FDA accepts NDA for novel Cushing’s syndrome treatment

The FDA accepted for review a new drug application for the steroidogenesis inhibitor levoketoconazole for the treatment of  endogenous Cushing’s syndrome , according to an industry press release.

“We are pleased with the FDA’s acceptance for filing of the Recorlev new drug application,” John H. Johnson, CEO of Strongbridge Biopharma, said in the release. “We believe this decision reflects the comprehensive clinical evidence that went into the NDA submission, including the positive and statistically significant efficacy and safety results from the multinational phase 3 SONICS and LOGICS studies evaluating Recorlev as a potential treatment option for adults with endogenous Cushing’s syndrome. We are advancing our commercial readiness plans and look forward to potentially bringing a new therapeutic option to the Cushing’s syndrome community in the first quarter of 2022.”

As Healio previously reported, top-line findings from the LOGICS study demonstrated that levoketoconazole (Recorlev, Strongbridge Biopharma) improved and normalized morning urinary free cortisol concentrations for adults with endogenous Cushing’s disease compared with placebo.

The drug was generally well tolerated, with safety data mirroring those from the earlier phase 3 SONICS trial.

Endogenous Cushing’s syndrome — caused by chronic hypercortisolism — is rare, with estimates ranging from 40 to 70 people per million affected worldwide, according to the National Institute of Diabetes and Digestive and Kidney Diseases.

The FDA set a Prescription Drug User Fee Act target action date of Jan. 1, 2022, for levoketoconazole, according to the company. The FDA letter made no mention of a plan to hold an advisory committee meeting.

From https://www.healio.com/news/endocrinology/20210513/fda-accepts-nda-for-novel-cushings-syndrome-treatment

Cushing Death Rate ‘Unacceptable,’ Triple That of General Population

Excess mortality among people with endogenous Cushing syndrome (CS) has declined in the past 20 years yet remains three times higher than in the general population, new research finds.

Among more than 90,000 individuals with endogenous CS, the overall proportion of mortality ― defined as the ratio of the number of deaths from CS divided by the total number of CS patients ― was 0.05, and the standardized mortality rate was an “unacceptable” three times that of the general population, Padiporn Limumpornpetch, MD, reported on March 20 at ENDO 2021: The Endocrine Society Annual Meeting.

Excess deaths were higher among those with adrenal CS compared to those with Cushing disease. The most common causes of death among those with CS were cardiovascular diseases, cerebrovascular accident, infection, and malignancy, noted Limumpornpetch, of Songkla University, Hat Yai, Thailand, who is also a PhD student at the University of Leeds, Leeds, United Kingdom.

“While mortality has improved since 2000, it is still significantly compromised compared to the background population…. The causes of death highlight the need for aggressive management of cardiovascular risk, prevention of thromboembolism, infection control, and a normalized cortisol level,” she said.

Asked to comment, Maria Fleseriu, MD, told Medscape Medical News that the new data show “we are making improvements in the care of patients with CS and thus outcomes, but we are not there yet…. This meta-analysis highlights the whole spectrum of acute and life-threatening complications in CS and their high prevalence, even before disease diagnosis and after successful surgery.”

She noted that although she wasn’t surprised by the overall results, “the improvement over time was indeed lower than I expected. However, interestingly here, the risk of mortality in adrenal Cushing was unexpectedly high despite patients with adrenal cancer being excluded.”

Fleseriu, who is director of the Pituitary Center at Oregon Health and Science University, Portland, Oregon, advised, “Management of hyperglycemia and diabetes, hypertension, hypokalemia, hyperlipidemia, and other cardiovascular risk factors is generally undertaken in accordance with standard of clinical care.

“But we should focus more on optimizing more aggressively this care in addition to the specific Cushing treatment,” she stressed.

In addition, she noted, “Medical therapy for CS may be needed even prior to surgery in severe and/or prolonged hypercortisolism to decrease complications…. We definitely need a multidisciplinary approach to address complications and etiologic treatment as well as the reduced long-term quality of life in patients with CS.”

Largest Study in Scale and Scope of Cushing Syndrome Mortality

Endogenous Cushing syndrome occurs when the body overproduces cortisol. The most common cause of the latter is a tumor of the pituitary gland (Cushing disease), but another cause is a usually benign tumor of the adrenal glands (adrenal Cushing syndrome). Surgery is the mainstay of initial treatment of Cushing syndrome. If an operation to remove the tumor fails to cause remission, medications are available.

Prior to this new meta-analysis, there had been limited data on mortality among patients with endogenous CS. Research has mostly been limited to single-cohort studies. A previous systematic review/meta-analysis comprised only seven articles with 780 patients. All the studies were conducted prior to 2012, and most were limited to Cushing disease.

“In 2021, we lacked a detailed understanding of patient outcomes and mortality because of the rarity of Cushing syndrome,” Limumpornpetch noted.

The current meta-analysis included 91 articles that reported mortality among patients with endogenous CS. There was a total of 19,181 patients from 92 study cohorts, including 49 studies on CD (n = 14,971), 24 studies on adrenal CS (n = 2304), and 19 studies that included both CS types (n = 1906).

Among 21 studies that reported standardized mortality rate (SMR) data, including 13 CD studies (n = 2160) and seven on adrenal CS (n = 1531), the overall increase in mortality compared to the background population was a significant 3.00 (range, 1.15 – 7.84).

This SMR was higher among patients with adrenal Cushing syndrome (3.3) vs Cushing disease (2.8) (= .003) and among patients who had active disease (5.7) vs those whose disease was in remission (2.3) (< .001).

The SMR also was worse among patients with Cushing disease with larger tumors (macroadenomas), at 7.4, than among patients with very small tumors (microadenomas), at 1.9 (= .004).

The proportion of death was 0.05 for CS overall, with 0.04 for CD and 0.02 for adrenal adenomas.

