Selective Glucocorticoid Receptor Modulators Research Articles

The effect of AZD9567 vs. prednisolone on glycaemic control in patients with type 2 diabetes mellitus: Results from a phase 2a clinical trial.

Corticosteroids are the treatment of choice for many inflammatory diseases but often lead to adverse effects, including hyperglycaemia. This study investigated the mechanisms driving differential effects on glucose control for AZD9567, an oral nonsteroidal selective glucocorticoid receptor modulator vs. prednisolone in 46 patients with type 2 diabetes mellitus. In this randomized, double-blind, 2-way cross-over study (NCT04556760), participants received either AZD9567 72 mg and prednisolone 40 mg daily (cohort 1); AZD9567 40 mg and prednisolone 20 mg daily (cohort 2); or placebo and prednisolone 5mg daily (cohort 3). Treatment duration was 3days with a 3-week washout between treatment periods. Glycaemic control was assessed after a standardized meal and with continuous glucose monitoring. A significant difference between AZD9567 and prednisolone in favour of AZD9567 was observed for the change from baseline to Day 4 glucose excursions postmeal in cohort 1 (glucose area under the curve from 0 to 4h -4.54%; 95% confidence interval [CI]: -8.88, -0.01; P = .049), but not in cohort 2 (-5.77%; 95% CI: -20.92, 12.29; P = .435). In cohort 1, significant differences between AZD9567 and prednisolone were also seen for the change from baseline to day 4 in insulin and glucagon secretion postmeal (P < .001 and P = .005, respectively) and change from baseline to Day 4 in GLP-1 response (P = .022). Significant differences between AZD9567 and prednisolone for 24-h glucose control were observed for both cohort 1 (-1.507 mmol/L; 95% CI: -2.0820, -0.9314; P < .001) and cohort 2 (-1.110 mmol/L; 95% CI -1.7257, -0.4941; P < .001). AZD9567 significantly reduced treatment-induced hyperglycaemia compared with prednisolone.

Vamorolone: revolutionizing Duchenne muscular dystrophy treatment

Duchenne muscular dystrophy (DMD) is a severe inherited neuromuscular disorder characterized by a dystrophin gene mutation, leading to progressive muscle weakness and structural degradation. Current management strategies focus on multidisciplinary approaches to mitigate symptoms and enhance quality of life. Conventional glucocorticoids present challenges due to their complex nature and severe side effects. Vamorolone, a first-in-class dissociative steroidal drug recently Food and Drug Administration (FDA) - approved, distinguishes itself through enduring anti-inflammatory effects with reduced safety concerns. Pharmacologically, Vamorolone's mechanism of action, differentiating it from traditional corticosteroids, involves selective glucocorticoid receptor (GR) modulation and mineralocorticoid receptor (MR) antagonism, offering improved safety and tolerability. Notably, its unique Δ9,11 modification prevents adverse receptor interactions, demonstrating superior safety in inhibiting inflammation across various cell types. This article explores Vamorolone's pharmacokinetics, drug interactions, and adverse effects, underscoring its well-tolerated profile with reversible hypothalamic-pituitary-adrenal axis suppression as a notable concern. Comparative studies against prednisone reveal Vamorolone's efficacy in improving muscle strength with minimal side effects, validated through the pivotal Phase IIb VISION-DMD study. Ultimately, Vamorolone has attained a breakthrough status in DMD treatment. Its endorsement by the FDA underscores Vamorolone as a transformative linchpin, heralding a new era in revolutionizing DMD care.

Characterization of a new selective glucocorticoid receptor modulator with anorexigenic activity

Obesity, a worldwide epidemic, leads to various metabolic disorders threatening human health. In response to stress or fasting, glucocorticoid (GC) levels are elevated to promote food intake. This involves GC-induced expression of the orexigenic neuropeptides in agouti-related protein (AgRP) neurons of the hypothalamic arcuate nucleus (ARC) via the GC receptor (GR). Here, we report a selective GR modulator (SGRM) that suppresses GR-induced transcription of genes with non-classical glucocorticoid response elements (GREs) such as Agrp-GRE, but not with classical GREs, and via this way may serve as a novel anti-obesity agent. We have identified a novel SGRM, 2-O-trans-p-coumaroylalphitolic acid (Zj7), a triterpenoid extracted from the Ziziphus jujube plant, that selectively suppresses GR transcriptional activity in Agrp-GRE without affecting classical GREs. Zj7 reduces the expression of orexigenic genes in the ARC and exerts a significant anorexigenic effect with weight loss in both high fat diet-induced obese and genetically obese db/db mouse models. Transcriptome analysis showed that Zj7 represses the expression of a group of orexigenic genes including Agrp and Npy induced by the synthetic GR ligand dexamethasone (Dex) in the hypothalamus. Taken together, Zj7, as a selective GR modulator, showed beneficial metabolic activities, in part by suppressing GR activity in non-classical GREs in orexigenic genes. This study demonstrates that a potential anorexigenic molecule may allow GRE-specific inhibition of GR transcriptional activity, which is a promising approach for the treatment of metabolic disorders.

