Behavioral changes in patients with Prader-Willi syndrome receiving diazoxide choline extended-release tablets compared to the PATH for PWS natural history study

BACKGROUND

Prader-Willi syndrome (PWS) is a rare neurobehavioral-metabolic disease caused by the lack of paternally expressed genes in the chromosome 15q11-q13 region, characterized by hypotonia, neurocognitive problems, behavioral difficulties, endocrinopathies, and hyperphagia resulting in severe obesity if energy intake is not controlled. Diazoxide choline extended-release (DCCR) tablets have previously been evaluated for their effects on hyperphagia and other behavioral complications of people with PWS in a Phase 3 placebo-controlled study of participants with PWS, age 4 and older with hyperphagia (C601) and in an open label extension study, C602.

METHODS

To better understand the longer-term impact of DCCR, a cohort from PATH for PWS, a natural history study that enrolled participants with PWS age 5 and older, who met the C601 age, weight and baseline hyperphagia inclusion criteria and had 2 hyperphagia assessments ≥ 6 months apart, were compared to the C601/C602 cohort. Hyperphagia was measured using the Hyperphagia Questionnaire for Clinical Trials (HQ-CT, range 0-36). The primary analysis used observed values with no explicit imputation of missing data. A sensitivity analysis was conducted in which all missing HQ-CT assessments in the C601/C602 cohort were assigned the highest possible value (36), representing the worst-case scenario. Other behavioral changes were assessed using the Prader-Willi Syndrome Profile questionnaire (PWSP).

RESULTS

Relative to the PATH for PWS natural history study cohort, the DCCR-treated C601/C602 cohort showed significant improvements in HQ-CT score at 26 weeks (LSmean [SE] -8.3 [0.75] vs. -2.5 [0.43], p < 0.001) and 52 weeks (LSmean [SE] -9.2 [0.77] vs. -3.4 [0.47], p < 0.001). The comparison between the cohorts remained significant in the worst-case imputation sensitivity analysis. There were also significant improvements in all domains of the PWSP at 26 weeks (all p < 0.001) and 52 weeks (all p ≤ 0.003) for C601/C602 participants compared to the PATH for PWS participants.

CONCLUSION

Long-term administration of DCCR to people with PWS resulted in changes in hyperphagia and other behavioral complications of PWS that are distinct from the natural history of the syndrome as exemplified by the cohort from PATH for PWS. The combined effects of administration of DCCR should reduce the burden of the syndrome on the patient, caregivers and their families, and thereby may benefit people with PWS and their families.

TRIAL REGISTRATION

Clinical study C601 was originally registered on ClinicalTrials.gov on February 22, 2018 (NCT03440814). Clinical study C602 was originally registered on ClinicalTrials.gov on October 22, 2018 (NCT03714373). PATH for PWS was originally registered on ClinicalTrials.gov on October 24, 2018 (NCT03718416).

Neuropsychiatric features of Prader-Willi syndrome

Prader-Willi syndrome (PWS) is a genetic disorder characterized by hypotonia and poor feeding in infancy which progresses to hyperphagia in early-mid childhood, as well as developmental delays, a spectrum of behavioral and psychiatric concerns, endocrinopathies, orthopedic issues, and less commonly, seizures, sleep apnea, and narcolepsy with or without cataplexy. This study used data in the Global PWS Registry (N = 893) to explore the onset and severity over time of the neuropsychiatric features reported in individuals with PWS and explored its associations with sleep disorders, seizures, and psychiatric symptoms. Results demonstrate that seizures are more common in the deletion subtype and that narcolepsy and cataplexy are more common in individuals who have sleep-related seizures. Finally, this work shows that anxiety and compulsive behaviors are persistent features of PWS that may arise early in childhood, and that anxiety is associated with higher frequency of other comorbid psychiatric diagnoses. In conclusion, this study is one of the largest to date characterizing sleep disorders and neuropsychiatric characteristics of individuals with PWS and reports on the novel association between sleep disorders and seizures. This study is also one of the first to offer details on the nature of the progression of these features in individuals with PWS.