Compared to studies published prior to the year 2000, more recent studies seem to reflect advances in treatment and care. The overall proportion of death for all CS cohorts dropped from 0.10 to 0.03 (P < .001); for all CD cohorts, it dropped from 0.14 to 0.03; and for adrenal CS cohorts, it dropped from 0.09 to 0.03 (P = .04).

Causes of death were cardiovascular diseases (29.5% of cases), cerebrovascular accident (11.5%), infection (10.5%), and malignancy (10.1%). Less common causes of death were gastrointestinal bleeding and acute pancreatitis (3.7%), active CS (3.5%), adrenal insufficiency (2.5%), suicide (2.5%), and surgery (1.6%).

Overall, in the CS groups, the proportion of deaths within 30 days of surgery dropped from 0.04 prior to 2000 to 0.01 since (P = .07). For CD, the proportion dropped from 0.02 to 0.01 (P = .25).

Preventing Perioperative Mortality: Consider Thromboprophylaxis

Fleseriu told Medscape Medical News that she believes hypercoagulability is “the least recognized complication with a big role in mortality.” Because most of the perioperative mortality is due to venous thromboembolism and infections, “thromboprophylaxis should be considered for CS patients with severe hypercortisolism and/or postoperatively, based on individual risk factors of thromboembolism and bleeding.”

Recently, Fleseriu’s group showed in a single retrospective study that the risk for arterial and venous thromboembolic events among patients with CS was approximately 20%. Many patients experienced more than one event. Risk was higher 30 to 60 days postoperatively.

The odds ratio of venous thromoboembolism among patients with CS was 18 times higher than in the normal population.

“Due to the additional thrombotic risk of surgery or any invasive procedure, anticoagulation prophylaxis should be at least considered in all patients with Cushing syndrome and balanced with individual bleeding risk,” Fleseriu advised.

A recent Pituitary Society workshop discussed the management of complications of CS at length; proceedings will be published soon, she noted.

Limumpornpetch commented, “We look forward to the day when our interdisciplinary approach to managing these challenging patients can deliver outcomes similar to the background population.”

Limumpornpetch has disclosed no relevant financial relationships. Fleseriu has been a scientific consultant to Recordati, Sparrow, and Strongbridge and has received grants (inst) from Novartis and Strongbridge.

ENDO 2021: The Endocrine Society Annual Meeting: Presented March 20, 2021

Miriam E. Tucker is a freelance journalist based in the Washington, DC, area. She is a regular contributor to Medscape. Other work of hers has appeared in the Washington Post, NPR’s Shots blog, and Diabetes Forecast magazine. She can be found on Twitter @MiriamETucker.

From https://www.medscape.com/viewarticle/949257

Largest-ever analysis of its kind finds Cushing’s syndrome triples risk of death

WASHINGTON–Endogenous Cushing’s syndrome, a rare hormonal disorder, is associated with a threefold increase in death, primarily due to cardiovascular disease and infection, according to a study whose results will be presented at ENDO 2021, the Endocrine Society’s annual meeting.

The research, according to the study authors, is the largest systematic review and meta-analysis to date of studies of endogenous (meaning “inside your body”) Cushing’s syndrome. Whereas Cushing’s syndrome most often results from external factors–taking cortisol-like medications such as prednisone–the endogenous type occurs when the body overproduces the hormone cortisol, affecting multiple bodily systems.

Accurate data on the mortality and specific causes of death in people with endogenous Cushing’s syndrome are lacking, said the study’s lead author, Padiporn Limumpornpetch, M.D., an endocrinologist from Prince of Songkla University, Thailand and Ph.D. student at the University of Leeds in Leeds, U.K. The study analyzed death data from more than 19,000 patients in 92 studies published through January 2021.

“Our results found that death rates have fallen since 2000 but are still unacceptably high,” Limumpornpetch said.

Cushing’s syndrome affects many parts of the body because cortisol responds to stress, maintains blood pressure and cardiovascular function, regulates blood sugar and keeps the immune system in check. The most common cause of endogenous Cushing’s syndrome is a tumor of the pituitary gland called Cushing’s disease, but another cause is a usually benign tumor of the adrenal glands called adrenal Cushing’s syndrome. All patients in this study had noncancerous tumors, according to Limumpornpetch.

Overall, the proportion of death from all study cohorts was 5 percent, the researchers reported. The standardized mortality ratio–the ratio of observed deaths in the study group to expected deaths in the general population matched by age and sex–was 3:1, indicating a threefold increase in deaths, she stated.

This mortality ratio was reportedly higher in patients with adrenal Cushing’s syndrome versus Cushing’s disease and in patients who had active disease versus those in remission. The standardized mortality ratio also was worse in patients with Cushing’s disease with larger tumors versus very small tumors (macroadenomas versus microadenomas).

On the positive side, mortality rates were lower after 2000 versus before then, which Limumpornpetch attributed to advances in diagnosis, operative techniques and medico-surgical care.

More than half of observed deaths were due to heart disease (24.7 percent), infections (14.4 percent), cerebrovascular diseases such as stroke or aneurysm (9.4 percent) or blood clots in a vein, known as thromboembolism (4.2 percent).

“The causes of death highlight the need for aggressive management of cardiovascular risk, prevention of thromboembolism and good infection control and emphasize the need to achieve disease remission, normalizing cortisol levels,” she said.

Surgery is the mainstay of initial treatment of Cushing’s syndrome. If an operation to remove the tumor fails to put the disease in remission, other treatments are available, such as medications.

Study co-author Victoria Nyaga, Ph.D., of the Belgian Cancer Centre in Brussels, Belgium, developed the Metapreg statistical analysis program used in this study.

###

Endocrinologists are at the core of solving the most pressing health problems of our time, from diabetes and obesity to infertility, bone health, and hormone-related cancers. The Endocrine Society is the world’s oldest and largest organization of scientists devoted to hormone research and physicians who care for people with hormone-related conditions.

