The low-dose dexamethasone suppression test: a reevaluation in patients with Cushing’s syndrome

J Clin Endocrinol Metab. 2004 Mar;89(3):1222-6.

Findling JW1, Raff H, Aron DC.

Abstract

Low-dose dexamethasone suppression testing has been recommended for biochemical screening when Cushing’s syndrome is suspected. The criterion for normal suppression of cortisol after dexamethasone is controversial.

To assess diagnostic utility (sensitivity), we report the results of low-dose dexamethasone suppression testing in 103 patients with spontaneous Cushing’s syndrome. There were 80 patients with Cushing’s disease (78%), 13 with the ectopic ACTH syndrome (13%), and 10 with cortisol-producing adrenocortical adenomas (10%). Fourteen (18%) of 80 patients with Cushing’s disease suppressed serum cortisol to less than 5 micro g/dl (<135 nmol/liter) after the overnight 1-mg test, whereas six patients (8%) actually showed suppression of serum cortisol to less than 2 micro g/dl (<54 nmol/liter). In addition, the 2-d, low-dose dexamethasone suppression test yielded false-negative results in 38% of patients when urine cortisol was used and 28% when urinary 17-hydroxycorticosteroids were used. Serum cortisol after the 1-mg test correlated with baseline urinary free cortisol (r = 0.705, P < 0.001), plasma ACTH level (r = 0.322, P = 0.001), and urinary free cortisol after the 2-d test (r = 0.709, P = 0.001).

This study provides evidence that low-dose dexamethasone may suppress either plasma cortisol or urinary steroids to levels previously thought to exclude Cushing’s syndrome and that these tests should not be used as the sole criterion to exclude the diagnosis of endogenous hypercortisolism.

PMID:
15001614
[PubMed – indexed for MEDLINE]

From http://www.ncbi.nlm.nih.gov/pubmed/15001614

First Patient Dosed in IST of CDK Inhibitor Seliciclib in Cushing’s Disease, a Serious Endocrine Disorder

Source:Cyclacel Pharmaceuticals, Inc.

BERKELEY HEIGHTS, N.J., July 2, 2015 (GLOBE NEWSWIRE) — Cyclacel Pharmaceuticals, Inc. (NASDAQ:CYCC) (NASDAQ:CYCCP) (Cyclacel or the Company), a biopharmaceutical company developing oral therapies that target the various phases of cell cycle control for the treatment of cancer and other serious disorders today announced that the first patient has been dosed in an investigator sponsored trial (IST) of the Company’s oral cyclin dependent kinase (CDK) inhibitor seliciclib in Cushing’s disease (CD)1. Clinicians at Cedars-Sinai, Los Angeles, were awarded a grant from The National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) to evaluate seliciclib, a CDK2/9 inhibitor currently in clinical development to treat certain cancers, as a potential therapy for CD.

“Cushing’s disease is a serious debilitating endocrine disorder with limited treatment options for patients,” said Shlomo Melmed, M.D., Director of the Burns and Allen Research Institute, Principal Investigator and Dean of the Medical Faculty at Cedars-Sinai, Los Angeles. “We believe that seliciclib is unique among clinical stage CDK inhibitors in its potential effectiveness to treat this disease. Its mechanism of action has a dual effect as it impacts tumor growth by decreasing the levels and activity of cyclin E, as well as inhibiting ACTH production. If our trial with seliciclib proves successful, it could lead to dramatically improved treatment outcomes for patients with Cushing’s disease.”

CD is an endocrine disorder caused by adrenocorticotropin (ACTH)-producing pituitary tumors, often leading to obesity, diabetes, hypertension, osteoporosis and increased risk of death if inadequately controlled. Cell cycle dysregulation is a common feature of pituitary tumors, including upregulation of cyclin E, specifically seen in tumors of the corticotroph lineage, such as in CD. Dr. Melmed and Dr. Ning-Ai Liu have previously published preclinical proof-of-concept data showing that seliciclib is uniquely effective amongst CDK inhibitors in resolving the disease, with dual effects on pituitary growth and ACTH production2.

The trial is a Phase 2 proof-of-concept, open-label, single arm study to assess the safety and efficacy of seliciclib in CD. Sixteen patients with de novo, persistent or recurrent CD will receive seliciclib for 4 weeks prior to standard-of-care treatment. The primary objective is to establish the efficacy of seliciclib on normalizing urinary free cortisol levels in patients with CD.

About Cushing’s disease

CD is a rare endocrine, orphan disorder with estimated US prevalence of approximately 20,000. It is the most common cause of endogenous hypercortisolism, which predisposes patients to central obesity, diabetes, hypertension, osteoporosis and substantially increases their risk of infection, thrombosis and psychiatric disorders. If inadequately controlled, CD is fatal with mortality rate four-fold-higher than that of age- and sex-matched controls and median survival of 4.6 years. The leading cause of death in CD is cardiovascular disease. CD remains an unmet medical need despite available therapies.

About seliciclib and its mechanism of action in Cushing’s disease

Seliciclib, an orally-available CDK2/9 inhibitor, has been evaluated to date in approximately 450 patients and is currently being explored in combination with Cyclacel’s orally-available sapacitabine in patients with solid tumors.

