Assessment of Safety, Tolerability, Pharmacokinetics, and Pharmacological Effect of Orally Administered CORT125134: An Adaptive, Double-Blind, Randomized, Placebo-Controlled Phase 1 Clinical Study

Relacorilant in recurrent ovarian cancer: clinical evidence and future perspectives

INTRODUCTION

Relacorilant (CORT125134, Corcept Therapeutics) is a selective glucocorticoid receptor modulator, which reverses the glucocorticoid-mediated anti-apoptotic effects and restores the taxane chemosensitivity in epithelial ovarian cancer cells. Given those preclinical findings, relacorilant is currently under investigation in clinical trials in combination with nab-paclitaxel for the platinum-resistant ovarian cancer setting.

AREAS COVERED

Already published preclinical and clinical evidence of relacorilant antitumor activity was analyzed and discussed. Ongoing clinical trials registered on clincaltrials.gov were also reported. The review aimed to summarize the status of relacorilant, the mechanism of action, the published and ongoing trials, and its safety and efficacy.

EXPERT OPINION

Relacorilant combined with nab-paclitaxel, may represent a promising strategy for the treatment of platinum-resistant ovarian cancer patients. After preliminary positive results in terms of clinical efficacy, a randomized phase III trial is ongoing to confirm the findings from the published phase II study.

Investigation of selective glucocorticoid receptor modulation in high-grade serous ovarian cancer PDX models

OBJECTIVE

In ovarian cancer (OvCa), tumor cell high glucocorticoid receptor (GR) has been associated with poor patient prognosis. In vitro, GR activation inhibits chemotherapy-induced OvCa cell death in association with transcriptional upregulation of genes encoding anti-apoptotic proteins. A recent randomized phase II study demonstrated improvement in progression-free survival (PFS) for heavily pre-treated OvCa patients randomized to receive therapy with a selective GR modulator (SGRM) plus chemotherapy compared to chemotherapy alone. We hypothesized that SGRM therapy would improve carboplatin response in OvCa patient-derived xenograft (PDX).

METHODS

Six high-grade serous (HGS) OvCa PDX models expressing GR mRNA (NR3C1) and protein were treated with chemotherapy +/- SGRM. Tumor size was measured longitudinally by peritoneal transcutaneous ultrasonography.

RESULTS

One of the 6 GR-positive PDX models showed a significant improvement in PFS with the addition of a SGRM. Interestingly, the single model with an improved PFS was least carboplatin sensitive. Possible explanations for the modest SGRM activity include the high carboplatin sensitivity of 5 of the PDX tumors and the potential that SGRMs activate the tumor invasive immune cells in patients (absent from immunocompromised mice). The level of tumor GR protein expression alone appears insufficient for predicting SGRM response.

CONCLUSION

The significant improvement in PFS shown in 1 of the 6 models after treatment with a SGRM plus chemotherapy underscores the need to determine predictive biomarkers for SGRM therapy in HGS OvCa and to better identify patient subgroups that are most likely to benefit from adding GR modulation to chemotherapy.

A Phase I Trial of Enzalutamide Plus Selective Glucocorticoid Receptor Modulator Relacorilant in Patients with Metastatic Castration-Resistant Prostate Cancer

PURPOSE

The majority of patients with metastatic prostate cancer who receive androgen-deprivation therapy and androgen receptor (AR) signaling inhibitors (ARSI) progress. Activation of the glucocorticoid receptor (GR) is associated with ARSI resistance. This single-arm phase I trial assessed safety and pharmacokinetic (PK) feasibility of a combined AR antagonist (enzalutamide) and selective GR modulator (relacorilant) in patients with metastatic castration-resistant prostate cancer (mCRPC).

PATIENTS AND METHODS

This was a phase I trial (NCT03674814) of relacorilant and enzalutamide in patients with refractory mCRPC enrolled using a 6+3 design. The enzalutamide dose was kept constant at 120 mg/d with escalating doses of relacorilant based on safety and PK measures in cohorts of ≥6 patients. The primary objective was safety and establishment of pharmacologically active doses. Secondary objectives were related to antitumor activity.

RESULTS

Thirty-five patients with mCRPC were enrolled. Twenty-three were accrued across three dose cohorts in the dose-escalation phase, and 12 enrolled at the recommended phase II dose. The combination was generally well tolerated, safe, and achieved desirable enzalutamide PK. RP2D of 120 + 150 mg/d, respectively, was established. Median time on study was 2.2 months with four patients remaining on study for longer than 11 months. Four of 12 evaluable patients had a prostate-specific antigen (PSA) partial response.

CONCLUSIONS

This is the first prospective trial combining an AR antagonist and a nonsteroidal 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.

Prolonged HPA axis dysregulation in postpartum depression associated with adverse early life experiences: A cross-species translational study

Childhood and adolescent stress increase the risk of postpartum depression (PPD), often providing an increased probability of treatment refractoriness. Nevertheless, the mechanisms linking childhood/adolescent stress to PPD remain unclear. Our study investigated the longitudinal effects of adolescent stress on the hypothalamic-pituitary-adrenal (HPA) axis and postpartum behaviors in mice and humans. Adolescent social isolation prolonged glucocorticoid elevation, leading to long-lasting postpartum behavioral changes in female mice. These changes were unresponsive to current PPD treatments but improved with post-delivery glucocorticoid receptor antagonist treatment. Childhood/adolescent stress significantly impacted HPA axis dysregulation and PPD in human females. Repurposing glucocorticoid receptor antagonists for some cases of treatment-resistant PPD may be considered.

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

OBJECTIVE

To 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).

METHODS

Three 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.

RESULTS

Across 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.

CONCLUSION

At 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.