A phase I trial of enzalutamide plus selective glucocorticoid receptor modulator relacorilant in patients with metastatic castration resistant prostate cancer.

Majority of patients with metastatic prostate cancer who receive androgen deprivation therapy and androgen receptor (AR) signaling inhibitors progress. Activation of the glucocorticoid receptor (GR) is associated with ARSI-resistance. This single-arm phase I trial assessed safety and pharmacokinetic feasibility of combined AR antagonist (enzalutamide) and selective GR modulator (relacorilant) in metastatic castration-resistant prostate cancer (mCRPC) patients. This was a phase I trial (NCT03674814) of relacorilant and enzalutamide in refractory mCRPC patients enrolled using 6+3 design. Enzalutamide dose was kept constant at 120 mg/day with escalating doses of relacorilant based on safety and pharmacokinetic measures in cohorts of ≥ 6 patients. Primary objective was safety and establishment of pharmacologically active doses. Secondary objectives were related to antitumor activity. Thirty-five mCRPC patients were enrolled. Twenty-three were accrued across 3 dose cohorts in the dose escalation phase and twelve enrolled at the recommended phase 2 dose. The combination was generally well-tolerated and safe and achieved desirable enzalutamide pharmacokinetics. RP2D of 120 mg/day + 150 mg/day respectively was established. Median time on study was 2.2 months with 4 patients remaining on study for longer than 11 months. Four of twelve evaluable patients had a PSA partial response. This is the first prospective trial combining an AR antagonist and a non-steroidal selective GR modulator. The combination was safe and well tolerated with PSA response and prolonged disease control observed in a limited subset of patients. Further prospective trials are justified to evaluate efficacy and identify predictive biomarkers of response.

Selective Modulation of the Human Glucocorticoid Receptor Compromises GR Chromatin Occupancy and Recruitment of p300/CBP and the Mediator Complex

Exogenous glucocorticoids are frequently used to treat inflammatory disorders and as adjuncts for the treatment of solid cancers. However, their use is associated with severe side effects and therapy resistance. Novel glucocorticoid receptor (GR) ligands with a patient-validated reduced side effect profile have not yet reached the clinic. GR is a member of the nuclear receptor family of transcription factors and heavily relies on interactions with coregulator proteins for its transcriptional activity. To elucidate the role of the GR interactome in the differential transcriptional activity of GR following treatment with the selective GR agonist and modulator dagrocorat compared to classic (ant)agonists, we generated comprehensive interactome maps by high-confidence proximity proteomics in lung epithelial carcinoma cells. We found that dagrocorat and the antagonist RU486 both reduced GR interaction with CREB-binding protein/p300 and the mediator complex compared to the full GR agonist dexamethasone. Chromatin immunoprecipitation assays revealed that these changes in GR interactome were accompanied by reduced GR chromatin occupancy with dagrocorat and RU486. Our data offer new insights into the role of differential coregulator recruitment in shaping ligand-specific GR-mediated transcriptional responses.

Synephrine and Its Derivative Compound A: Common and Specific Biological Effects.

This review is focused on synephrine, the principal phytochemical found in bitter orange and other medicinal plants and widely used as a dietary supplement for weight loss/body fat reduction. We examine different aspects of synephrine biology, delving into its established and potential molecular targets, as well as its mechanisms of action. We present an overview of the origin, chemical composition, receptors, and pharmacological properties of synephrine, including its anti-inflammatory and anti-cancer activity in various in vitro and animal models. Additionally, we conduct a comparative analysis of the molecular targets and effects of synephrine with those of its metabolite, selective glucocorticoid receptor agonist (SEGRA) Compound A (CpdA), which shares a similar chemical structure with synephrine. SEGRAs, including CpdA, have been extensively studied as glucocorticoid receptor activators that have a better benefit/risk profile than glucocorticoids due to their reduced adverse effects. We discuss the potential of synephrine usage as a template for the synthesis of new generation of non-steroidal SEGRAs. The review also provides insights into the safe pharmacological profile of synephrine.

Glucocorticoid Receptor (GR) Activation Is Associated with Increased cAMP/PKA Signaling in Castration-Resistant Prostate Cancer.

In castration-resistant prostate cancer (CRPC), increased glucocorticoid receptor (GR) expression and ensuing transcriptional activity have been proposed as an oncogenic "bypass" mechanism in response to androgen receptor (AR) signaling inhibition (ARSi). Here, we report that GR transcriptional activity acquired following ARSi is associated with the upregulation of cyclic adenosine monophosphate (cAMP)-associated gene expression pathways in both model systems and metastatic prostate cancer patient samples. In the context of ARSi, the expression of GR-mediated genes encoding cAMP signaling pathway-associated proteins can be inhibited by treatment with selective GR modulators (SGRMs). For example, in the context of ARSi, we found that GR activation resulted in upregulation of protein kinase inhibitor beta (PKIB) mRNA and protein levels, leading to nuclear accumulation of the cAMP-dependent protein kinase A catalytic subunit (PKA-c). Increased PKA-c, in turn, is associated with increased cAMP response element-binding protein phosphorylation and activity. Furthermore, enzalutamide and SGRM combination therapy in mice bearing CRPC xenografts delayed CRPC progression compared with enzalutamide therapy alone, and reduced tumor PKIB mRNA expression. Supporting the clinical importance of GR/PKA signaling activation in CRPC, we found a significant enrichment of both cAMP pathway signaling-associated gene expression and high NR3C1 (GR) activity in patient-derived xenograft models and metastatic human CRPC samples. These findings suggest a novel mechanism linking CRPC-induced GR transcriptional activity with increased cAMP signaling in AR-antagonized CRPC. Furthermore, our findings suggest that GR-specific modulation in addition to AR antagonism may delay GR+ CRPC time to recurrence, at least in part, by inhibiting tumor cAMP/PKA pathways.

