PWS Clinical Trials Overview [VIDEO]

This blog provides a brief summary of the PWS Clinical Trials Overview presentation given by research team member Theresa Strong. You can watch the full presentation by clicking on the embedded video below.

In case you don't have time to watch the full video, we've captured some of the key points in the notes below.

Theresa Strong is a geneticist and founding member of FPWR. She serves as our Director of Research Programs and is the lead investigator on the Global PWS Registry.

Steps in the Drug Development Process

The steps in the drug development process include:

  • Drug discovery
  • Pre-clinical: to determine if the drug works in animals, has the effect that researchers want and is safe
  • Clinical trials in humans: take place over three phases with increasing numbers of participants
  • Food and Drug Administration (FDA) review
  • FDA approval
  • Post-marketing surveillance: involves a continuing review of safety data after the drug goes to market

It can take up to 15 years and cost up to one billion dollars to bring a drug to market.

Orphan Drug Development

As a rare disease, drugs being developed for PWS fall under the FDA’s Office of Orphan Products Development (OOPD), which was established in 1983 to encourage development of drugs for rare diseases and disorders. The FDA’s definition of a “rare disease” is one that impacts fewer than 200,000 people in the U.S. An estimated 20,000 individuals have been diagnosed with PWS, putting us well within the requirements. The government encourages development of so-called “orphan” drugs by offering incentives such as market exclusivity, tax credits and accelerated approvals.

Benefit (for pharmaceutical companies) to work in our population:

  • Homogeneity: people with PWS have the same genetic issue that’s causing hyperphagia
  • Compelling unmet medical need
  • Potential for a less expensive route to approval
  • Motivated, active population - we want treatments!

Risks/challenges companies face in our population:

  • Limited patient population
  • Intellectual disability
  • Behavioral problems
  • High potential for drug interaction, particularly in adults who are already on multiple medications
  • More expensive on a per-patient basis

Phases of Clinical Trials

One thing to keep in mind is that the three phases of clinical trials are not always completely linear.

Phase 1: ‘First in Human’ Trial

  • Small trial (10 to 20 people for an orphan drug population)
  • Short in duration
  • Conducted to make sure there no unexpected safety issues
  • Determines how does the drug interacts with the human body

Phase 2

  • Slightly larger population (30 to 40 people for a rare disease)
  • Looks at different dosing
  • Conducted to look for a biological activity or effect

Phase 3: Pivotal

  • Larger studies (about 100 people for a rare disease)
  • Involve longer exposure to the drug
  • Researchers are looking for evidence that the drug is effective and better than what’s currently available

After the three phases, the FDA pulls and reviews data, conducts a benefit risk assessment and decides whether the drug can go to market. The patient perspective has become much more important to this process over time, and we’re looking for more ways to formalize patient feedback.  

Our Challenge & Becoming a ‘Research Ready’ Community

The number one reason for delays or disruptions to the drug development process is a lack of participants in clinical trials. Which is why it’s so important for parents to at least gather information about the trials to make a decision about whether to participate.  

Becoming a “research ready community entails:

  • Robust diagnostic test
  • Understanding the biology of the disorder
  • How it progresses over time
  • Patient registry
  • Families have an idea of what the current clinical trials are
  • Defined unmet medical need

Two current studies to understand drug development involve caregiver burden and treatment preferences. Parents should look at the criteria for each study to see if they’re eligible.

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

Theresa Strong


Theresa V. Strong, Ph.D., received a B.S. from Rutgers University and a Ph.D. in Medical Genetics from the University of Alabama at Birmingham (UAB). After postdoctoral studies with Dr. Francis Collins at the University of Michigan, she joined the UAB faculty, leading a research lab focused on gene therapy for cancer and directing UAB’s Vector Production Facility. Theresa is one of the founding members of FPWR and has directed FPWR’s grant program since its inception. In 2016, she transitioned to a full-time position as Director of Research Programs at FPWR. She remains an Adjunct Professor in the Department of Genetics at UAB. She and her husband Jim have four children, including a son with PWS.