The Society has more than 18,000 members, including scientists, physicians, educators, nurses and students in 122 countries. To learn more about the Society and the field of endocrinology, visit our site at http://www.endocrine.org. Follow us on Twitter at @TheEndoSociety and @EndoMedia.

Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.

From https://www.eurekalert.org/pub_releases/2021-03/tes-lao031621.php

New Drug Application for RECORLEV® (levoketoconazole) for the Treatment of Endogenous Cushing’s Syndrome

~ RECORLEV® (levoketoconazole) New Drug Application is Supported by Previously-Reported Positive and Statistically Significant Results from the Phase 3 SONICS and LOGICS Studies ~

~ Nearly 40 Percent of Prescription-Treated Endogenous Cushing’s Syndrome Patients in the U.S. Are Not Well-Controlled, Underscoring Need for New, Safe and Effective Pharmaceutical Options to Help Regulate Cortisol Levels ~

~ If Approved Following a Projected 10-Month Review Cycle, RECORLEV is Anticipated to Launch in First Quarter of 2022 ~

DUBLIN, Ireland and TREVOSE, Pa., March 02, 2021 (GLOBE NEWSWIRE) — Strongbridge Biopharma plc, (Nasdaq: SBBP), a global commercial-stage biopharmaceutical company focused on the development and commercialization of therapies for rare diseases with significant unmet needs, today announced that it submitted a New Drug Application (NDA) for RECORLEV® (levoketoconazole) for the treatment of endogenous Cushing’s syndrome to the U.S. Food and Drug Administration (FDA). The submission is supported by previously reported positive and statistically significant results of the SONICS and LOGICS trials: two Phase 3 multinational studies designed to evaluate the safety and efficacy of RECORLEV when used to treat adults with endogenous Cushing’s syndrome.

“The submission of the New Drug Application for RECORLEV® (levoketoconazole) represents not only a significant milestone for Strongbridge but also for the Cushing’s syndrome community as a whole. As an organization focused on developing treatments for underserved rare disease patient populations, we are one step closer to helping address the needs of the estimated 8,000 Cushing’s syndrome patients in the U.S. who are treated with prescription therapy, many of whom, as we learned in our market research, are not well-controlled with current therapies,” said John H. Johnson, chief executive officer of Strongbridge Biopharma. “We look forward to working with the FDA through their review of our application, and we are actively preparing for the potential launch of RECORLEV in the first quarter of 2022, if approved.”

RECORLEV, the pure 2S,4R enantiomer of the enantiomeric pair comprising ketoconazole, is a next-generation steroidogenesis inhibitor being investigated as a chronic therapy for adults with endogenous Cushing’s syndrome. Two Phase 3 studies have demonstrated substantial evidence of efficacy and safety in a combined study population of 166 patients that was representative of the adult drug-treated U.S. population with Cushing’s syndrome. The SONICS study met its primary and key secondary endpoints, demonstrating a statistically significant rate of mean urinary free cortisol normalization after six months of maintenance therapy without a dose increase (detailed results here). LOGICS, a double-blind, placebo-controlled randomized-withdrawal study, which also had statistically significant primary and key secondary endpoints, confirmed that the long-term cortisol-normalizing efficacy demonstrated in SONICS was due to use of levoketoconazole specifically (detailed results here). The long-term open-label extension study, OPTICS, is contributing safety information to the NDA.

“We want to thank the patients, their families, investigators, collaborators, and employees who have contributed to the RECORLEV clinical program leading to this important regulatory milestone,” said Fredric Cohen, M.D., chief medical officer of Strongbridge Biopharma.

RECORLEV has received orphan drug designation from the FDA and the European Medicines Agency for the treatment of endogenous Cushing’s syndrome.

Strongbridge will host a conference call tomorrow, Wednesday, March 3, 2021 at 8:30 a.m. ET to discuss the Company’s fourth quarter and full-year 2020 financial results and recent corporate highlights, including the RECORLEV NDA submission.

About Cushing’s Syndrome
Endogenous Cushing’s syndrome is a rare, serious and potentially lethal endocrine disease caused by chronic elevated cortisol exposure – often the result of a benign tumor of the pituitary gland. This benign tumor tells the body to overproduce high levels of cortisol for a sustained period of time, and this often results in undesirable physical changes. The disease is most common among adults between the ages of 30 to 50, and it affects women three times more often than men. Women with Cushing’s syndrome may experience a variety of health issues including menstrual problems, difficulty becoming pregnant, excess male hormones (androgens), primarily testosterone which can cause hirsutism (growth of coarse body hair in a male pattern), oily skin, and acne. Additionally, the internal manifestations of the disease are potentially life threatening. These include metabolic changes such as high blood sugar, or diabetes, high blood pressure, high cholesterol, fragility of various tissues including blood vessels, skin, muscle and bone, and psychologic disturbances such as depression, anxiety and insomnia. Untreated, the five-year survival rate is only approximately 50 percent.

About the SONICS Study
SONICS is an open-label, Phase 3 study of RECORLEV as a treatment for endogenous Cushing’s syndrome that enrolled 94 patients at centers in North America, Europe and the Middle East. Following a screening phase, SONICS has three treatment phases: (1) Dose Titration Phase: Patients started RECORLEV at 150 mg twice daily (300 mg total daily dose) and titrated in 150 mg increments with the goal of achieving a therapeutic dose – a dose resulting in mUFC normalization – at which point titration was stopped; (2) Maintenance Phase: The dose was fixed and should not have been changed other than for safety reasons or loss of efficacy. At the end of the six-month maintenance phase, the mUFC response rate was measured; and (3) Extended Evaluation Phase: Patients continued on RECORLEV for another six months to evaluate long-term safety and tolerability and explore efficacy durability.

About the LOGICS Study
The Phase 3, multinational, double-blind, placebo-controlled, randomized-withdrawal study, LOGICS, randomized Cushing’s syndrome patients with baseline mean urinary free cortisol (mUFC) at least 1.5 times the upper limit of normal (ULN) following completion of a single-arm, open-label treatment phase of approximately 14 to 19 weeks, with RECORLEV individually titrated according to mUFC response.