Relacorilant, a Selective Glucocorticoid Receptor Modulator in Development for the Treatment of Patients With Cushing Syndrome, Does Not Cause Prolongation of the Cardiac QT Interval

ObjectiveTo assess the effect of relacorilant, a selective glucocorticoid receptor modulator under investigation for the treatment of patients with endogenous hypercortisolism (Cushing syndrome [CS]), on the heart rate–corrected QT interval (QTc). MethodsThree clinical studies of relacorilant were included: (1) a first-in-human, randomized, placebo-controlled, ascending-dose (up to 500 mg of relacorilant) study in healthy volunteers; (2) a phase 1 placebo- and positive-controlled thorough QTc (TQT) study of 400 and 800 mg of relacorilant in healthy volunteers; and (3) a phase 2, open-label study of up to 400 mg of relacorilant administered daily for up to 16 weeks in patients with CS. Electrocardiogram recordings were taken, and QTc change from baseline (ΔQTc) was calculated. The association of plasma relacorilant concentration with the effect on QTc in healthy volunteers was assessed using linear mixed-effects modeling. ResultsAcross all studies, no notable changes in the electrocardiogram parameters were observed. At all time points and with all doses of relacorilant, including supratherapeutic doses, ΔQTc was small, generally negative, and, in the placebo-controlled studies, similar to placebo. In the TQT study, placebo-corrected ΔQTc with relacorilant was small and negative, whereas placebo-corrected ΔQTc with moxifloxacin positive control showed rapid QTc prolongation. These results constituted a negative TQT study. The model-estimated slopes of the concentration-QTc relationship were slightly negative, excluding an association of relacorilant with prolonged QTc. ConclusionAt all doses studied, relacorilant consistently demonstrated a lack of QTc prolongation in healthy volunteers and patients with CS, including in the TQT study. Ongoing phase 3 studies will help further establish the overall benefit-risk profile of relacorilant.

THU475 Ovarian Tumor-cell Glucocorticoid Receptor Activity Modulates Cytokine Secretion Promoting Recruitment And Activation of Immunosuppressive Cells Into The Tumor Microenvironment

Abstract Disclosure: M. Taya: None. E. LeBlanc: None. L. Bennett: None. S.D. Conzen: None. Elevated levels of immunosuppressive myeloid-derived suppressor cells (MDSCs) circulate in the peripheral blood or infiltrate both tumors and ascites in ovarian cancer patients, however the cause for this observed phenotype is unknown. MDSCs contribute to tumor immune tolerance primarily via inhibition of cytotoxic T-cells or by activation of immunosuppressive T-regulatory cells. We previously showed that high tumor cell glucocorticoid receptor (GR) expression is associated with a relatively poor prognosis in ovarian cancer patients. Additionally, using primary tumor data retrieved from the ovarian cancer TCGA dataset, we show high tumor GR expression is associated with significantly higher expression of Foxp3, a marker of immunosuppressive T-regulatory cells, as well as CD33, a marker of immunosuppressive myeloid cells, further suggesting an immunosuppressive phenotype in ovarian cancer patients. We thus hypothesize that tumor-intrinsic GR activation in ovarian cancer is associated with increased MDSC infiltration into the tumor microenvironment partly due to the modulation of tumor cell cytokine secretion. To determine whether tumor-cell GR activation modulates the cytokine secretome, we previously showed that GR activation in ovarian cancer cells upregulates secretion of immunomodulatory factors including G-CSF, TGFb and CXCL5. Moreover, co-treatment of cells with a selective GR modulator (SGRM) reverses this effect. Preliminary gene expression data indicate GR mediated cytokine secretion and signaling may involve post-transcriptional or post-translational mechanisms. Considering that elevated levels of these cytokines are necessary for the production and recruitment of MDSCs, these data highlight the relevance of this evident glucocorticoid receptor-cytokine circuit in ovarian cancer cells. Furthermore, we show that this tumor-cell cytokine secretome has the capacity to promote differentiation of MDSCs from precursor myeloid cells in healthy PBMCs. Importantly, measuring expression of activation markers such as Arginase-1 and NOS2 illustrated that these MDSCs are in their functional state. To our knowledge, this is the first evidence that a nuclear receptor in ovarian cancer tumor cells is actively driving MDSC differentiation. Finally, employing ovarian cancer xenograft models as well as a syngeneic ID8 tumor model, treatment with SGRMs demonstrated reduced levels of circulating MDSCs in the peripheral blood as well as tumor infiltrated MDSCs. Using neutralizing antibodies for cytokines, we will now identify key mechanisms, specifically, which targetable immunomodulatory factors are contributing to immune suppression. Based on the insight provided by these data, we propose to determine whether targeting ovarian tumor cell-intrinsic GR activation and resulting MDSC infiltration contributes to improved anti-tumor immune response. Presentation: Thursday, June 15, 2023