Suicidality in individuals with Prader-Willi syndrome: a review of registry survey data

INTRODUCTION

Prader-Willi syndrome (PWS) is a rare, genetic, neurodevelopmental syndrome associated with hyperphagia and early onset obesity, growth and sex hormone insufficiencies, mild-to-moderate intellectual disability, and behavioral challenges such as compulsivity, anxiety, skin picking, social skills deficits and temper outbursts. Given high rates of psychiatric comorbidity and potential risk factors for suicide in PWS, this study sought a first estimate of the prevalence of suicidal ideation (SI) and attempts (SA) in the PWS population and any characteristics associated with suicidality in this population.

METHODS

Using the Global Prader-Willi Syndrome Registry, we included all participants who had answered a question about SI. We examined the most recent data from the surveys about social, economic, and demographic factors, genetic subtype, and psychiatric symptoms and treatments. A chi-square analysis was used to compare registry participants who reported SI to those without reported SI.

RESULTS

From 750 included survey respondents, 94 (12.5%) endorsed some history of SI. Of these, 25 (26.6%) also reported a history of SA, with an average age of 16.25 years at their first attempt. Those with a history of SI were predominantly male and adult age, and had higher rates of aggression and psychiatric comorbidities, therapies, and medications.

CONCLUSIONS

This study indicates that the rate of SI and SA in PWS is comparable to the general population, and that suicide attempts in PWS typically begin in middle-teenage years. Despite unique challenges, individuals with PWS and their caregivers should be included in screens and psychoeducation for suicide and mental health concerns.

Characteristics and relationship between hyperphagia, anxiety, behavioral challenges and caregiver burden in Prader-Willi syndrome

Objectives

Prader-Willi syndrome (PWS) is a rare genetic disorder characterized by maladaptive behaviors, amongst which hyperphagia is a life-long concern for individuals with PWS and their caregivers. The current study examined the contribution of hyperphagia and other factors to caregiver burden across lifespan, in 204 caregivers of individuals with PWS living in the US, using the Zarit Burden Interview (ZBI) and the hyperphagia questionnaire (HQ-CT).

Results

We found a strong relationship between ZBI and HQ-CT especially in individuals with PWS older than 4 y and showed that HQ-CT scores of individuals with PWS is positively correlated with ZBI scores of their caregivers. The weight status of individuals with PWS was not associated with HQ-CT and ZBI scores, except for obese individuals who had significantly higher HQ-CT scores when compared to normal weight PWS individuals. We looked at PWS symptoms and care-related issues that impacted individuals and caregivers the most. We found that care-related tasks had the biggest negative impact on caregivers of children aged 0–4 y, whereas anxiety, temper tantrums, and oppositional behaviors of older individuals with PWS had the biggest impact on their caregivers concomitant with their high caregiver burden. Finally, we assessed the variability of HQ-CT and ZBI over 6 months in a subgroup of 83 participants. Overall, neither measure differed between 6 months and baseline. Most individual’s absolute HQ-CT score changes were between 0–2 units, whereas absolute ZBI score changes were between 0–6 points. Changes in the caregiver’s or individual’s life had little or no effect on HQ-CT and ZBI scores.

Conclusions

This study demonstrates a relationship between hyperphagia and caregiver burden and sheds light on predominant symptoms in children and adolescents that likely underly PWS caregiver burden. The stability and relationship between HQ-CT and ZBI support ZBI as an additional outcome measure in PWS clinical trials.

Variability and change over time of weight and BMI among adolescents and adults with Prader-Willi syndrome: a 6-month text-based observational study

BACKGROUND

Prader-Willi syndrome (PWS) is a rare neurodevelopmental disorder in which hyperphagia (excessive appetite) is a hallmark feature. Understanding how weight changes over time in this population is important for capturing the contemporary natural history of the disorder as well as assessing the impact of new treatments for hyperphagia. Therefore, we aimed to determine the feasibility of a remote assessment of weight change over time in PWS.