A total of 79 patients were dosed during the open-label titration-maintenance phase, 7 of whom had previously received RECORLEV during the SONICS study, and 72 who had not previously received RECORLEV. At study baseline, the median mUFC was 3.5 times the ULN, indicative of significant hypercortisolemia.

A total of 44 patients (39 who had completed the titration-maintenance phase and five who directly enrolled from the SONICS study), were randomized to either continue RECORLEV (n=22) or to have treatment withdrawn by receiving a matching placebo regimen (n=22) for up to 8 weeks, followed by restoration to the prior regimen using blinded drug. Of the 44 patients randomized, 11 patients (25 percent) had previously received RECORLEV during the SONICS study. Patients who required rescue treatment with open-label RECORLEV during the randomized-withdrawal phase were considered to have lost mUFC response at the visit corresponding to their first dose of rescue medication. Patients who did not qualify for randomization were removed from open-label treatment prior to randomization and excused from the study.

About RECORLEV
RECORLEV® (levoketoconazole) is an investigational cortisol synthesis inhibitor in development for the treatment of patients with endogenous Cushing’s syndrome, a rare but serious and potentially lethal endocrine disease caused by chronic elevated cortisol exposure. RECORLEV is the pure 2S,4R enantiomer of ketoconazole, a steroidogenesis inhibitor. RECORLEV has demonstrated in two successful Phase 3 studies to significantly suppress serum cortisol and has the potential to be a next-generation cortisol inhibitor.

The Phase 3 program for RECORLEV includes SONICS and LOGICS: two multinational studies designed to evaluate the safety and efficacy of RECORLEV when used to treat endogenous Cushing’s syndrome. The SONICS study met its primary and secondary endpoints, demonstrating a statistically significant normalization rate of urinary free cortisol at six months. The LOGICS study, which met its primary endpoint, is a double-blind, placebo-controlled randomized-withdrawal study of RECORLEV that is designed to supplement the long-term efficacy and safety information supplied by SONICS. The ongoing long-term open label OPTICS study will gather further useful information related to the long-term use of RECORLEV.

RECORLEV has received orphan drug designation from the FDA and the European Medicines Agency for the treatment of endogenous Cushing’s syndrome.

About Strongbridge Biopharma
Strongbridge Biopharma is a global commercial-stage biopharmaceutical company focused on the development and commercialization of therapies for rare diseases with significant unmet needs. Strongbridge’s rare endocrine franchise includes RECORLEV® (levoketoconazole), a cortisol synthesis inhibitor currently being studied in Phase 3 clinical studies for the treatment of endogenous Cushing’s syndrome, and veldoreotide extended release, a pre-clinical next-generation somatostatin analog being investigated for the treatment of acromegaly and potential additional applications in other conditions amenable to somatostatin receptor activation. Both RECORLEV and veldoreotide have received orphan drug designation from the FDA and the European Medicines Agency. The Company’s rare neuromuscular franchise includes KEVEYIS® (dichlorphenamide), the first and only FDA-approved treatment for hyperkalemic, hypokalemic, and related variants of primary periodic paralysis. KEVEYIS has orphan drug exclusivity in the United States.

Forward-Looking Statements
This press release contains forward-looking statements within the meaning of the federal securities laws. The words “anticipate,” “estimate,” “expect,” “intend,” “may,” “plan,” “potential,” “project,” “target,” “will,” “would,” or the negative of these terms or other similar expressions are intended to identify forward-looking statements, although not all forward-looking statements contain these identifying words. All statements, other than statements of historical facts, contained in this press release, are forward-looking statements, including statements related to data from the LOGICS and SONICS studies, the potential advantages of RECORLEV, the anticipated timing for potential approval of a marketing authorization for RECORLEV and for the potential launch of RECORLEVStrongbridge’s strategy, plans, outcomes of product development efforts and objectives of management for future operations. Forward-looking statements involve risks and uncertainties that could cause actual results to differ materially from those expressed in such statement, including risks and uncertainties associated with clinical development and the regulatory approval process, the reproducibility of any reported results showing the benefits of RECORLEV, the adoption of RECORLEV by physicians, if approved, as treatment for any disease and the emergence of unexpected adverse events following regulatory approval and use of the product by patients. Additional risks and uncertainties relating to Strongbridge and its business can be found under the heading “Risk Factors” in Strongbridge’s Annual Report on Form 10-K for the year ended December 31, 2019 and its subsequent Quarterly Reports on Form 10-Q, as well as its other filings with the SEC. These forward-looking statements are based on current expectations, estimates, forecasts and projections and are not guarantees of future performance or development and involve known and unknown risks, uncertainties and other factors. The forward-looking statements contained in this press release are made as of the date of this press release, and Strongbridge Biopharma does not assume any obligation to update any forward-looking statements except as required by applicable law.

Contacts:

Corporate and Media Relations
Elixir Health Public Relations
Lindsay Rocco
+1 862-596-1304
lrocco@elixirhealthpr.com

Investor Relations
Solebury Trout
Mike Biega
+1 617-221-9660
mbiega@soleburytrout.com

 

From https://www.biospace.com/article/releases/strongbridge-biopharma-plc-announces-submission-of-new-drug-application-for-recorlev-levoketoconazole-for-the-treatment-of-endogenous-cushing-s-syndrome-to-the-u-s-food-and-drug-administration/

The Effect of Biochemical Remission on Bone Metabolism in Cushing’s Syndrome: A 2‐Year Follow‐Up Study

https://doi.org/10.1002/jbmr.4033

 