Seliciclib has been shown in preclinical models to be uniquely effective amongst other CDK inhibitors. Seliciclib was subsequently shown, in mouse corticotroph tumor cells in vitro, to cause cell cycle arrest, accompanied by decreases in cyclin E levels, increased p27Kip1, p57Kip2 and p21Cip1 expression, and reduced Thr821 phosphorylation of the retinoblastoma (Rb) protein. Rb is reportedly a site phosphorylated by CDK2. In addition, ACTH concentrations in cell supernatant were also decreased by seliciclib, suggesting a dual impact of the compound on corticotroph tumorigenesis. In vivo, oral administration of seliciclib led to a 50% reduction in tumor weight, and consistent with in vitro observations, reduced plasma ACTH levels, serum cortisol levels and tumor PCNA staining.

1. ClinicalTrials.gov (NCT02160730).

2. Liu, N-A., Jiang, H., Ben-Shlomo, A., Wawrowsky, K. Fan, X-M., Lin, S. and Melmed, S. (2011) Targeting zebrafish and murine pituitary corticotroph tumours with a cyclin-dependent kinase (CDK) inhibitor. PNAS doi: 10.1073/pnas.1018091108

About Cyclacel Pharmaceuticals, Inc.

Cyclacel is a biopharmaceutical company developing oral therapies that target the various phases of cell cycle control for the treatment of cancer and other serious diseases. Sapacitabine, Cyclacel’s most advanced product candidate, is the subject of SEAMLESS, a Phase 3 trial, which has completed enrollment and is being conducted under an SPA with the FDA as front-line treatment for acute myeloid leukemia (AML) in the elderly, and other indications including myelodysplastic syndromes (MDS). Cyclacel’s pipeline includes an oral regimen of seliciclib in combination with sapacitabine in a Phase 1 study of patients with Homologous Recombination (HR) repair-deficient breast, ovarian and pancreatic cancers, including gBRCA positive tumors, and CYC065, a novel CDK2/9 inhibitor, with potential utility in both hematological malignancies and solid tumors. Cyclacel’s strategy is to build a diversified biopharmaceutical business focused in hematology and oncology based on a development pipeline of novel drug candidates. Please visit www.cyclacel.com for more information.

Forward-looking Statements

This news release contains certain forward-looking statements that involve risks and uncertainties that could cause actual results to be materially different from historical results or from any future results expressed or implied by such forward-looking statements. Such forward-looking statements include statements regarding, among other things, the efficacy, safety and intended utilization of Cyclacel’s product candidates, the conduct and results of future clinical trials, plans regarding regulatory filings, future research and clinical trials and plans regarding partnering activities. Factors that may cause actual results to differ materially include the risk that product candidates that appeared promising in early research and clinical trials do not demonstrate safety and/or efficacy in larger-scale or later clinical trials, trials may have difficulty enrolling, Cyclacel may not obtain approval to market its product candidates, the risks associated with reliance on outside financing to meet capital requirements, and the risks associated with reliance on collaborative partners for further clinical trials, development and commercialization of product candidates. You are urged to consider statements that include the words “may,” “will,” “would,” “could,” “should,” “believes,” “estimates,” “projects,” “potential,” “expects,” “plans,” “anticipates,” “intends,” “continues,” “forecast,” “designed,” “goal,” or the negative of those words or other comparable words to be uncertain and forward-looking. For a further list and description of the risks and uncertainties the Company faces, please refer to the Company’s most recent Annual Report on Form 10-K and other periodic and other filings Cyclacel files with the Securities and Exchange Commission and are available at www.sec.gov. Such forward-looking statements are current only as of the date they are made, and Cyclacel assumes no obligation to update any forward-looking statements, whether as a result of new information, future events or otherwise.

© Copyright 2015 Cyclacel Pharmaceuticals, Inc. All Rights Reserved. The Cyclacel logo and Cyclacel® are trademarks of Cyclacel Pharmaceuticals, Inc.

Cyclacel Pharmaceuticals, Inc.

Company:
Paul McBarron, (908) 517-7330, 
Investor Relations:
Russo Partners LLC, Robert Flamm, (212) 845-4226

– See more at: http://globenewswire.com/news-release/2015/07/02/749361/10140470/en/First-Patient-Dosed-in-IST-of-CDK-Inhibitor-Seliciclib-in-Cushing-s-Disease-a-Serious-Endocrine-Disorder.html#sthash.KgdD65N9.dpuf

ALD403 (migraine drug) and ALD1613 (for Cushing’s disease)

As it moves into crucial Phase 3 drug trials for its flagship migraine treatment, Bothell-based Alder Biopharmaceuticals (Nasdaq: ALDR) is looking to raise a lot of cash.

Alder is offering up to $200 million shares of its common stock, according to SEC filings.

The company plans to use the money to develop its drugs ALD403 (its migraine drug) and ALD1613 (for Cushing’s disease), conduct clinical trials and commercialize these drugs. Funds will also go toward “general corporate purposes,” which might include the acquisition or licensing of other products, businesses or technologies, according to those filings.