METHODS

We developed a text message-based, prospective cohort study of adolescents and adults with PWS to assess changes in weight and body mass index (BMI) over a six-month period. Weight was collected weekly, while changes in height, living situation, access to food, activity level, and medication were collected at three-month intervals.

RESULTS

One hundred and sixty-five participants enrolled in the study, with a mean age of 19.7 years (range 12-48). There was considerable variability in weight across participants (range: 76.8-207.7 kg). Thirty-three percent of the participants were normal weight, while 15% were overweight and 52% were obese. Overall, the weight of the study participants increased over the study period (mean weight change + 2.35%), while BMI was relatively stable, albeit high (mean BMI of 31.4 at baseline, mean BMI percent change + 1.42%). Changes in living situation, activity, food access, and medication had limited impact on weight and BMI changes. Multivariable analysis found that time, sex, age, and percentage of life on growth hormone (GH) therapy were statistically significant fixed effects. Participants submitted more than 95% of possible weight data points across the 26 weeks of the study.

CONCLUSIONS

This remote, observational study of weight change in PWS showed small increases in weight and BMI over a six-month period. Participants were highly compliant with this text message-based study, suggesting that mobile technology-based data collection was manageable for the participants. We anticipate that the results of this study will inform clinical trials for hyperphagia/obesity related therapies in PWS and provide a basis for understanding the efficacy of new therapies for hyperphagia in the real-world setting.

The Global Prader-Willi Syndrome Registry: Development, Launch, and Early Demographics

Advances in technologies offer new opportunities to collect and integrate data from a broad range of sources to advance the understanding of rare diseases and support the development of new treatments. Prader–Willi syndrome (PWS) is a rare, complex neurodevelopmental disorder, which has a variable and incompletely understood natural history. PWS is characterized by early failure to thrive, followed by the onset of excessive appetite (hyperphagia). Additional characteristics include multiple endocrine abnormalities, hypotonia, hypogonadism, sleep disturbances, a challenging neurobehavioral phenotype, and cognitive disability. The Foundation for Prader–Willi Research’s Global PWS Registry is one of more than twenty-five registries developed to date through the National Organization of Rare Disorders (NORD) IAMRARE Registry Program. The Registry consists of surveys covering general medical history, system-specific clinical complications, diet, medication and supplement use, as well as behavior, mental health, and social information. Information is primarily parent/caregiver entered. The platform is flexible and allows addition of new surveys, including updatable and longitudinal surveys. Launched in 2015, the PWS Registry has enrolled 1696 participants from 37 countries, with 23,550 surveys completed. This resource can improve the understanding of PWS natural history and support medical product development for PWS.

Prader-Willi syndrome mental health research strategy workshop proceedings: the state of the science and future directions

Abstract

This paper reports on the ‘Prader-Willi Syndrome (PWS) Mental Health Research Strategy Workshop’ that took place in March 2015. PWS is characterized by a complex phenotype affecting multiple systems with a high prevalence of maladaptive behaviours, and neuropsychiatric illness. Prader Willi syndrome results from the absence of paternally derived alleles located at the imprinted chromosomal locus, 15q11–13. The goal of the workshop was to highlight the state of the science of the mental health of people with this rare neurodevelopmental disorder. Mental ill health and maladaptive behaviors significantly impact quality of life for persons with PWS and their caregivers. Effective treatments and further research into this area are critically needed.

Methods

A multidisciplinary group of scientists and health care professionals were brought together to discuss the mental health and behavioral needs of people with PWS. The workshop strategy was to integrate established work on PWS with other relevant areas of study. The meeting also focused on two neurobiological systems that research had suggested were relevant to understanding the broader mental health aspects of PWS: the autonomic nervous system and oxytocin/vasopressin pathways. Other relevant topics were considered and recommendations made.