ABSTRACT

Endogenous Cushing’s syndrome (CS) is a rare cause of secondary osteoporosis. The long‐term consequences for bone metabolism after successful surgical treatment remain largely unknown. We assessed bone mineral density and fracture rates in 89 patients with confirmed Cushing’s syndrome at the time of diagnosis and 2 years after successful tumor resection. We determined five bone turnover markers at the time of diagnosis, 1 and 2 years postoperatively. The bone turnover markers osteocalcin, intact procollagen‐IN‐propeptide (PINP), alkaline bone phosphatase, CTX‐I, and TrAcP 5b were measured in plasma or serum by chemiluminescent immunoassays. For comparison, 71 sex‐, age‐, and body mass index (BMI)‐matched patients in whom Cushing’s syndrome had been excluded were studied. None of the patients received specific osteoanabolic treatment. At time of diagnosis, 69% of the patients had low bone mass (mean T‐score = −1.4 ± 1.1). Two years after successful surgery, the T‐score had improved in 78% of patients (mean T‐score 2 years postoperatively −1.0 ± 0.9). The bone formation markers osteocalcin and intact PINP were significantly decreased at time of diagnosis (p ≤ 0.001 and p = 0.03, respectively), and the bone resorption marker CTX‐I and TrAcP 5b increased. Postoperatively, the bone formation markers showed a three‐ to fourfold increase 1 year postoperatively, with a moderate decline thereafter. The bone resorption markers showed a similar but less pronounced course. This study shows that the phase immediately after surgical remission from endogenous CS is characterized by a high rate of bone turnover resulting in a striking net increase in bone mineral density in the majority of patients. © 2020 The Authors. Journal of Bone and Mineral Research published by American Society for Bone and Mineral Research.

Introduction

Cushing’s syndrome (CS) is a rare disease with approximately 0.7 to 2.4 new cases per 1 million per year.1 Osteoporosis and osteopenia are typical comorbidities of patients with endogenous and exogenous CS. Depending on the study, 60% to 80% of patients have evidence for a reduced bone mineral density2 characteristically affecting the entire skeleton.3 About 5% of all cases of secondary osteoporosis are caused by hypercortisolism.4 However, data from prospective, well‐powered studies are rare, and few risk factors that would predict bone health have been identified so far. Guidelines for the management of osteoporosis due to endogenous CS are still missing.5 In terms of risk assessment, the subtype of CS does not seem to influence osteoporosis risk,6 whereas the morning cortisol levels are negatively correlated with lumbar bone mineral density.6 The duration of endogenous Cushing’s syndrome (or the duration of exogenous replacement therapy after successful surgery) obviously affects bone mineral density.7 Whether the T‐score is the best predictor for fracture risk is not quite clear.2

Another area of uncertainty is the natural course of osteoporosis and bone turnover markers once the diagnosis of Cushing’s syndrome has been established. A number of studies have addressed this topic, but the interpretation of the results is hampered because of limited patient numbers, concomitant osteoanabolic treatment, or both.810 In‐depth insight on bone remodeling in CS might come from bone turnover marker studies. For example, the bone formation marker osteocalcin is suppressed in untreated CS,3 a consistent observation making it useful as a diagnostic marker for CS.2

Based on the paucity of data, the lack of evidence for treatment guidelines, and the pressing open questions regarding risk assessment and management of osteoporosis, we performed a sufficiently powered study to analyze the natural course of bone turnover and bone mineral density in a monocentric cohort of patients with endogenous Cushing’s syndrome. To the best of our knowledge, this is the first such study, and the data obtained will be instrumental for clinicians who care for patients with Cushing’s syndrome.

Materials and Methods

Patients

This study was performed as part of the prospective German Cushing registry, which has included 450 consecutive patients referred to our department for suspected CS since 2012. Structure and general characteristics of the registry have been described in detail previously.1114 All patients included in the registry underwent a standardized biochemical screening and clinical examination at time of diagnosis and a yearly follow‐up after treatment to treat comorbidities and diagnose recurrence of the disease early.

In all patients, standard screening for CS with a 1 mg low‐dose overnight dexamethasone suppression test (LDDST), collection of 24‐hour urine (UFC), and sampling of midnight salivary cortisol were performed. When the diagnosis of CS was confirmed, further subtyping was based on plasma adrenocorticotropic hormone (ACTH), corticotropin‐releasing hormone (CRH) test, high‐dose dexamethasone suppression test, imaging, and inferior petrosal sinus sampling (in case of ACTH dependence). Final diagnosis was CS in 156 patients and exclusion of CS in the remaining 294 patients. Patients with excluded CS were a quite heterogenic group with lead symptoms such as obesity (73%), arterial hypertension (50%), or hirsutism (33%). Final diagnoses in these subjects were metabolic syndrome, polycystic ovary syndrome (PCOS), obesity, depression, or primary hyperaldosteronism. Patient selection is shown in Fig. 1.

image
Patient selection. *Very young age; patient conducted densitometry in a different clinic/outpatient clinic; patient refused densitometry. CS = Cushing’s syndrome; BMD = bone mineral density; BMI = body mass index. Bold text indicates actual cohort of the study.

In our analysis, we excluded patients for whom no densitometry data were available (n = 63) and patients receiving pharmacologic treatment for osteoporosis following diagnosis (n = 4). Densitometry data were not available for multiple reasons (very young age, external densitometry in a different clinic, missing consent to perform densitometry).

We matched the remaining 89 patients with 71 controls subjects selected from those subjects in whom CS was excluded. Matching was done according to sex, age, and body mass index (BMI). None of the patients and controls received specific osteoanabolic or antiresorptive treatment, but 47% of patients with CS received vitamin D supplementation after remission. At time of diagnosis, 11% of controls and 17% of patients with CS received vitamin D supplementation.

Methods

In patients with confirmed CS, a bone mineral densitometry was conducted. Bone mineral density (BMD) was determined at the lumbar spine and the femur (neck and total femur).

If a reduced bone mineral density was diagnosed, a follow‐up densitometry was performed 2 years after surgery. If bone mineral density was normal initially or during follow‐up, only one further densitometry was performed 2 or 3 years after initial diagnosis. An improvement or decrease of bone mineral density was defined according to the least significant change (LSC = 2.8 × 1.8%).15 Accordingly, an alteration of more than 5.04% of BMD was rated as significant. A detailed fracture history was taken and X‐ray of the spine was performed when clinical suspicion for fractures was high.