From http://www.bizjournals.com/seattle/blog/health-care-inc/2015/06/alder-biopharmaceuticals-sets-out-to-raise-200m-to.html

Multiple aberrant hormone receptors in Cushing’s Syndrome

Eur J Endocrinol. 2015 May 13. pii: EJE-15-0200. [Epub ahead of print]
Multiple Aberrant Hormone Receptors in Cushing’s Syndrome.

Abstract

The mechanisms regulating cortisol production when ACTH of pituitary origin is suppressed in primary adrenal causes of Cushing’s syndrome include diverse genetic and molecular mechanisms. These can lead either to constitutive activation of the cAMP system and steroidogenesis or to its regulation exerted by the aberrant adrenal expression of several hormone receptors, particularly G-protein coupled hormone receptors (GPCR) and their ligands.

Screening for aberrant expression of GPCR in BMAH and unilateral adrenal tumors of patients with overt or subclinical CS demonstrates the frequent co-expression of several receptors. Aberrant hormone receptors can also exert their activity by regulating the paracrine secretion of ACTH or other ligands for those receptors in BMAH or unilateral tumors.

The aberrant expression of hormone receptors is not limited to adrenal Cushing’s syndrome but can be implicated in other endocrine tumors including primary aldosteronism and Cushing’s disease. Targeted therapies to block the aberrant receptors or their ligands could become useful in the future.

PMID:
25971648
[PubMed – as supplied by publisher]

Silibinin from milk thistle seeds as novel, non-invasive treatment strategy for Cushing Disease

Silibinin has an outstanding safety profile in humans and is currently used for the treatment of liver disease and poisoning. Scientists at the Max Planck Institute of Psychiatry in Munich discovered in collaboration with scientists from the Helmholtz Zentrum München in cell cultures, animal models and human tumor tissue that silibinin can be applied to treat Cushing Disease, a rare hormone condition caused by a tumor in the pituitary gland in the brain. The researchers have filed a patent and now plan clinical trials using silibinin as a non-invasive treatment strategy. Thus, in future, patients might not have to undergo brain surgery anymore.
Treatment with silibinin, a constituent of milk thistle seeds, alleviated symptoms of Cushing Disease in cell cultures, animal models and human tumor tissue. In future, patients might not have to undergo brain surgery anymore.

Cushing Disease, not to be confused with Cushing’s Syndrome, is caused by a tumor in the pituitary gland in the brain. The tumor secrets increased amounts of the stress hormone adrenocorticotropin (ACTH) followed by cortisol release from the adrenal glands leading to rapid weight gain, elevated blood pressure and muscular weakness. Patients are prone to osteoporosis and infections and may show cognitive dysfunction or even depression. In 80 to 85 % of the patients, the tumor can be removed by uncomfortable brain surgery. For inoperable cases, there is currently only one targeted therapy approved, which unfortunately causes intense side effects such as hyperglycemia in more than 20 % of the patients.

Scientists around Günter Stalla, endocrinologist at the Max Planck Institute of Psychiatry in Munich, have now discovered in cell cultures, animal models and human tumor tissue that a harmless plant extract can be applied to treat Cushing Disease. “Silibinin is the major active constituent of milk thistle seeds. It has an outstanding safety profile in humans and is already used for the treatment of liver disease and poisoning,” explains Marcelo Paez-Pereda, leading scientist of the current study published in the renowned scientific journal Nature Medicine. After silibinin treatment, tumor cells resumed normal ACTH production, tumor growth slowed down and symptoms of Cushing Disease disappeared in mice.

In 2013, the Max Planck scientists filed a patent on a broad family of chemical and natural compounds, including silibinin, to treat pituitary tumors. Compared to humans, where only 5.5 in 100,000 people worldwide develop Cushing Disease, this condition is very common in several pets. For example, 4 % of dogs and even 7 % of horses suffer from Cushing Disease. Thus, the researchers now plan to test special formulations with a very pure substance and slow release of the active component silibinin in clinical trials.

Silibinin: Mode of action

“We knew that Cushing Disease is caused by the release of too much ACTH. So we asked ourselves what causes this over production and how to stop it,” says Paez-Pereda. In their first experiments, the researchers found tremendously high amounts of the heat shock protein 90 (HSP90) in tumor tissue from patients with Cushing Disease. In normal amounts, HSP90 helps to correctly fold another protein, the glucocorticoid receptor, which in turn inhibits the production of ACTH. “As there are too many HSP90 molecules in the tumor tissue, they stick to the glucocorticoid receptor,” explains Paez-Pereda. “We found that silibinin binds to HSP90 thus allowing glucocorticoid receptor molecules to dissolve from HSP90. With silibinin, we might have discovered a non-invasive treatment strategy not only for the rare Cushing Disease but also for other conditions with the involvement of glucocorticoid receptors, such as lung tumors, acute lymphoblastic leukemia or multiple myeloma,” concludes Paez-Pereda.

From http://www.psych.mpg.de/2034377/PM1507