Results

The workshop presentations and working group discussions revealed that no one approach was sufficient to fully conceptualize the mental health challenges in PWS. Workshop discussions pointed to the need for theoretically informed studies focused on clinical characterization, measurement, and the probing of specific neurobiological systems through pharmaceutical or other interventions. Future studies in this area should explore the use of advanced neuroimaging protocols, as well as molecular studies using iPS cells in order to create more informed theories.

Conclusions

Within this framework, workshop participants identified and prioritized key research questions, and highlighted current opportunities. Recommendations were made with respect to the development of specific resources and tools for furthering mental health research such as The Global PWS Registry, the development of effective endpoints, the use of animal models and iPS cells to aid understanding of the neurobiological underpinnings. Additionally, collaborative opportunities across disciplines and syndromes were highlighted and targeted research initiatives focused on psychological/behavioral interventions modified for use in PWS were recommended.

Abstract 348: Extracellular heat shock protein 90 (eHsp90) initiates EMT events and enhances cell motility in prostate cancer

Prostate Cancer (PCa) is the most commonly diagnosed malignancy in men, responsible for the second highest lethality. Although early cancer detection and treatment is often curative, subsequent metastatic spread of tumor cells renders the disease incurable. Activation of the epithelial to mesenchymal transition (EMT) genetic program is considered a key event contributing to metastatic potential and subsequent lethality. Although targeting EMT may be a promising approach for improving treatment outcome, the main, potentially druggable, targets driving this pathway in PCa remain poorly defined. Multiple reports indicate that extracellular Hsp90 (eHsp90) promotes cell motility, invasion, and metastasis in a number of cancer cell types. Intriguingly, eHsp90 has been preferentially detected in the serum or plasma from aggressive cancers. Its presence in the serum of metastatic PCa patients implicates a potential causative role in PCa. Therefore, our objective was to investigate whether eHsp90 may influence EMT events, thereby influencing the metastatic potential of PCa. We now report that paired sets of differentially aggressive PCa tumor cell lines exhibited higher expression of eHsp90. Functionally, exposure of PCa cells to eHsp90 elicted a significant increase in cell motility. Inversely, blockade of eHsp90 attenuated the activation of several pro-motility effectors, concomitant with the significant suppression of cell migration. These events were associated with a profound alteration of cellular morphology towards a mesenchymal phenotype. Changes in cell phenotype were coupled with a loss and redistribution of the EMT suppressive gatekeeper protein E-cadherin. eHsp90 was also found to impact on the localization of other junctional proteins known to maintain a cuboidal epithelial phenotype. Finally, eHsp90 was found to transcriptionally upregulate several of the established transcriptional factors known to initiate EMT events. Confirmation of the EMT inducing ability of eHsp90 was determined by focused quantitative real time EMT PCR arrays. Our results therefore highlight a novel role for eHsp90 as a central regulator of EMT events in PCa. Our findings further support the premise that therapeutic targeting of eHsp90 may have the potential to suppress EMT activation and diminish the dissemination and metastatic propensity of PCa tumor cells.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 348. doi:1538-7445.AM2012-348

Abstract 545: Heat Shock Protein 90 (eHsp90): A novel modulator of the tumor microenvironment and cancer progression

