3:4 Trial, a 3-year randomized, placebo-controlled trial in adults, the vasopressin V2 receptor antagonist tolvaptan slowed ADPKD progression in patients with preserved GFR. Here, we investigated the determinants of baseline urine osmolality (Uosm) and its value as a severity marker of ADPKD, the factors influencing the response to tolvaptan, and whether change in Uosm associated with key trial end points. At baseline, lower Uosm independently associated with female sex, presence of hypertension, lower eGFR, higher total kidney volume (TKV), and higher age. Tolvaptan consistently reduced Uosm by 200–300 mOsm/kg over 36 months. The Uosm response to tolvaptan depended on baseline eGFR and Uosm. Subjects with greater change in Uosm experienced a significant reduction in clinical progression events. Among subjects receiving tolvaptan, those with a greater suppression of Uosm had slower renal function decline. Assessment at follow-up, off medication, revealed a significant decrease in Uosm in both placebo and treated groups. Tolvaptan significantly increased plasma osmolality, which returned to baseline at follow-up. In conclusion, baseline Uosm in ADPKD reflects age, renal function, and TKV, and baseline Uosm, eGFR, and TKV influence the effect of tolvaptan on Uosm. The greatest renal benefit occurred in subjects achieving greater suppression of Uosm, that is, those with better eGFR at baseline. These results support the link between vasopressin V2 receptor signaling and ADPKD progression.

Abstract Background: Autosomal-dominant polycystic kidney disease (ADPKD) is characterized by multitudes of expanding renal cysts associated with mononuclear interstitial infiltrates. Monocyte chemotactic protein-1 is produced in the kidneys and excreted in the urine (uMCP1) of these patients in increased amounts. In the TEMPO 3:4 trial, tolvaptan slowed the rate of increase in total kidney volume (TKV) and the rate of decline in estimated glomerular filtration rate (eGFR). In a sub-analysis, we determined whether tolvaptan administration for up to 3 years changed the urinary excretion of MCP-1 referenced to creatinine in 869 treated subjects compared with 438 placebo subjects. Methods: Treatment group differences of uMCP1 at 0.75, 12, 24 and 36 months were evaluated by ANCOVA with factor of treatment and covariate baseline. Results: At baseline, mean uMCP1 was 429 ± 224 pg/mg in the tolvaptan and 434 ± 233 pg/mg in the placebo groups, ∼4-fold greater than normal. Log uMCP1 associated positively with log TKV (r = 0.2645, P &lt; 0.0001) and negatively with eGFR (r = −0.1555 P &lt; 0.0001) and fasting urine osmolality (r = −0.1933, P &lt; 0.0001). Tolvaptan reduced uMCP1 13.8 ± 4.4% (P &lt; 0.0001) below placebo-treated subjects at 24 months and 14.4 ± 3.7% (P &lt; 0.0001) at 36 months, and to the same extent in females and males. The effect of tolvaptan on uMCP1 excretion at 36 months extended across CKD Stage 1 (11.1 ± 6.4%, P = 0.0595), CKD 2 (13.9 ± 5.4%, P = 0.0050) and CKD 3 (21.4 ± 8.0%, P = 0.0020). Conclusion: Tolvaptan, administered for 3 years to patients with ADPKD, caused a sustained reduction in the urinary excretion of MCP-1 relative to placebo.