Glucocorticoid Receptor Antagonism Improves Glucose Metabolism in a Mouse Model of Polycystic Ovary Syndrome

Context

Polycystic ovary syndrome (PCOS) is a complex metabolic disorder associated with obesity, insulin resistance, and dyslipidemia. Hyperandrogenism is a major characteristic of PCOS. Increased androgen exposure is believed to deregulate metabolic processes in various tissues as part of the PCOS pathogenesis, predominantly through the androgen receptor (AR). Notably, various metabolic features in PCOS are similar to those observed after excess glucocorticoid exposure.

Objective

We hypothesized that glucocorticoid receptor (GR) signaling is involved in the metabolic symptoms of PCOS.

Methods

In a PCOS model of chronic dihydrotestosterone (DHT) exposure in female mice, we investigated whether GR signaling machinery was (de)regulated, and if treatment with a selective GR antagonist alleviated the metabolic symptoms.

Results

We observed an upregulation of GR messenger RNA expression in the liver after DHT exposure. In white adipose tissues and liver we found that DHT upregulated Hsd11b1, which encodes for the enzyme that converts inactive into active glucocorticoids. We found that preventive but not therapeutic administration of a GR antagonist alleviated DHT-induced hyperglycemia and restored glucose tolerance. We did not observe strong effects of GR antagonism in DHT-exposed mice on other features like total fat mass and lipid accumulation in various tissues.

Conclusion

We conclude that GR activation may play a role in glucose metabolism in DHT-exposed mice.

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.

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 T_reg 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.

An evaluation of pharmacological options for Cushing's disease: what are the state-of-the-art options?

INTRODUCTION

Untreated Cushing's syndrome (CS) is associated with significant morbidity and mortality. Cortisol normalization is a key goal to treatment. Pituitary surgery remains the first-line approach for Cushing's disease, but sometimes it is impracticable, unsuccessful, or complicated by recurrence. Medical therapy has been historically considered a palliative. However, in the latest years, interest on this topic has grown due to both the availability of new drugs and the reevaluation of the old, commonly used drugs in clinical practice.

AREAS COVERED

In this article, we will discuss the current options and future directions of medical therapy for CS, aiming at fitting best patients' features. An extensive literature search regarding already approved and investigational principles was conducted (PubMed, ClinicalTrials.gov. Available drugs include inhibitors of ACTH secretion, steroidogenesis inhibitors, and glucocorticoid receptor antagonists; drugs acting at different levels can be also combined in uncontrolled patients.

EXPERT OPINION

Since there is still no standardized pharmacological approach and the superiority of one drug over another has not been established yet in the absence of comparative studies, each time clinicians' choices should be patient-tailored. Age, gender, tumor features, severity of hypercortisolism, comorbidities/complications, rapidity of action, side effects, drug-drug interactions, contraindications, availability, patients' preferences, and costs should be all considered.

New advances in endocrine hypertension: from genes to biomarkers

Hypertension (HT) is a major cardiovascular risk factor that affects 10% to 40% of the general population in an age-dependent manner. Detection of secondary forms of HT is particularly important because it allows the targeted management of the underlying disease. Among hypertensive patients, the prevalence of endocrine HT reaches up to 10%. Adrenal diseases are the most frequent cause of endocrine HT and are associated with excess production of mineralocorticoids (mainly primary aldosteronism), glucocorticoids (Cushing syndrome), and catecholamines (pheochromocytoma). In addition, a few rare diseases directly affecting the action of mineralocorticoids and glucocorticoids in the kidney also lead to endocrine HT. Over the past years, genomic and genetic studies have allowed improving our knowledge on the molecular mechanisms of endocrine HT. Those discoveries have opened new opportunities to transfer knowledge to clinical practice for better diagnosis and specific treatment of affected subjects. In this review, we describe the physiology of adrenal hormone biosynthesis and action, the clinical and biochemical characteristics of different forms of endocrine HT, and their underlying genetic defects. We discuss the impact of these discoveries on diagnosis and management of patients, as well as new perspectives related to the use of new biomarkers for improved patient care.

Peripheral glucocorticoid receptor antagonism by relacorilant with modest HPA axis disinhibition

Glucocorticoid stress hormones are produced in response to hypothalamic-pituitary-adrenal (HPA) axis activation. Glucocorticoids are essential for physiology and exert numerous actions via binding to the glucocorticoid receptor (GR). Relacorilant is a highly selective GR antagonist currently undergoing a phase 3 clinical evaluation for the treatment of endogenous Cushing's syndrome. It was found that increases in serum adrenocorticotropic hormone (ACTH) and cortisol concentrations after relacorilant treatment were substantially less than the increases typically observed with mifepristone, but it is unclear what underlies these differences. In this study, we set out to further preclinically characterize relacorilant in comparison to the classical but non-selective GR antagonist mifepristone. In human HEK-293 cells, relacorilant potently antagonized dexamethasone- and cortisol-induced GR signaling, and in human peripheral blood mononuclear cells, relacorilant largely prevented the anti-inflammatory effects of dexamethasone. In mice, relacorilant treatment prevented hyperinsulinemia and immunosuppression caused by increased corticosterone exposure. Relacorilant treatment reduced the expression of classical GR target genes in peripheral tissues but not in the brain. In mice, relacorilant induced a modest disinhibition of the HPA axis as compared to mifepristone. In line with this, in mouse pituitary cells, relacorilant was generally less potent than mifepristone in regulating Pomc mRNA and ACTH release. This contrast between relacorilant and mifepristone is possibly due to the distinct transcriptional coregulator recruitment by the GR. In conclusion, relacorilant is thus an efficacious peripheral GR antagonist in mice with only modest disinhibition of the HPA axis, and the distinct properties of relacorilant endorse the potential of selective GR antagonist treatment for endogenous Cushing's syndrome.