In all patients, blood samples (serum and plasma) were taken at time of diagnosis and also 1 and 2 years after successful transsphenoidal surgery or adrenalectomy. Blood was taken in the fasting state between 8:00 and 10:00 a.m. Samples were centrifuged within 20 minutes at 4°C and stored at −80° until assayed. Three bone formation markers and two bone resorption markers were measured: osteocalcin, intact procollagen I‐N‐propeptide (PINP), and bone alkaline phosphatase (BAP) as bone formation markers, and CrossLaps (CTX‐I) and tartrate‐resistant acid phosphatase (5b TrAcP5b) as bone resorption marker, on basis of published data demonstrating their usefulness in CS and primary osteoporosis.216

Samples were measured at the Endocrine Laboratory of the Department of Internal Medicine IV on the iSYS automated analyzer (IDS‐iSYS, Boldon, UK) by well‐validated assays.1718 Published, method‐specific reference intervals are available from a large healthy population.1920 For the determination of osteocalcin, an N‐MID assay was used, as pre‐analytics are less critical in this assay.21 TrAcp 5b is a new marker, which, in contrast to CTX‐1, can also reliably be measured in the non‐fasting state.22

Statistical analysis

In a priori power analysis, we calculated that a total sample size of 102 would be sufficient to identify significant differences between groups, assuming a medium effect size (0.5), a power of 1 – β = 0.80 and a type I error of α = 0.05, with 51 subjects having Cushing’s syndrome and 51 subjects being control subjects after excluding Cushing’s syndrome.

For statistical analysis, SPSS 25 (IBM Corp., Armonk, NY, USA) was used. Clinical characteristics are shown as mean and standard deviation when data is normal distributed; otherwise as median and ranges. Because of the lack of normal distribution of bone turnover markers, nonparametric tests were used to test differences between groups. Differences between bone turnover markers at different times were tested by Friedman test. Multiple regression analysis was used to investigate differences between CS and the control group regarding bone turnover markers adjusted for sex, age, and BMI. Any p values < 0.05 were considered to indicate statistical significance.

Results

Patient characteristics

The clinical and biochemical characteristics of the patient sample are summarized in Table 1. Sixty‐five percent of patients had pituitary CS, 28% adrenal, and 7% suffered from ectopic CS. Patients and controls were well‐matched regarding sex, age, and vitamin D levels and supplementation, but differed in terms of diabetes prevalence.

Table 1. Clinical and Biochemical Baseline Characteristics of Patients with Cushing’s Syndrome (CS) and Control Subjects in Whom CS Has Been Excluded
CS at time of diagnosis (n = 89) CS excluded (n = 71) p Value
Sex 66 women (74%), 23 men (26%) 53 women (75%), 18 men (25%) 0.94
Age (years) 44 ± 13 43 ± 14 0.56
BMI 30 ± 7 31 ± 6 0.11
Vitamin D (ng/mL) 24 ± 10 24 ± 12 0.59
Vitamin D supplementation 17% 11% 0.37
Diabetes mellitus 30% (26) 11% (7) 0.007
Morning serum cortisol (μg/dL) 18 (11.7–24.9) 8.4 (5.9–11.6) ≤0.001
LDDST (μg/dL) 14.7 (7.7–23.7) 1.0 (0.8–1.2) ≤0.001
UFC (μg/24 h) 587 (331–843) 140 (78–216) ≤0.001
ACTH (pg/mL) 47 (9–76) 13 (9–18) ≤0.001
Late‐night salivary cortisol (ng/mL) 7.9 (3.3–11.8) 1.2 (0.6–1.8) ≤0.001
Bone turnover markers
Osteocalcin (ng/mL) 8 (5–13) 13 (10–17) <0.001
PINP (ng/mL) 35 (29–62) 52 (35–73) 0.025
BAP (μg/L) 23 (16–31) 17 (14–24) 0.006
CTX‐I (ng/mL) 0.28 (0.17–0.42) 0.23 (0.12–0.32) 0.033
TrAcP (U/L) 2.3 (1.7–3.4) 1.9 (1.3–2.4) 0.009
  • Date are shown as mean ± standard deviation or median and ranges.
  • BMI = body mass index; LDDST = low‐dose dexamethasone suppression test; UFC = urinary free cortisol; ACTH = adrenocorticotropic hormone; PINP = intact procollagen I‐N‐propeptide; BAP = bone alkaline phosphatase; CTX‐I = CrossLaps; TrAcP = tartrate‐resistant acid phosphatase. Bold numbers indicate statistical significance.

Baseline evaluation

At time of diagnosis, the mean levels of bone formation markers osteocalcin and intact PINP were significantly decreased compared with the controls, and the bone formation marker bone alkaline phosphatase was increased (Table 1; Fig. 2). Both bone degradation markers CTX and TrAcP were increased (Table 1). Taken together, this demonstrates increased bone resorption and decreased bone formation in florid CS. Results of multiple linear regression analysis comparing Cushing’s syndrome patients and controls are shown in Table 2. Bone markers were similar in patients with a reduced bone mass versus those with a normal bone mass (data not shown).

image
Bone turnover markers and bone mineral density at baseline and 1 and 2 years after remission. Boxplot = median and ranges of bone turnover marker in patients with Cushing’s syndrome.Gray box = median and ranges of bone turnover markers in the control group.PINP = procollagen I‐N‐propeptide; BAP = bone alkaline phosphatase; TrAcP = tartrate‐resistant acid phosphatase; CTX‐I = CrossLaps.
Table 2. Results of Multiple Linear Regression Analysis Comparing Cushing’s Syndrome Patients Versus Controls
Dependent variable Standardized regression coefficient and p value for group variable
Unadjusted Adjusted for age, sex, and BMI
Osteocalcin (ng/mL) −0.392, 0.006 −0.375, 0.010
PINP (ng/mL) −0.215, 0.204 −0.256, 0.145
BAP (μg/L) 0.404, 0.001 0.470, <0.001
CTX‐I (ng/mL) 0.111, 0.366 0.065, 0.616
TrAcP (U/L) 0.227, 0.014 0.186, 0.069
  • PINP = procollagen I‐N‐propeptide; BAP = bone alkaline phosphatase; CTX‐I = CrossLaps; TrAcP = tartrate‐resistant acid phosphatase. Bold numbers indicate statistical significance.