THU035 Impact Of Surgery Or Medical Treatment With The Selective Glucocorticoid Receptor Modulator Relacorilant On Hypercoagulopathy In Patients With Cushing Syndrome

Abstract Disclosure: C. Simeoli: None. N. Di Paola: None. A. Stigliano: None. P. Lardo: None. T. Kearney: Other; Self; Corcept Therapeutics. E. Mezosi: Grant Recipient; Self; Corcept Therapeutics. E. Ghigo: None. R. Giordano: None. C.N. Mariash: Grant Recipient; Self; Corcept Therapeutics. D. Donegan: Advisory Board Member; Self; Corcept Therapeutics. Other; Self; Corcept Therapeutics. R.A. Feelders: Consulting Fee; Self; Recordati. Grant Recipient; Self; Corcept Therapeutics. Speaker; Self; Recordati, HRA Pharma. A.L. Hand: Employee; Self; Corcept Therapeutics. A.G. Moraitis: Employee; Self; Corcept Therapeutics. R. Pivonello: Consulting Fee; Self; Corcept Therapeutics. Grant Recipient; Self; Corcept Therapeutics. In patients with Cushing syndrome (CS), hypercoagulability represents a significant concern, leading to an elevated risk for thrombotic events. Hypercoagulability persists for several months (mos) after curative surgery, and current CS treatment guidelines recommend anticoagulation therapy for up to 3 mos after surgery. In patients with Cushing disease, hemostatic parameters may even worsen after surgery, independent of surgical outcome, with improvements beginning about 3 mos after successful surgery (Casonato et al. Blood Coagul Fibrinolysis 1999). This transient worsening may be due to increased inflammation as cortisol levels, and hence cortisol’s anti-inflammatory effects, are reduced after successful surgery, leading to increased activity in the coagulation cascade, which normalizes over time. Here, we evaluate the impact of surgery or treatment with the selective glucocorticoid receptor modulator relacorilant (RELA) on the coagulation state in patients with CS, reporting findings from a retrospective, longitudinal, monocentric, surgical cohort study and an open-label phase 2 study of RELA (NCT02804750). In the surgical study, coagulation markers were assessed in 30 patients before curative surgery and in remission. In the RELA study, patients received either RELA 100-200 mg for 12 weeks or RELA 250-400 mg for 16 weeks; coagulation markers were assessed in 34 patients throughout the study. In the surgical study, baseline (BL) mean 24-h urinary free cortisol (UFC) was 615.6 mcg/day (by immunoassay; 2.1x upper limit of normal [ULN]); mean and median time to hemostasis assessment after remission were 6.2 and 6 mos, respectively. Significant mean changes from BL were observed in activated partial thromboplastin time (aPTT; +2.0 sec, P=0.031), factor VIII (fVIII; -24.2%, P=0.044), and von Willebrand factor (vWF; -20.6%, P=0.018), whereas platelet count was unchanged. In the RELA study, BL mean UFC was 211.9 mcg/day (by tandem mass spectrometry; 4.2x ULN). Similar to the surgical study, significant mean changes from BL to last observed visit were reported in aPTT (+1.5 sec, P=0.046), fVIII (-18.9%, P=0.022), and platelet count (-68.8*109/L, P&amp;lt;0.0001), while vWF was unchanged. Significant improvements in other coagulation factors, eg, fIX and fX, were seen in patients with abnormal values at BL. These studies showed that coagulation markers in patients with CS improve 6 mos after curative surgery, and that treatment with RELA may have similar effects after 3-4 mos. The previously observed transient increase in fVIII immediately after surgery was absent with RELA, where negative mean changes from BL were seen throughout the study. This is presumably due to the less abrupt reduction of cortisol activity with RELA compared to surgery. RELA’s effects on hypercoagulopathy support further investigation of preoperative use and in patients with CS who are not eligible for surgery. Presentation: Thursday, June 15, 2023

Withaferin A: A potential selective glucocorticoid receptor modulator with anti-inflammatory effect.