Glucocorticoid receptor blockers

Mifepristone is the only glucocorticoid receptor antagonist currently approved for the treatment of Cushing's syndrome. Although originally developed as an abortifacient due to its blockade of the progesterone receptor, a number of case reports documented its efficacy as a glucocorticoid receptor blocker going back to 1985. The SEISMIC trial, published in 2012, provided sufficient data on efficacy and adverse effects for regulatory approval. Mifepristone provides clear benefits on glycemia, blood pressure, muscle weakness, body weight and the other myriad clinical manifestations of Cushing's syndrome. However, because it blocks the glucocorticoid receptor, blood cortisol and ACTH levels actually rise, rather than fall; this complicates patient management. Doses are adjusted based on clinical manifestations rather than hormone levels. Adverse effects include adrenal insufficiency due to overdosage, hypokalemia, and menorrhagia. Treatment of severe adrenal insufficiency requires high doses of dexamethasone. Other glucocorticoid receptor blockers without effects on the progesterone receptor are being developed. Because mifepristone inhibits CYP3A and CYP2C8/2C9, drug-drug interactions can occur. These potential adverse effects can largely be avoided with careful attention to detail. My opinion is that its current place in therapy is in patients with severe disease and in those not responding to other treatments.

Overcoming Taxane Resistance: Preclinical and Phase 1 Studies of Relacorilant, a Selective Glucocorticoid Receptor Modulator, with Nab-Paclitaxel in Solid Tumors

PURPOSE

Chemotherapy resistance remains a major problem in many solid tumors, including breast, ovarian, and pancreatic cancer. Glucocorticoids are one potential driver of chemotherapy resistance as they can mediate tumor progression via induction of cell-survival pathways. We investigated whether combining the selective glucocorticoid receptor (GR) modulator relacorilant with taxanes can enhance antitumor activity.

PATIENTS AND METHODS

The effect of relacorilant on paclitaxel efficacy was assessed in OVCAR5 cells in vitro and in the MIA PaCa-2 xenograft. A phase 1 study of patients with advanced solid tumors was conducted to determine the recommended phase 2 dose of relacorilant + nab-paclitaxel.

RESULTS

In OVCAR5 cells, relacorilant reversed the deleterious effects of glucocorticoids on paclitaxel efficacy (P < 0.001). Compared with paclitaxel alone, relacorilant + paclitaxel reduced tumor growth and slowed time to progression in xenograft models (both P < 0.0001). In the heavily pretreated phase 1 population [median (range) of prior regimens: 3 (1-8), prior taxane in 75.3% (55/73)], 33% (19/57) of response-evaluable patients achieved durable disease control (≥16 weeks) with relacorilant + nab-paclitaxel and 28.6% (12/42) experienced longer duration of benefit than on prior taxane (up to 6.4×). The most common dose-limiting toxicity of the combination was neutropenia, which was manageable with prophylactic G-CSF. Clinical benefit with relacorilant + nab-paclitaxel was also associated with GR-regulated transcript-level changes in a panel of GR-controlled genes.

CONCLUSIONS

The observed preclinical, clinical, and GR-specific pharmacodynamic responses demonstrate that selective GR modulation with relacorilant combined with nab-paclitaxel may promote chemotherapy response and is tolerable. Further evaluation of this combination in tumor types responsive to taxanes is ongoing.

Long-term effects of glucocorticoid excess on the brain

The metabolic and cardiovascular clinical manifestations in patients with Cushing's syndrome (CS) are generally well known. However, recent studies have broadened the perspective of the effects of hypercortisolism, showing that both endogenous and exogenous glucocorticoid excess alter brain functioning on several time scales. Consequently, cognitive deficits and neuropsychological symptoms are highly prevalent during both active CS and CS in remission, as well as during glucocorticoid treatment. In this review, we discuss the effects of endogenous hypercortisolism and exogenously induced glucocorticoid excess on the brain, as well as the prevalence of cognitive and neuropsychological deficits and their course after biochemical remission. Furthermore, we propose possible mechanisms that may underly neuronal changes, based on experimental models and in vitro studies. Finally, we offer recommendations for future studies.

Brain mineralocorticoid and glucocorticoid receptor balance in neuroendocrine regulation and stress-related psychiatric etiopathologies

Cortisol and corticosterone (CORT) coordinate circadian events and manage the stress response by differential activation of two complementary brain receptor systems, i.e., the mineralocorticoid receptor (MR) and the glucocorticoid receptor (GR), which mediate rapid non-genomic and slow genomic actions. Several recent discoveries are highlighted from molecular fine-tuning of the MR/GR balance by FKBP5 to CORTs role in neural network regulation underlying stress adaptation in emotional, cognitive, and social domains of behavior. The data suggest that MR mediates CORT action on risk assessment, social interaction, and response selection, while GR activation promotes memory consolidation and behavioral adaptation; there are also sex differences in CORT action. New evidence suggests that targeting the MR/GR balance resets a dysregulated stress response system and promotes resilience.

Mineralocorticoid receptor and glucocorticoid receptor work alone and together in cell-type-specific manner: Implications for resilience prediction and targeted therapy

'You can't roll the clock back and reverse the effects of experiences' Bruce McEwen used to say when explaining how allostasis labels the adaptive process. Here we will for once roll the clock back to the times that the science of the glucocorticoid hormone was honored with a Nobel prize and highlight the discovery of their receptors in the hippocampus as inroad to its current status as master regulator in control of stress coping and adaptation. Glucocorticoids operate in concert with numerous neurotransmitters, neuropeptides, and other hormones with the aim to facilitate processing of information in the neurocircuitry of stress, from anticipation and perception of a novel experience to behavioral adaptation and memory storage. This action, exerted by the glucocorticoids, is guided by two complementary receptor systems, mineralocorticoid receptors (MR) and glucocorticoid receptors (GR), that need to be balanced for a healthy stress response pattern. Here we discuss the cellular, neuroendocrine, and behavioral studies underlying the MR:GR balance concept, highlight the relevance of hypothalamic-pituitary-adrenal (HPA) -axis patterns and note the limited understanding yet of sexual dimorphism in glucocorticoid actions. We conclude with the prospect that (i) genetically and epigenetically regulated receptor variants dictate cell-type-specific transcriptome signatures of stress-related neuropsychiatric symptoms and (ii) selective receptor modulators are becoming available for more targeted treatment. These two new developments may help to 'restart the clock' with the prospect to support resilience.