Overall, bone mineral density was decreased with an average lowest T‐score of −1.4 (±1.1). BMD was significantly lower (p = 0.001) at the femoral neck (T‐score = −0.9 ± 1.0) and the spine (T‐score = −1.0 ± 1.5) compared with the total femur (T‐score = −0.5 ± 1.2). Twenty‐eight patients (32%) had a normal bone mineral density, 46 (52%) osteopenia, and the other 15 patients (17%) osteoporosis with a T‐score lower than −2.5.

Seventeen of the patients (19%) had a history of low‐trauma osteoporotic fractures (9 vertebral fractures, 8 nonvertebral fractures). The fractures took place shortly before diagnosis (58%) or more than 2 years before diagnosis of the CS (42%). Patients with osteoporotic fractures had a significantly lower T‐score than patients without fractures (T‐score = −1.9 ± 0.8 versus −1.3 ± 1.1, p = 0.03) but did not differ in the values of the bone turnover markers or standard biochemical screening. Subtype, age, or BMI also did not differ between groups. However, men were significantly at higher risk of having fractures than women (35% of men had fractures versus 14% of women, p = 0.03). Both severity of hypercortisolism and duration of CS did not contribute to fractures rates (data not shown), but UFC was significantly higher in patients with a T‐score lower than −1.5 (Table 3).

Table 3. Biochemical Markers in Patients With Cushing’s Syndrome With a T‐Score Lower Than −1.5 and Above −1.5 Shown in Median and Ranges
Variable T‐score < −1.5 (n = 39) T‐score ≥ −1.5 (n = 42) p Values
LDDST (μg/dL) 16.6. (10.3–28.3) 11.9 (6.1–21.9) 0.12
UFC (μg/24 h) 706 (410–906) 398 (285–787) 0.03
Late‐night salivary cortisol (ng/mL) 8.3 (3.5–13.6) 5.7 (2.9–11.7) 0.39
ACTH (pg/mL) 53 (16–73) 42 (6–82) 0.88
  • LDDST = low‐dose dexamethasone suppression test; UFC = urinary free cortisol; ACTH = adrenocorticotropic hormone. Bold numbers indicate statistical significance.

One‐ and 2‐year follow‐up

Surgical tumor resection leading to biochemical remission of CS resulted in a strong increase of bone formation markers tested at 1‐year follow‐up (Table 4; Fig. 2AB). After 2 years, the markers had decreased slightly but remained elevated. Bone resorption markers were mildly increased at time of diagnosis, increased further at 1 year post‐surgery, and returned almost to normal levels at 2 years (Table 4; Fig. 2DE). A follow‐up bone densitometry conducted in 40 patients showed a parallel increase of the T‐score of 0.6 ± 0.8 (Fig. 2F). In particular, BMD of the spine improved (Table 5).

Table 4. Bone Turnover Markers and Bone Mass in Patients With Cushing’s Syndrome at Time of Diagnosis and During 2 Years of Follow‐Up
Time of diagnosis (n = 50) 1 year in remission (n = 45) 2 years in remission (n = 38) p (0 versus 1) p (0 versus 2) p (1 versus 2)
T‐score −1.5 (−2.0 to −0.8) −1.1 (−1.5 to −0.4) <0.001
Osteocalcin (ng/mL) 8 (5–13) 30 (14–60) 21 (13–31) <0.001 0.008 0.3
PINP (ng/mL) 35 (29–62) 117 (52–221) 69 (46–113) <0.001 0.1 0.1
BAP (μg/L) 23 (16–31) 26 (19–38) 22 (15–31) 0.2 0.4 0.1
CTX‐I (ng/mL) 0.28 (0.17–0.42) 0.51 (0.22–0.91) 0.25 (0.18–0.73) 0.01 0.1 0.04
TrAcP (U/L) 2.3 (1.7–3.4) 2.8 (1.8–4.0) 2.3 (2–3.2) 0.1 0.6 0.002
  • PINP = procollagen I‐N‐propeptide; BAP = bone alkaline phosphatase; CTX‐I = CrossLaps; TrAcP = tartrate‐resistant acid phosphatase. Bold numbers indicate statistical significance.
Table 5. Overview: T‐Scores, Z‐Scores, and BMD Values With Percent Changes (Mean and Standard Deviation)
Variable CS at time of diagnosis CS 2 years in remission p Values, percent changes (↑)
Femoral neck
T‐score femoral neck −0.81 ± 0.97 −0.59 ± 0.86 0.06
Z‐score femoral neck −0.59 ± 0.98 −0.28 ± 0.79 0.02
BMD (g/cm2) femoral neck 0.91 ± 0.12 0.95 ± 0.12 0.16; 4% ↑
Femur
T‐score femur −0.49 ± 1.11 −0.42 ± 1.04 0.67
Z‐score femur −0.40 ± 1.04 −0.37 ± 0.85 0.31
BMD (g/cm2) femur 0.95 ± 0.15 0.97 ± 0.14 0.77, 2% ↑
Spine
T‐score spine −0.96 ± 1.56 −0.55 ± 1.25 <0.001
Z‐score spine −0.85 ± 1.53 −0.58 ± 1.14 <0.001
BMD (g/cm2) spine 1.08 ± 0.22 1.13 ± 0.15 0.001, 0.6% ↑
  • BMD = bone mineral density; CS = Cushing’s syndrome. Bold numbers indicate statistical significance.