Glucocorticoids have been widely applied to various clinical treatment, however some serious side effects may occur during the treatment. It is widely known that glucocorticoids produce a marked effect through binding to glucocorticoid receptor (GR). As withaferin A can provide multiple health benefits, this work aims to confirm withaferin A as a potential selective GR modulator with anti-inflammatory effect. Fluorescence polarization assay confirmed that withaferin A could steadily bind to GR with an IC50 value of 203.80 ± 0.36 μM. Meanwhile, glucocorticoid receptor translocation of withaferin A was measured by nuclear fractionation assay. Dual luciferase reporter assay showed that withaferin A did not activate GR transcription. Furthermore, withaferin A decreased the GR-related protein expression with less side effects. The result of molecular docking showed that hydrogen-bonding and hydrophobic interactions contributed to the binding of withaferin A with GR. In addition, the GR-withaferin A complex maintained a stable binding throughout the dynamics simulation process. Enzyme-linked immunosorbent assay showed that withaferin A inhibited the production of cytokines, confirming its anti-inflammatory effect. These findings indicate that withaferin A is a potential selective GR modulator and this work may provide a research basis for developing dietary supplements and nutraceuticals against inflammation.

The glucocorticoid receptor modulator relacorilant reverses the immunosuppressive effects of cortisol

Cortisol, an endogenous glucocorticoid receptor (GR) agonist, controls a broad transcriptional program that affects T-cell activation, pro-inflammatory cytokine secretion, apoptosis, and immune-cell trafficking. The degree to which endogenous cortisol blunts the anti-tumor immune response checkpoint inhibitors stimulate had not been assessed. We addressed this question using relacorilant, a selective GR modulator (SGRM) that competitively antagonizes the effects of cortisol activity. GR expression in human tumor and immune cells positively correlated with PD-L1 expression and tumor infiltration of Th2 and Treg cells, and negatively correlated with Th1-cell infiltration. In vitro, cortisol inhibited, and relacorilant restored, T-cell activation and pro-inflammatory cytokine secretion in human peripheral blood mononuclear cells. In the ovalbumin-expressing EG7 and MC38 immune-competent tumor models, relacorilant significantly improved anti-PD-1 antibody efficacy and showed favorable effects on antigen-specific T-cells and systemic TNFα and IL-10. These data characterize the broad immunosuppressive effects of endogenous cortisol and highlight the potential of combining an SGRM with an immune checkpoint inhibitor.

Impact of Surgery or Medical Treatment with the Selective Glucocorticoid Receptor Modulator Relacorilant on Hypercoagulopathy in Patients with Cushing Syndrome

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Abstract #1403093: Absence of QT Prolongation Associated with Relacorilant, a Selective Glucocorticoid Receptor Modulator in Development for the Treatment of Cushing Syndrome

QT prolongation is a significant concern for patients with Cushing syndrome (CS). Approximately 26% of men with CS present with QT prolongation, and the risk of cardiac arrhythmic events correlates with the extent of QT prolongation. All currently approved CS medications are associated with QT prolongation, posing a significant risk for the management of CS. Here, we evaluate the impact relacorilant, an investigational selective glucocorticoid receptor modulator, on QT prolongation in healthy volunteers and patients with CS. In a 3-part, single-center, first-in-human study (NCT03508635, “phase 1 study”), 103 healthy volunteers received single or multiple ascending doses of relacorilant (up to 500 mg QD) for up to 14 days; 24 received placebo. In a randomized, partial double-blind, crossover thorough QT study (NCT04795479, “TQT study”), the effect of multiple therapeutic (400 mg QD, n=25) and supra-therapeutic (800 mg QD, n=28) doses of relacorilant on cardiac repolarization was studied in healthy volunteers. A single dose of moxifloxacin (400 mg, n=28) was used as a positive control; 29 participants received placebo. In a single-arm, open-label phase 2 study (NCT02804750, “CS study”), 17 patients with CS received low-dose relacorilant (100–200 mg QD) for 12 weeks and 18 patients received high-dose relacorilant (250–400 mg QD) for 16 weeks. In all studies, ECG data were collected, and the heart rate-corrected QT interval using Fridericia’s formula (QTcF) was assessed. In the phase 1 study, relacorilant up to 500 mg daily did not adversely affect ECG parameters. An effect on placebo-corrected change from baseline QTcF (ΔΔQTcF) above 10 msec was excluded. In the TQT study, moxifloxacin control showed the expected QT prolongation, confirming assay sensitivity. Relacorilant had no adverse effects on ECG parameters and showed effects similar to placebo. Based on concentration-QTc analysis, an effect on ΔΔQTcF exceeding 10 msec was excluded within the full observed range of relacorilant plasma concentrations. These results constitute a negative TQT study. The CS study confirmed that these favorable findings also apply to patients with CS: Throughout the CS study, no significant changes in median QTcF were observed in either dose group. There is an unmet need for medications to treat CS that do not cause QT prolongation and possibly fatal arrhythmias. Based on the TQT study and supported by additional data in healthy volunteers and patients with CS, relacorilant did not show an association with QT prolongation.