Individualized medical treatment options in Cushing disease

Cushing disease (CD) is caused by a pituitary tumor which oversecretes adrenocorticotropic hormone (ACTH). It is a serious endocrine disease associated with increased mortality and impaired quality of life. The management of CD remains challenging. Although transsphenoidal surgery is the treatment of choice in most cases, in approximately half of CD patients, second or third-line treatment options are needed. Currently, new medical therapies are available which target adrenal steroidogenesis, pituitary somatostatin and dopamine receptors, and glucocorticoid receptors. Selection of which medication to use should be individualized and is determined by many factors including severity of the disease, possible side effects, patients preferences and local availability. The aim of this article is to describe currently available medical therapy to help clinicians individualize the treatment options in the context of recently updated Pituitary Society recommendations.

Hidden hypercortisolism: a too frequently neglected clinical condition

PURPOSE

Classic Cushing's syndrome (CS) is a severe disease characterized by central obesity, hypertension, easy bruising, striae rubrae, buffalo hump, proximal myopathy and hypertricosis. However, several CS cases have also been reported with unusual or camouflaged manifestations. In recent years, several authors investigated the prevalence of "hidden hypercortisolism" (HidHyCo) among subjects affected with bone fragility, hypertension and type 2 diabetes mellitus (DM2). The prevalence of the HidHyCo is estimated to be much higher than that of classic CS. However, similarly to classic CS, HidHyCo is known to increase the risk of fractures, cardiovascular disease and mortality.

METHODS

We reviewed all published cases of unusual presentations of hypercortisolism and studies specifically assessing the HidHyCo prevalence in diabetic, osteoporotic and hypertensive patients.

RESULTS

We found 49 HidHyCo cases, in whom bone fragility, hypertension and diabetes were the presenting manifestations of an otherwise silent hypercortisolism. Amongst these cases, 34.7%, 32.7%, 6.1% and 19.0%, respectively, had bone fragility, hypertension, DM2 or hypertension plus DM2 as the sole clinical manifestations of HidHyCo. Overall, 25% of HidHyCo cases were of pituitary origin, and bone fragility was the very prevalent first manifestation among them. In population studies, it is possible to estimate that 1-4% of patients with apparent primary osteoporosis has a HidHyCo and the prevalence of this condition among diabetics ranges between 3.4 and 10%.

CONCLUSION

These data indicate that patients with resistant or suddenly worsening hypertension or DM2 or unexplainable bone fragility should be screened for HidHyCo using the most recently approved sensitive cut-offs.

Glucocorticoid receptor antagonism promotes apoptosis in solid tumor cells

Background: Resistance to antiproliferative chemotherapies remains a significant challenge in the care of patients with solid tumors. Glucocorticoids, including endogenous cortisol, have been shown to induce pro-survival pathways in epithelial tumor cells. While pro-apoptotic effects of glucocorticoid receptor (GR) antagonism have been demonstrated under select conditions, the breadth and nature of these effects have not been fully established.

Materials and Methods: To guide studies in cancer patients, relacorilant, an investigational selective GR modulator (SGRM) that antagonizes cortisol activity, was assessed in various tumor types, with multiple cytotoxic combination partners, and in the presence of physiological cortisol concentrations.

Results: In the MIA PaCa-2 cell line, paclitaxel-driven apoptosis was blunted by cortisol and restored by relacorilant. In the OVCAR5 cell line, relacorilant improved the efficacy of paclitaxel and the potency of platinum agents. A screen to identify optimal combination partners for relacorilant showed that microtubule-targeted agents consistently benefited from combination with relacorilant. These findings were confirmed in xenograft models, including MIA PaCa-2, HeLa, and a cholangiocarcinoma patient-derived xenograft. In vivo, tumor-cell apoptosis was increased when relacorilant was added to paclitaxel in multiple models.

Conclusions: These observations support recently reported findings of clinical benefit when relacorilant is added to paclitaxel-containing therapy in patients with ovarian and pancreatic cancers and provide a new rationale for combining relacorilant with additional cytotoxic agents.

Progesterone Dampens Immune Responses in In Vitro Activated CD4+ T Cells and Affects Genes Associated With Autoimmune Diseases That Improve During Pregnancy

The changes in progesterone (P4) levels during and after pregnancy coincide with the temporary improvement and worsening of several autoimmune diseases like multiple sclerosis (MS) and rheumatoid arthritis (RA). Most likely immune-endocrine interactions play a major role in these pregnancy-induced effects. In this study, we used next generation sequencing to investigate the direct effects of P4 on CD4⁺ T cell activation, key event in pregnancy and disease. We report profound dampening effects of P4 on T cell activation, altering the gene and protein expression profile and reversing many of the changes induced during the activation. The transcriptomic changes induced by P4 were significantly enriched for genes associated with diseases known to be modulated during pregnancy such as MS, RA and psoriasis. STAT1 and STAT3 were significantly downregulated by P4 and their downstream targets were significantly enriched among the disease-associated genes. Several of these genes included well-known and disease-relevant cytokines, such as IL-12β, CXCL10 and OSM, which were further validated also at the protein level using proximity extension assay. Our results extend the previous knowledge of P4 as an immune regulatory hormone and support its importance during pregnancy for regulating potentially detrimental immune responses towards the semi-allogenic fetus. Further, our results also point toward a potential role for P4 in the pregnancy-induced disease immunomodulation and highlight the need for further studies evaluating P4 as a future treatment option.

