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Biomarkers and Beyond: 2016 Update from PWS Clinical Trials Consortium

Learn what the PWS Clinical Trials Consortium did in 2016 to promote FDA approval for PWS treatments by addressing key challenges of PWS clinical trials.


biomarkers-and-beyond-2016-update-from-pws-clinical-trials-consortium.jpgOver the past several years, the PWS community has been fortunate to see several potential therapies for PWS enter clinical trials. To date, the only FDA-approved drug for the treatment of PWS is growth hormone, but it's clear that new medications are needed to help those with PWS manage the insatiable hunger and behavioral challenges. Given the current pipeline, we are hopeful that over the next few years we will see therapies successfully break through and get FDA approval for PWS.

The PWS Clinical Trials Consortium is contributing to achieving that goal by addressing the key challenges of PWS clinical trials. This blog gives an overview of the Consortium's activities in 2016.

Addressing the Challenges Facing PWS Clinical Trials

In the last decade, researchers have made remarkable progress in the PWS research field, and our community has developed a number of resources, such as the PWS Registry, that have led to clinical trials for PWS that are currently going. Several key challenges, however, remain to be resolved to ensure the success of upcoming and longer-term trials for PWS. These include:

  • understanding the natural history of PWS,
  • developing new meaningful trial endpoints, and
  • developing a structured approach to incorporate the patient's and caregiver`s voices in the regulatory decision-making.

Addressing unmet scientific, technical, clinical, and regulatory needs for clinical trials for PWS is a tough job, requiring expertise, capabilities, and resources from multiple disciplines and stakeholders. The PWS Clinical Trials Consortium includes stakeholders from pharmaceutical industries, academia, and patient organizations that bring a wealth of information and experience to the table as we work to eliminate the challenges of clinical trials and facilitate the development and approval of safe and effective therapies for PWS.

2016 Consortium Focus

Created in 2015, the Consortium is working to address the key challenges of PWS clinical trials. Over the past year, we have focused on the following:


A survey was developed and shared to assess the availability of PWS biological materials and the level of information associated with the materials. Why is this important? Knowing what samples are available internationally will help the development of biomarkers that can predict the patient`s response to candidate drugs in a clinical trial. The survey was an important first step in assessing the quantity and quality of available biological samples for PWS.

Nutritional Phases

Dr. Miller and Dr. Driscoll have described six nutritional phases of PWS, and the Consortium is working to develop guidelines that help clinicians classify patients with PWS according to these nutritional phases. Why is this important? If clinicians can accurately identify a patient’s nutritional phase, they can determine if/when a patient will progress to the next phase. The nutritional classification could be a tool to determine if a candidate drug has halted the progression to hyperphagia.

Behavioral Biomarkers

The Dykens Hyperphagia Questionnaire is currently the most widely used tool to measure efficacy of drugs against hyperphagia in clinical trials, however, it does not capture the range of behaviors clinicians and caregivers feel should be captured. In 2016, a group composed of caregivers and clinicians came together to analyze tools that have been used in PWS and other disorders to measure food-related and non-food-related behaviors across ages.

The group is now developing a new questionnaire to capture strategies caregivers are using to control the food environment that could complement the questionnaire and provide more information on patients who are hyperphagic but whose weight is under control. Why is this important? If behaviors such as hyperphagia and anxiety can be better measured, we can more accurately evaluate the efficacy of a given drug.

Incorporating Patient and Caregiver Perspectives

Several projects have been launched with the aim of incorporating patient and caregiver perspectives in the clinical trial process. Why is this important? See below:

  1. Dr. John Bridges at John Hopkins is using patient preference methods to incorporate a caregiver's perspective on the benefits and risks they are willing to take with regard to treatment options for their children with PWS. This is a two-year project that will be published and act as a guide for the FDA as they make regulatory decisions on drug approval for PWS.

  2. A filmmaker has recorded the necessary footage to produce a video that will illustrate to external constituencies, such as the FDA, the burden associated with PWS symptoms on patient and caregiver quality of life. We expect video production to wrap up mid-2017.

  3. A survey to measure the caregiver burden in PWS was shared with the PWS community, and the responses have been analyzed. We found that caregivers of those with PWS display a high level of burden compared to caregivers for those with other diseases. The information that has come out of the survey and its analysis will be published in a scientific journal mid-2017.

The important work of the PWS Clinical Trials Consortium is made possible only by the many stakeholders who are providing their time, talent, and treasure to the program. The combined expertise of industry, academia, and caregivers will allow us to overcome challenges that no single group could achieve in isolation.

The 2016 members of the Consortium include: Zafge; Rhythm Pharmaceuticals; Alize Pharma; Essentialis (now Capnia); FPWR; FPWR-Canada; PWSA-USA; IPWSO; Association Prader-Willi France; and respected members of the PWS academic research community including Drs. Dimitropoulos, Höybye, Miller, Roof, Roth, Scheimann, Dimitropoulos, Salehi, Duis, Tauber, and others.

For updated information on PWS clinical trial opportunities and to sign up for a monthly PWS Clinical Trial Alert, visit the PWS Clinical Trials page.PWS Clinical Trials

Topics: Research

Nathalie Kayadjanian


Nathalie Kayadjanian, Ph.D is an expert in translational biomedical research. A neuroscientist by training, she has extensive R&D experience in academia, biotech, and the pharmaceutical industry in Europe and the USA. Nathalie has occupied top management positions in patient-driven non-profit organizations, developing and implementing strategies to accelerate the development of innovative therapies for rare diseases.