Glucocorticoid Receptor and Ovarian Cancer: From Biology to Therapeutic Intervention

Ovarian cancer (OC) is the leading cause of death from gynecological malignancies worldwide. Fortunately, recent advances in OC biology and the discovery of novel therapeutic targets have led to the development of novel therapeutic agents that may improve the outcome of OC patients. The glucocorticoid receptor (GR) is a ligand-dependent transcriptional factor known for its role in body stress reactions, energy homeostasis and immune regulation. Notably, evidence suggests that GR may play a relevant role in tumor progression and may affect treatment response. In cell culture models, administration of low levels of glucocorticoids (GCs) suppresses OC growth and metastasis. Conversely, high GR expression has been associated with poor prognostic features and long-term outcomes in patients with OC. Moreover, both preclinical and clinical data have shown that GR activation impairs the effectiveness of chemotherapy by inducing the apoptotic pathways and cell differentiation. In this narrative review, we summarize data related to the function and role of GR in OC. To this aim, we reorganized the controversial and fragmented data regarding GR activity in OC and herein describe its potential use as a prognostic and predictive biomarker. Moreover, we explored the interplay between GR and BRCA expression and reviewed the latest therapeutic strategies such as non-selective GR antagonists and selective GR modulators to enhance chemotherapy sensitivity, and to finally provide new treatment options in OC patients.

Abstract 654: Ovarian cancer-cell glucocorticoid receptor activity modulates cytokine secretion promoting infiltration of immunosuppressive cells into the tumor microenvironment

Abstract Elevated levels of immunosuppressive myeloid-derived suppressor cells (MDSCs) circulate in the peripheral blood or infiltrate the tumors as well as ascites in ovarian cancer patients, however the cause for this observed phenotype is unknown. MDSCs contribute to tumor immune tolerance primarily via inhibition of cytotoxic T-cells or by activation of immunosuppressive T-regulatory cells. We previously showed that high tumor cell glucocorticoid receptor (GR) expression is associated with a relatively poor prognosis in ovarian cancer patients. Additionally, using primary tumor data retrieved from the ovarian cancer TCGA dataset, we show high tumor GR expression is associated with significantly higher expression of Foxp3, a marker of immunosuppressive T-regulatory cells, as well as CD33, a marker of immunosuppressive myeloid cells, further suggesting an immunosuppressive phenotype in ovarian cancer patients. We thus hypothesize that tumor-intrinsic GR activation in ovarian cancer is associated with increased MDSC infiltration into the tumor microenvironment in part via modulating tumor cell cytokine secretion. To determine whether tumor-cell GR activation modulates the cytokine secretome, we previously showed that GR activation in ovarian cancer cells upregulated secretion of immunomodulatory factors including G-CSF, TGFb and CXCL5. Moreover, co-treatment of cells with a selective GR modulator (SGRM), reverses this secretome effect. Considering that elevated levels of these cytokines are necessary for the production and recruitment of MDSCs, these data highlight the relevance of this evident glucocorticoid receptor-cytokine circuit in ovarian cancer tumor cells. Furthermore, we show that this tumor-cell cytokine secretome has the capacity to promote differentiation of MDSCs from precursor myeloid cells in healthy PBMCs. Importantly, measuring expression of activation markers such as Arginase-1 and NOS2 illustrated that these MDSCs are in their functional state. To our knowledge this is the first evidence that a nuclear receptor in ovarian cancer tumor cells is actively driving MDSC differentiation. Finally, employing ovarian cancer xenograft models as well as a syngeneic ID8 tumor model, treatment with SGRMs demonstrated reduced levels of circulating MDSCs in the peripheral blood as well as tumor infiltrated MDSCs. Using neutralizing antibodies for cytokines, we will now identify key mechanisms, specifically, identify which targetable immunomodulatory factors are contributing to immune suppression. Based on the insight provided by these data, we propose to determine whether targeting ovarian tumor cell-intrinsic GR activation and resulting MDSC infiltration contributes to improved anti-tumor immune response. Citation Format: Manisha Taya, Eleanore LeBlanc, Lynda Bennett, Suzanne D. Conzen. Ovarian cancer-cell glucocorticoid receptor activity modulates cytokine secretion promoting infiltration of immunosuppressive cells into the tumor microenvironment [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 654.

Abstract 3434: Selective glucocorticoid receptor modulation reveals a new role for CLEC10A in patients with solid tumors