The development of novel glucocorticoid receptor antagonists: From rational chemical design to therapeutic efficacy in metabolic disease models

Glucocorticoids regulate numerous processes in human physiology, but deregulated or excessive glucocorticoid receptor (GR) signaling contributes to the development of various pathologies including metabolic syndrome. For this reason, GR antagonists have considerable therapeutic value. Yet, the only GR antagonist that is clinically approved to date - mifepristone - exhibits cross-reactivity with other nuclear steroid receptors like the progesterone receptor. In this study, we set out to identify novel selective GR antagonists by combining rational chemical design with an unbiased in vitro and in vivo screening approach. Using this pipeline, we were able to identify CORT125329 as the compound with the best overall profile from our octahydro series of novel GR antagonists, and demonstrated that CORT125329 does not exhibit cross-reactivity with the progesterone receptor. Further in vivo testing showed beneficial activities of CORT125329 in models for excessive corticosterone exposure and short- and long-term high-fat diet-induced metabolic complications. Upon CORT125329 treatment, most metabolic parameters that deteriorated upon high-fat diet feeding were similarly improved in male and female mice, confirming activity in both sexes. However, some sexually dimorphic effects were observed including male-specific antagonism of GR activity in brown adipose tissue and female-specific lipid lowering activities after short-term CORT125329 treatment. Remarkably, CORT125329 exhibits beneficial metabolic effects despite its lack of GR antagonism in white adipose tissue. Rather, we propose that CORT125329 treatment restores metabolic activity in brown adipose tissue by stimulating lipolysis, mitochondrial activity and thermogenic capacity. In summary, we have identified CORT125329 as a selective GR antagonist with strong beneficial activities in metabolic disease models, paving the way for further clinical investigation.

Osilodrostat for the treatment of Cushing's disease

INTRODUCTION

The treatment of Cushing's disease (CD) has been advanced well with the introduction of treatment options like transsphenoidal surgery, radiosurgery, bilateral adrenalectomy, and various classes of medication; however, many patients still fail to achieve disease remission. Osilodrostat, an orally bioavailable adrenal steroidogenesis inhibitor, was approved in the USA and EU in 2020 for the treatment of CD.

AREAS COVERED

This review provides an overview of Cushing's disease and the newly FDA approved 11β-hydroxylase inhibitor, osilodrostat, for CD with a focus on pharmacodynamics, pharmacokinetics, safety and efficacy data, and phase 2 and 3 clinical trials.

EXPERT OPINION

Osilodrostat has proven clinical efficacy and tolerability in phase 2 and 3 trials with CD patients who had an inadequate or reoccurring response to transsphenoidal surgery (TSS) and conventional first-line treatment. The phase 3 trial (LINC3) had 86% of the treatment group respond with normal urinary free cortisol (UFC) level compared to 29% in the placebo group (p < 0.001). Deemed as well-tolerated in all current pivotal trials, oral osilodrostat provides a noninvasive option for patients who cannot undergo surgery or patients who have reoccurring hypercortisolemia.

Glucocorticoid receptor modulators decrease alcohol self-administration in male rats

Alcohol use disorder (AUD) is associated with the dysregulation of brain stress and reward systems, including glucocorticoid receptors (GRs). The mixed glucocorticoid/progesterone receptor antagonist mifepristone and selective GR antagonist CORT113176 have been shown to selectively reduce alcohol consumption in alcohol-dependent rats. Mifepristone has also been shown to decrease alcohol consumption and craving for alcohol in humans with AUD. The present study tested the effects of the GR modulators CORT118335, CORT122928, CORT108297, and CORT125134 on alcohol self-administration in nondependent (air-exposed) and alcohol-dependent (alcohol vapor-exposed) adult male rats. Different GR modulators recruit different GR-associated transcriptional cofactors. Thus, we hypothesized that these GR modulators would vary in their effects on alcohol drinking. CORT118335, CORT122928, and CORT125134 significantly reduced alcohol self-administration in both alcohol-dependent and nondependent rats. CORT108297 had no effect on alcohol self-administration in either group. The present results support the potential of GR modulators for the development of treatments for AUD. Future studies that characterize genomic and nongenomic effects of these GR modulators will elucidate potential molecular mechanisms that underlie alcohol drinking in alcohol-dependent and nondependent states.

Relacorilant, a Selective Glucocorticoid Receptor Modulator, Induces Clinical Improvements in Patients With Cushing Syndrome: Results From A Prospective, Open-Label Phase 2 Study

INTRODUCTION/PURPOSE

Relacorilant is a selective glucocorticoid receptor modulator (SGRM) with no progesterone receptor activity. We evaluated the efficacy and safety of relacorilant in patients with endogenous Cushing syndrome (CS).

MATERIALS AND METHODS

A single-arm, open-label, phase 2, dose-finding study with 2 dose groups (NCT02804750, https://clinicaltrials.gov/ct2/show/NCT02804750) was conducted at 19 sites in the U.S. and Europe. Low-dose relacorilant (100-200 mg/d; n = 17) was administered for 12 weeks or high-dose relacorilant (250-400 mg/d; n = 18) for 16 weeks; doses were up-titrated by 50 mg every 4 weeks. Outcome measures included proportion of patients with clinically meaningful changes in hypertension and/or hyperglycemia from baseline to last observed visit. For patients with hypertension, clinical response was defined as a ≥5-mmHg decrease in mean systolic or diastolic blood pressure, measured by a standardized and validated 24-h ABPM. For patients with hyperglycemia, clinical response was defined ad-hoc as ≥0.5% decrease in HbA1c, normalization or ≥50-mg/dL decrease in 2-h plasma glucose value on oral glucose tolerance test, or decrease in daily insulin (≥25%) or sulfonylurea dose (≥50%).