Prostate Cancer (PCa) is one of the most lethal diseases afflicting men. Although early cancer detection and treatment is often curative, subsequent metastatic spread of tumor cells renders the disease untreatable. Treatment failure is also due to a poor understanding of the contribution of the tumor microenvironment to disease progression. We find that a number of PCa cells secrete heat shock protein 90 (Hsp90). Extracellular Hsp90 (eHsp90) acts in a manner distinct from the intracellular chaperone and possesses ‘chaperokine’ properties. The ability of chaperones to buffer against cellular stress and promote survival of malignant cells led us investigate the potential role of eHsp90 in PCa progression. Interestingly, we find that eHsp90 expression correlates with PCa aggressiveness. Consistently, the more aggressive and metastatic PCa cells exhibit several fold higher eHsp90 secretion relative to their weakly tumorigenic matched counterparts. Interference with this pathway by antibody or drug-mediated neutralization dramatically impaired tumor cell migration. Concomitant with inhibition of eHsp90, the activation of several critical downstream signaling mediators of cell motility were attenuated. The multifunctional receptor LRP-1 (LDL-receptor Related protein-1) has been proposed as the receptor for eHsp90. The silencing of LRP1 dramatically suppressed PCa signaling and cell migration. The ability of LRP1 knockdown to recapitulate the drug dependent inhibition of eHsp90 strongly supports the requirement for an Hsp90-LRP1 signaling axis in PCa progression. A major component of the solid tumor microenvironment is the stromal fibroblast, which acts to potentiate both tumor growth and metastatic spread. Addition of Hsp90 to prostate stromal fibroblasts, which do not secrete Hsp90 protein, potently stimulates ERK activation and cell motility, demonstrating that the eHsp90 chaperokine possess paracrine effects upon the tumor stroma and induces properties associated with a reactive phenotype. The ability of eHsp90 to induce both ERK activation and cell motility was inhibited by an MMP inhibitor, suggesting that eHsp90 dependent modulation of MMP activity is a requirement for its downstream effects on stromal signaling and cell motility. Our data implicate that eHsp90 secretion may represent a critical component of PCa aggressiveness via its ability to initiate multiple signaling events in stromal fibroblasts that enable these cell to further drive tumor growth. Our studies raise the possibility that approaches designed to curtail eHsp90 activity may be a useful strategy to intercept tumor-stromal dynamic signaling, which is predicted to have a favorable impact upon the progression of prostate cancer.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 545.

Effects of polybrominated diphenyl ethers on basal and TCDD-induced ethoxyresorufin activity and cytochrome P450-1A1 expression in MCF-7, HepG2, and H4IIE cells

Polybrominated diphenylethers (PBDEs) are used as additive flame-retardants in consumer products to reduce the chances of ignition and burning. Levels of certain PBDE congeners have been increasing in fish, wildlife, and human tissues during the last decades. Some PBDEs are lipophilic and persistent, resulting in bioaccumulation in the environment. The structural similarity of PBDEs to other polyhalogenated aromatic hydrocarbons such as PCBs, has raised concerns that PBDEs might act as agonists for the aryl hydrocarbon receptor (AhR). To study the possible AhR-mediated effects of the environmentally relevant PBDEs (BDE47, 77, 99, 100, 153, 154, 183, 209), the induction of cytochrome P450-1A1 (CYP1A1) was studied in human breast carcinoma (MCF-7), human hepatocellular carcinoma (HepG2), and rat hepatoma (H4IIE) cells. 7-Ethoxyresorufin-O-deethylase (EROD) was used as a marker for CYP1A1 activity. Cells were exposed for 72 h to various PBDE concentrations (0.01-10 microM). Positive controls were 2,3,7,8-TCDD (0.001-2.5 nM) and PCB126 (0.01-10 nM). None of these PBDEs was capable of inducing EROD activity; this was confirmed by real time RT-PCR for CYP1A1 mRNA. However, in cells exposed to PBDEs in combination with TCDD, a concentration-dependent decrease in TCDD-induced EROD activity occurred. Co-exposure of BDE153 (10 muM) and a maximally inducing concentration of TCDD (1 nM) reduced EROD activity to 49% of the maximum induction by TCDD alone. All tested PBDEs showed similar effects in each cell line, though quantitative differences were observed. The observed decrease in CYP1A1 activity was not due to PBDE-dependent catalytic inhibition of EROD activity or cytotoxicity, nor were decreased CYP1A1 mRNA levels observed. However, inhibition of luciferase induction in mouse (Hepa) and rat (H4IIE) hepatoma cells containing a stably transfected AhR-responsive luciferase reporter gene, suggests that BDE77 is a weak AhR antagonist or partial agonist.