Abstract Selective glucocorticoid receptor (GR) modulators (SGRMs) represent a clinically validated mechanism of enhancing chemosensitivity and ameliorating the sequelae of hypercortisolism. While GRs reportedly control the expression of up to 20% of the human genome, specific targets of systemic GR antagonism in humans have yet to be identified. To address this question, we established a robust NanoString assay to measure candidate GR target genes in human blood and assessed them before and after therapy with the oral SGRM relacorilant, which selectively antagonizes the GR. In a randomized, controlled phase 2 study in patients with recurrent, platinum-resistant ovarian cancer (NCT03776812), gene changes were assessed in 139 patients after treatment with relacorilant + nab-paclitaxel (NP) or NP alone. Using cross-validated random forest methods, a gene panel that accurately identified patients who had received relacorilant was established (ROC AUC 0.945 +/- 0.038). In 13 patients who crossed over from NP alone to relacorilant + NP, the genes in the panel were modified only after crossover (paired t-test P=0.0003), validating the gene panel’s ability to detect GR activity. The 4 most induced (LILRB4, FPR3, CLEC10A, CCR2) and 4 most suppressed (CDKN1C, TNFRSF17, BRIP1, PDK1) genes by relacorilant + NP vs. NP alone were selected and shown to be reliable indicators of GR activity across clinical studies in patients with pancreatic, prostate, and other solid tumors (NCT04329949, NCT03674814, NCT02762981), independent of concomitant medications or other confounders. CLEC10A (C-type lectin domain containing 10A) was identified as a particularly sensitive marker of GR activity as its expression was strongly suppressed by the GR agonist prednisone in healthy volunteers (paired t-test P&amp;lt;0.00010, NCT03335956) and strongly induced by relacorilant in patients with solid tumors (paired t-test P&amp;lt;0.00010). CLEC10A induction in blood by relacorilant was associated with longer overall survival in patients with ovarian cancer treated with relacorilant + NP (HR=0.39, Cox PH P=0.0135). High baseline tumor CLEC10A expression was also associated with longer overall survival in a large tumor ‘omics’ database (N=1656 ovarian tumors; HR 0.8, log-rank P=0.0008). CLEC10A and the genes correlated with its expression were found to be primarily expressed by a specific subset of dendritic cells, supporting previous reports that GR agonism can suppress dendritic cells. This analysis of CLEC10A and other identified GR target genes confirmed that systemic GR activity in patients with a range of solid tumors can be modulated pharmacologically, indicates that GR modulation may be associated with survival in patients with ovarian cancer, and provides new insights into the systemic functions of the GR in humans. Citation Format: Nicoletta Colombo, Toon Van Gorp, Ursula A. Matulonis, Ana Oaknin, Rachel N. Grisham, Diane Provencher, Gini F. Fleming, Alexander B. Olawaiye, Erkut H. Borazanci, Russell Z. Szmulewitz, Subhagya A. Wadekar, Grace Mann, Hazel J. Hunt, Andrew E. Greenstein, Domenica Lorusso. Selective glucocorticoid receptor modulation reveals a new role for CLEC10A in patients with solid tumors [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2023; Part 1 (Regular and Invited Abstracts); 2023 Apr 14-19; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2023;83(7_Suppl):Abstract nr 3434.

Abstract P2-20-01: Patient-derived triple-negative breast cancer organoids as a platform for glucocorticoid receptor- mediated mechanisms of immunotherapy response and resistance

Abstract Background: In early-stage triple-negative breast cancer (TNBC), high glucocorticoid receptor (GR) expression correlates with worse relapse-free survival across TNBC subtypes, induces oncogenic gene expression and tumor cell survival, and potentiates anti-inflammatory or an anti-immunogenic phenotype. Immune checkpoint therapy has increased pathologic complete response rates in the neoadjuvant setting, however response to immunotherapy remains modest overall and the explanatory mechanisms for this phenomenon are incompletely understood. We sought a three-dimensional model of the TNBC immune microenvironment using patient-derived organoids (PDOs) that capture tumor heterogeneity, partially recapitulates tumor microenvironment, and can be established for longer-term in vitro/in-vivo translational study after exposure to immunotherapy. We hypothesize that during chemoimmunotherapy treatment of early-stage triple-negative breast cancer, high glucocorticoid receptor activity mediates an immunosuppressive phenotype and glucocorticoid receptor modulation can restore anti-tumor immunity. Methods and Results: We are successfully growing 5 PDOs out of 8 surgically resectedion samples tumors from patients with early-stage triple-negative breast cancer treated with chemotherapy vs. chemoimmunotherapy as per KEYNOTE-522. Interrogation of complementary TNBC cell line data revealed that GR activation downregulates the expression of immune checkpoint genes (PD-L1, B7-H3, B7-H4), while GR knockdown or treatment with a selective GR modulator restores expression of these immune checkpoint genes. TNBC-intrinsic GR activation increases the proportion of regulatory T cells vs. CD8+ T cells. In a coculture system of TNBC spheroids and T cells, GR activation in TNBC results in decreased activated CD8+ CD137+ T cells and use of the selective GR modulator increases the proportion of activated CD8+ CD137+ T cells. Conclusions and Future Directions: In early-stage triple-negative breast cancer, GR activation downregulates expression of immune checkpoint genes and reduction of GR activity restores expression. In a coculture system that recapitulates T cell repertoire found in triple-negative breast cancer, tumor-intrinsic GR activation results in increased regulatory T cell population and reduction of GR activity increases activated CD8+ CD137+ T cells. Ongoing analyses of TNBC organoid-immune coculture systems modeling high GR states will be used to (i) define cooperativity amongst immune checkpoint proteins in costimulation vs. coinhibition of anti-tumor responses and (ii) define novel pairs of receptor-ligands amongst TNBC:CD8+ vs. TNBC:Treg vs. CD8+:Treg as discovery of potential new therapeutic targets. Citation Format: Christine Shiang, Candace Frerich, Ishrat Durdana, Cheryl Lewis, Lynda B. Bennett, Carlos Arteaga, Suzanne D. Conzen. Patient-derived triple-negative breast cancer organoids as a platform for glucocorticoid receptor- mediated mechanisms of immunotherapy response and resistance [abstract]. In: Proceedings of the 2022 San Antonio Breast Cancer Symposium; 2022 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2023;83(5 Suppl):Abstract nr P2-20-01.