RESULTS

35 adults with CS and hypertension and/or hyperglycemia (impaired glucose tolerance or type 2 diabetes mellitus) were enrolled, of which 34 (24 women/10 men) received treatment and had postbaseline data. In the low-dose group, 5/12 patients (41.7%) with hypertension and 2/13 patients (15.4%) with hyperglycemia achieved response. In the high-dose group, 7/11 patients (63.6%) with hypertension and 6/12 patients (50%) with hyperglycemia achieved response. Common (≥20%) adverse events included back pain, headache, peripheral edema, nausea, pain at extremities, diarrhea, and dizziness. No drug-induced vaginal bleeding or hypokalemia occurred.

CONCLUSIONS

The SGRM relacorilant provided clinical benefit to patients with CS without undesirable antiprogesterone effects or drug-induced hypokalemia.

Recurrence after pituitary surgery in adult Cushing's disease: a systematic review on diagnosis and treatment

PURPOSE

Recurrence after pituitary surgery in Cushing's disease (CD) is a common problem ranging from 5% (minimum) to 50% (maximum) after initially successful surgery, respectively. In this review, we give an overview of the current literature regarding prevalence, diagnosis, and therapeutic options of recurrent CD.

METHODS

We systematically screened the literature regarding recurrent and persistent Cushing's disease using the MESH term Cushing's disease and recurrence. Of 717 results in PubMed, all manuscripts in English and German published between 1980 and April 2020 were screened. Case reports, comments, publications focusing on pediatric CD or CD in veterinary disciplines or studies with very small sample size (patient number < 10) were excluded. Also, papers on CD in pregnancy were not included in this review.

RESULTS AND CONCLUSIONS

Because of the high incidence of recurrence in CD, annual clinical and biochemical follow-up is paramount. 50% of recurrences occur during the first 50 months after first surgery. In case of recurrence, treatment options include second surgery, pituitary radiation, targeted medical therapy to control hypercortisolism, and bilateral adrenalectomy. Success rates of all these treatment options vary between 25 (some of the medical therapy) and 100% (bilateral adrenalectomy). All treatment options have specific advantages, limitations, and side effects. Therefore, treatment decisions have to be individualized according to the specific needs of the patient.

Management of patients with persistent or recurrent Cushing's disease after initial pituitary surgery

INTRODUCTION

Treatment options for persistent and recurrent Cushing's disease (CD) include an individualized approach for repeat surgery, medical treatment, radiation therapy (RT), and bilateral adrenalectomy (BLA).

AREAS COVERED

In this expert opinion perspective, the authors review the latest treatment(s) for persistent/recurrent CD. A PubMed search was undertaken (English articles through May 2020) and relevant articles discussed. Repeat pituitary surgery should be considered in most patients with proven hypercortisolism; there is potential for cure with low risk of major complications. Medical therapy is valuable either alone, while awaiting the effects of RT, or in preparation for BLA. Medical therapy includes steroidogenesis inhibitors, agents that act at the pituitary or glucocorticoid receptor level, and novel agents in development. Radiation therapy has been used successfully to treat CD, but hypopituitarism risk and delayed efficacy (improved with radiosurgery) are major drawbacks. Laparoscopic BLA is safe and effective in patients with severe, difficult-to-manage hypercortisolism, but long-term follow-up is required as corticotroph tumor progression can develop.

EXPERT OPINION

Treatment of persistent/recurrent CD is challenging. Most patients require >1 therapy to achieve long-lasting remission. There is currently no ideal single treatment option that provides high and rapid efficacy, low adverse effects, and preserves normal pituitary-adrenal axis function.

Advances in the Medical Treatment of Cushing Disease

Medical therapy has an adjunctive role in management of Cushing disease. Medical therapy is recommended for patients who received pituitary radiotherapy and are awaiting its salutary effects. Medications are used preoperatively to stabilize the condition of seriously ill patients before surgery. Medical therapy is used to control hypercortisolism in patients with uncertain tumor location. Medical therapies available for management of patients with Cushing disease include steroidogenesis inhibitors, centrally acting agents, and glucocorticoid receptor antagonists. All agents require careful monitoring to optimize clinical effectiveness and manage adverse effects. Novel agents in development may expand the armamentarium for management of this condition.

What is the role of medical therapy in adrenal-dependent Cushing's syndrome?

Medical therapy to control hypercortisolism in adrenal Cushing's syndrome is currently not the first-line therapy. However, in many clinical scenarios like pre-surgical treatment, in patients who are not suitable candidates for surgery or in patients with bilateral hyperplasia, medical therapy can be important representing the only viable treatment option. Adrenal steroidogenesis inhibitors and glucocorticoid receptor blockers have been used for many years: metyrapone, ketoconazole and mifepristone are in current use and effective. Mitotane can be used as well but is considered second-line therapy because of its high toxicity. Etomidate has a special position as emergency medication in severe hypercortisolism. New drugs are tested in prospective trials (levoketoconazole, osilidrostat and relacorilant) and might become effective alternatives to common drugs. Oher drugs - adrenal steroidogenesis inhibitors as well as glucocorticoid receptor antagonists - are currently tested in vitro.