In 78% of patients, bone mineral density improved after 2 years; in 45% of patients, T‐score improved more than 0.5. No clinical fractures occurred after successful treatment of the CS. There was no significant correlation between improvement of bone mineral density and any of the bone turnover markers.

Discussion

This study investigated for the first time to our knowledge a panel of bone formation and resorption markers in a large cohort of patients with CS over the long term. The unique and comprehensive data show that initially bone metabolism is characterized by decreased bone formation and increased bone resorption, in line with the classical action of glucocorticoids. Successful treatment of endogenous Cushing’s syndrome leads to a strong activation of bone turnover, characterized by increased bone formation and bone resorption, a process that is continuous beyond year 2 after remission of CS, although at a reduced activity level. In parallel, bone mineral density increases in the majority of patients. Although 19% had low‐trauma fractures at baseline, none of the subjects experienced clinical fractures during follow‐up. In summary, these data give new insight into bone healing after remission of CS. They strongly suggest that an observational approach to the bone phenotype is justified as long as remission from CS is secured.

Reversibility of osteoporosis and bone turnover markers

Although established in osteoporosis research, bone turnover markers are not measured on a routine basis in patients with CS. However, it is a consistent result from different studies that osteocalcin is depressed in patients with CS. In fact, this finding is so reliable that it was even suggested to use osteocalcin in the diagnosis of CS.2 P1NP and procollagen carboxy‐terminal propeptide (P1CP) have also been studied in several studies, with contradictory results.23 In a retrospective study with 21 patients with CS, it was shown that osteocalcin is depressed; this applies also for PINP, whereas CTX is increased.24

Some studies already have focused on the reversibility of osteoporosis after treatment of CS. In the majority of patients, bone mineral density increased within 2 years after successful treatment81025 Hermus and colleagues showed in a study with 20 patients that bone mineral density did not change 3 or 6 months after surgery but increased thereafter in almost all patients.8 In a study with 68 patients, the patients were followed up for 4 years. Bone mineral density increased over lumbar spine and femur but decreased at the forearm.25 The authors concluded that bone minerals were redistributed from the peripheral to the axial skeleton.

In our study, bone mineral density also improved in the majority of patients but remained reduced in some. We did not find any difference in bone turnover markers between patients with improvement and without improvement.

Current treatment guidelines and treatment suggestions

As observed in our study, bone formation markers increase significantly after surgical cure, whereas bone degradation markers are mildly elevated at baseline and increase slightly at 1 year, returning within the normal range at 2 years. So far, there is no international guideline on the treatment of osteoporosis induced by endogenous CS and very few controlled interventional studies. In an opinion paper, Scillitani and colleagues recommended to treat all patients with vitamin D and calcium but not with bisphosphonates.5 In a randomized open‐label study by Di Somma and colleagues,26 39 patients (18 patients with active CS and 21 patients with CS in remission) received alendronate or no medication. Patients with active CS also received ketoconazole to control hypercortisolism. Bone mineral density improved and serum levels of osteocalcin increased in patients who received alendronate to a greater extent than those receiving no alendronate.

In a small study by the same research group,27 15 patients with CS (9 adolescent patients and 6 adults) were observed for 2 years after successful treatment, showing that osteocalcin levels and bone mineral density increased significantly.

Strengths and limitations

Although this study has several strengths, including the large prospective design and measuring a panel of bone formation and resorption markers, there are a few limitations. Some asymptomatic fractures may have been overlooked because an X‐ray was not taken systematically in each patient. Furthermore, a follow‐up bone densitometry was not available for all patients. Additionally, patients in the control group suffered from diabetes, overweight, arterial hypertension, or other diseases.

Novel aspects and outlook

This study analyzes for the first time in a comprehensive way bone turnover markers during the course of CS. The data show that cure from CS leads to increases in bone remodeling and bone mineral density, in line with spontaneous “bone healing.” Our data support a wait‐and‐watch strategy despite a high endogenous risk for additional fractures, based on the baseline assessment. This observation will influence future therapeutic strategies in patients with CS.

Our data suggest that the phase immediately after remission from CS is characterized by a high rate of bone turnover, resulting in a spontaneous net increase in bone mineral density in the majority of patients. Both bone attachment and bone degradation markers increase significantly, leading to an increase in bone mass and to a reduced risk of osteoporotic fractures. This unconstrained increase in bone formation markers after remission should be considered before specific therapy is initiated. Our data do not favor specific pharmacologic interventions with bisphosphonates or denosumab during this phase of remodeling because they may disrupt the osteoblast‐mediated bone mass increase.

Disclosures

All authors state that they have no conflicts of interest.

Acknowledgments

This work is part of the German Cushing’s Registry CUSTODES and has been supported by a grant from the Else Kröner‐Fresenius Stiftung to MR (2012_A103 and 2015_A228). Additionally, AR, FB, and MR received funding by the Deutsche Forschungsgemeinschaft (CRC/TRR 205/1 “The Adrenal Gland”). Furthermore, funds for this project were provided by the Verein zur Förderung von Wissenschaft und Forschung an der Medizinischen Fakultät der Ludwig‐Maximilians‐Universität München eV to LB.

The data are stored on the following repository: https://figshare.com/ and will be made accessible after publication of the article.

Authors’ roles: LB served as the principal investigator in this work and was responsible for the study conception and design, the analysis and interpretation of the data, and the drafting of the manuscript. JF, SZ, AO, AR, GR and SB contributed to the collection and analysis of the data. MS, FB, MD, MB substantially contributed to the interpretation of the data and the drafting of the manuscript. RS contributed to the conceptual design of the study, the interpretation of data and the revision of the paper. MR contributed to the conceptual design of the study, the collection, analysis and interpretation of data, and the drafting and revision of the paper. All authors contributed to the critical revision of the manuscript and approved the final version for publication.

From https://asbmr.onlinelibrary.wiley.com/doi/full/10.1002/jbmr.4033

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