Phase 1 efficacy and pharmacodynamic results of exicorilant + enzalutamide in patients with metastatic castration-resistant prostate cancer.

145 Background: Metastatic castration-resistant prostate cancer (mCRPC) remains an incurable disease with significant morbidity. Androgen receptor (AR) signaling is a key driver of tumor growth in mCRPC, and AR-targeted therapies are the mainstay for patients (pts) with locally advanced or metastatic disease. Enzalutamide (ENZA) is commonly used, but resistance typically develops within 1–2 years. The glucocorticoid receptor (GR) can substitute for the AR, providing a tumor escape pathway (Arora et al. Cell 2013). In the 22Rv1 CRPC xenograft model, the selective GR modulator exicorilant (EXI) combined with ENZA reduced tumor growth, supporting the hypothesis that dual antagonism of GR + AR may block this escape pathway. Safety and pharmacokinetics from the first study of EXI + ENZA in pts with mCRPC (NCT03437941) were previously presented (Linch et al. ESMO 2022). Here, we report efficacy and pharmacodynamic (PD) results from the same study. Methods: Segment 1 (Seg 1) of this phase 1 study evaluated open-label, fasting, BID dosing of EXI (140 or 180 mg) + ENZA 160 mg QD. Segment 2 (Seg 2) tested QD dosing of EXI with food in a double-blind design: All pts received EXI 240 mg + ENZA and were randomized 3:1 to EXI titration (to 280 mg followed by 320 mg) or to remain on EXI 240 mg + placebo. Efficacy assessments included radiographic response and changes in prostate-specific antigen (PSA) levels. PSA was collected prior to study entry and PSA doubling times were calculated before and during treatment. PD analyses included baseline (BL) tumor GR expression and modulation of GR target genes in whole blood. As not all pts enrolled in Seg 1 were ENZA naïve, efficacy data are reported for Seg 2 only. Data cutoff date: July 7, 2022. Results: 39 pts were enrolled (Seg 1: 14, irrespective of prior ENZA exposure; Seg 2: 25, on a stable ENZA dose with rising PSA, defined as a 25% increase over nadir and absolute value &gt;1 ng/mL). In Seg 2, there were no radiographic responses, 18 pts had a best overall response of stable disease per PCWG3, and 1 pt achieved a PSA response (≥50% PSA reduction from BL). BL tumor GR expression was detectable in all assessed tumors. PD analyses demonstrated EXI modulation of GR target genes, such as CDKN1C. Comparable PD effects were observed across EXI doses (240–320 mg QD). While BL 24-h urinary free cortisol (UFC) for most pts was within the normal range, improvements in PSA doubling times after treatment with EXI + ENZA were predominantly observed in pts with higher BL UFC ( P&lt;0.05). Conclusions: This study did not include an ENZA-alone arm and was thus not designed to assess the contribution of EXI to the efficacy of the EXI + ENZA combination. In heavily pretreated pts with prior ENZA exposure, 1 PSA response and no radiographic responses were observed. PD analysis confirmed systemic GR modulation. Instances of PSA doubling time improvements were observed in pts with relatively higher UFC. Clinical trial information: NCT03437941 .

Genetically engineered human pituitary corticotroph tumor organoids exhibit divergent responses to glucocorticoid receptor modulators

Cushing's disease (CD) is a serious endocrine disorder attributed to an adrenocorticotropic hormone (ACTH)-secreting pituitary neuroendocrine tumor (PitNET) that that subsequently leads to chronic hypercortisolemia. PitNET regression has been reported following treatment with the investigational selective glucocorticoid receptor (GR) modulator relacorilant, but the mechanisms behind that effect remain unknown. Human PitNET organoid models were generated from induced human pluripotent stem cells (iPSCs) or fresh tissue obtained from CD patient PitNETs (hPITOs). Genetically engineered iPSC derived organoids were used to model the development of corticotroph PitNETs expressing USP48 (iPSCUSP48) or USP8 (iPSCUSP8) somatic mutations. Organoids were treated with the GR antagonist mifepristone or the GR modulator relacorilant with or without somatostatin receptor (SSTR) agonists pasireotide or octreotide. In iPSCUSP48 and iPSCUSP8 cultures, mifepristone induced a predominant expression of SSTR2 with a concomitant increase in ACTH secretion and tumor cell proliferation. Relacorilant predominantly induced SSTR5 expression and tumor cell apoptosis with minimal ACTH induction. Hedgehog signaling mediated the induction of SSTR2 and SSTR5 in response to mifepristone and relacorilant. Relacorilant sensitized PitNET organoid responsiveness to pasireotide. Therefore, our study identified the potential therapeutic use of relacorilant in combination with somatostatin analogs and demonstrated the advantages of relacorilant over mifepristone, supporting its further development for use in the treatment of Cushing's disease patients.