Psychosocial Stress, Glucocorticoid Signaling, and Prostate Cancer Health Disparities in African American Men

Recent advances in our understanding of racial disparities in prostate cancer (PCa) incidence and mortality that disproportionately affect African American (AA) men have provided important insights into the psychosocial, socioeconomic, environmental, and molecular contributors. There is, however, limited mechanistic knowledge of how the interplay between these determinants influences prostate tumor aggressiveness in AA men and other men of African ancestry. Growing evidence indicates that chronic psychosocial stress in AA populations leads to sustained glucocorticoid signaling through the glucocorticoid receptor (GR), with negative physiological and pathological consequences. Compelling evidence indicates that treatment of castration-resistant prostate cancer (CRPC) with anti-androgen therapy activates GR signaling. This enhanced GR signaling bypasses androgen receptor (AR) signaling and transcriptionally activates both AR-target genes and GR-target genes, resulting in increased prostate tumor resistance to anti-androgen therapy, chemotherapy, and radiotherapy. Given its enhanced signaling in AA men, GR-together with specific genetic drivers-may promote CRPC progression and exacerbate tumor aggressiveness in this population, potentially contributing to PCa mortality disparities. Ongoing and future CRPC clinical trials that combine standard of care therapies with GR modulators should assess racial differences in therapy response and clinical outcomes in order to improve PCa health disparities that continue to exist for AA men.

Medical Treatment of Cushing's Disease: An Overview of the Current and Recent Clinical Trials

Cushing's disease (CD) is a serious endocrine disorder characterized by chronic hypercortisolism, or Cushing's syndrome (CS), caused by a corticotroph pituitary tumor, which induces an excessive adrenocorticotropic hormone (ACTH) and consequently cortisol secretion. CD presents a severe clinical burden, with impairment of the quality of life and increase in mortality. Pituitary surgery represents the first-line therapy, but it is non-curative in one third of patients, requiring additional treatments. Among second-line treatments, medical therapy is gradually gaining importance, although the current medical treatments are unable to reach optimal efficacy and safety profile. Therefore, new drugs and new formulations of presently available drugs are currently under clinical investigation in international clinical trials, in order to assess their efficacy and safety in CD, or in the general population of CS. Among pituitary-directed agents, pasireotide, in the twice-daily subcutaneous formulation, has been demonstrated to be an effective treatment both in clinical trials and in real-world studies, and extension studies of the phase II and III clinical trials reported evidence of long-term efficacy with general good safety profile, although associated with frequent hyperglycemia, which requires monitoring of glucose metabolism. Moreover, the most recent once-monthly intramuscular formulation, pasireotide long-acting release (LAR), showed similar efficacy and safety, but associated with potential better compliance profile in CD. Roscovitine is an experimental drug currently under investigation. Among adrenal-directed agents, metyrapone is the only historical agent currently under investigation in a prospective, multicenter, international clinical trial, that would likely clarify its efficacy and safety in a large population of patients with CS. Osilodrostat, a novel agent with a mechanism of action similar to metyrapone, seems to offer a rapid, sustained, and effective disease control of CD, according to recently completed clinical trials, whereas levoketoconazole, a different chemical formulation of the historical agent ketoconazole, is still under investigation in clinical trials, with preliminary evidences showing an effective and safe control of CS. ATR-101 is an experimental drug currently under investigation. Among glucocorticoid receptor-directed drugs, mifepristone has been demonstrated to improve clinical syndrome and comorbidities, especially hypertension and impairment of glucose metabolism, but the occurrence of hypokalemia and in women uterine disorders, due to the concomitant action on progestin receptor, requires caution, whereas the preliminary evidence on relacorilant, characterized by high selectivity for glucocorticoid receptor, suggested good efficacy in the control of hypertension and impairment of glucose metabolism, as well as a good safety profile, in CS. Finally, a limited experience has demonstrated that combination therapy might be an interesting approach in the management of CD. The current review provides a summary of the available evidences from current and recent clinical trials on CD, with a specific focus on preliminary data.

Medical Management of Cushing's Syndrome: Current and Emerging Treatments

Endogenous Cushing's syndrome is a chronic disease associated with increased morbidity and mortality if not appropriately treated. Recurrence and/or persistence of hypercortisolemia after surgical treatment, especially for Cushing's disease, are high, and long-term medical treatment is used to decrease cortisol levels and risk of metabolic comorbidities. Medical treatment is also often required while waiting for radiation effects to take place. In some cases, severe or life-threatening hypercortisolism must be urgently and medically treated, via intravenous medications or with combination therapy, before patients can undergo surgery. In the last decade, medical treatment has progressed from a few steroidogenesis inhibitors to three novel drug groups: new inhibitors for steroidogenic enzymes with possibly fewer side effects, pituitary-directed drugs that aim to inhibit the pathophysiological pathways of Cushing's disease, and glucocorticoid receptor antagonists that block cortisol's action. Understanding the pathophysiology of Cushing's syndrome has also led to the identification of potential targets that may decrease adrenocorticotrophic hormone and/or cortisol excess, and/or decrease tumor cell proliferation, and induce senescence or apoptosis. We provide here a review of current and near-future medical options to treat Cushing's syndrome, and discuss updates on clinical trials and the efficacy and safety of novel or in-development drugs, as well as future potential targets.

Current management of Cushing's disease

Cushing's disease (CD) is caused by a pituitary tumour that secretes adrenocorticotropin (ACTH) autonomously, leading to excess cortisol secretion from the adrenal glands. The condition is associated with increased morbidity and mortality that can be mitigated by treatments that result in sustained endocrine remission. Transsphenoidal pituitary surgery (TSS) remains the mainstay of treatment for CD but requires considerable neurosurgical expertise and experience in order to optimize patient outcomes. Up to 90% of patients with microadenomas (tumour below 1 cm in largest diameter) and 65% of patients with macroadenomas (tumour at or above 1 cm in greatest diameter) achieve endocrine remission after TSS by an experienced surgeon. Patients who are not in remission postoperatively or those who relapse may benefit from undergoing a second pituitary operation. Alternatively, radiation therapy to the sella with interim medical therapy, or bilateral adrenalectomy, can be effective as definitive treatments of CD. Medical therapy is currently adjunctive in most patients with CD and is generally prescribed to patients who are about to receive radiation therapy and will be awaiting its salutary effects to occur. Available treatment options include steroidogenesis inhibitors, centrally acting agents and glucocorticoid receptor antagonists. Several novel agents are in clinical trials and may eventually constitute additional treatment options for this serious condition.

Neurovascular glucocorticoid receptors and glucocorticoids: implications in health, neurological disorders and drug therapy

Glucocorticoid receptors (GRs) are ubiquitous transcription factors widely studied for their role in controlling events related to inflammation, stress and homeostasis. Recently, GRs have reemerged as crucial targets of investigation in neurological disorders, with a focus on pharmacological strategies to direct complex mechanistic GR regulation and improve therapy. In the brain, GRs control functions necessary for neurovascular integrity, including responses to stress, neurological changes mediated by the hypothalamic-pituitary-adrenal axis and brain-specific responses to corticosteroids. Therefore, this review will examine GR regulation at the neurovascular interface in normal and pathological conditions, pharmacological GR modulation and glucocorticoid insensitivity in neurological disorders.

Advances in the medical treatment of Cushing's syndrome

Cushing's syndrome is associated with multisystem morbidity and, when suboptimally treated, increased mortality. Medical therapy is an option for patients if surgery is not successful and can be classified into pituitary-directed drugs, steroid synthesis inhibitors, and glucocorticoid receptor antagonists. In the last decade there have been new developments in each drug category. Targeting dopamine and somatostatin receptors on corticotroph adenomas with cabergoline or pasireotide, or both, controls cortisol production in up to 40% of patients. Potential new targets in corticotroph adenomas include the epidermal growth factor receptor, cyclin-dependent kinases, and heat shock protein 90. Osilodrostat and levoketoconazole are new inhibitors of steroidogenesis and are currently being evaluated in multicentre trials. CORT125134 is a new selective glucocorticoid receptor antagonist under investigation. We summarise the drug therapies for various forms of Cushing's syndrome and focus on emerging drugs and drug targets that have the potential for new and effective tailor-made pharmacotherapy for patients with Cushing's syndrome.

Glucocorticoid receptor in cervical cancer: an immunhistochemical analysis

PURPOSE

Cervical cancer is one of the most frequent cancers in women worldwide. In most of all cases, a persistent HPV infection is the leading cause. HPV-specific sequences are able to bind glucocorticoid receptor (GR). Dexamethasone can increase the activity of early promoters in HPV16 and HPV18 interfering in transcription control of viral oncogenes. The aim of our study was to evaluate glucocorticoid receptor as transcriptional factor in its active form in the nucleus of in cervical cancer cells and to correlate the results with clinical patient specific parameters.

METHODS

A total of 250 paraffin-embedded cervical cancer samples obtained from patients having undergone surgery for cervical cancer were used for the study. The expression of GR was immunhistochemical examined and evaluated by a semi-quantitative scoring. SPSS software was used for the statistical evaluation of staining results and survival analysis of patients with cervical cancer.

RESULTS

GR is frequently expressed in cervical carcinoma tissue in favor of squamous cell carcinoma (SCC). An enhanced expression is correlated with rather small clinical stages. The expression of the GR is correlated with better overall survival and progression-free survival.

CONCLUSIONS

The glucocorticoid receptor is frequently expressed in cervical carcinoma tissue in favor of squamous cell carcinoma. An enhanced expression is correlated with rather small clinical stages. The expression of the analyzed receptor is correlated with better overall survival. Further studies are needed to determine useful treatment targets for glucocorticoid receptor manipulation.

Immune System Dysregulation During Spaceflight: Potential Countermeasures for Deep Space Exploration Missions

Recent studies have established that dysregulation of the human immune system and the reactivation of latent herpesviruses persists for the duration of a 6-month orbital spaceflight. It appears certain aspects of adaptive immunity are dysregulated during flight, yet some aspects of innate immunity are heightened. Interaction between adaptive and innate immunity also seems to be altered. Some crews experience persistent hypersensitivity reactions during flight. This phenomenon may, in synergy with extended duration and galactic radiation exposure, increase specific crew clinical risks during deep space exploration missions. The clinical challenge is based upon both the frequency of these phenomena in multiple crewmembers during low earth orbit missions and the inability to predict which specific individual crewmembers will experience these changes. Thus, a general countermeasure approach that offers the broadest possible coverage is needed. The vehicles, architecture, and mission profiles to enable such voyages are now under development. These include deployment and use of a cis-Lunar station (mid 2020s) with possible Moon surface operations, to be followed by multiple Mars flyby missions, and eventual human Mars surface exploration. Current ISS studies will continue to characterize physiological dysregulation associated with prolonged orbital spaceflight. However, sufficient information exists to begin consideration of both the need for, and nature of, specific immune countermeasures to ensure astronaut health. This article will review relevant in-place operational countermeasures onboard ISS and discuss a myriad of potential immune countermeasures for exploration missions. Discussion points include nutritional supplementation and functional foods, exercise and immunity, pharmacological options, the relationship between bone and immune countermeasures, and vaccination to mitigate herpes (and possibly other) virus risks. As the immune system has sentinel connectivity within every other physiological system, translational effects must be considered for all potential immune countermeasures. Finally, we shall discuss immune countermeasures in the context of their individualized implementation or precision medicine, based on crewmember specific immunological biases.