Patients & Families

Livoletide Pivotal Study (ZEPHYR)

The team at Millendo is working hard to develop a medication that may help reduce the constant hunger and food-related behaviors associated with Prader-Willi syndrome (PWS). We are currently conducting a human clinical study of Millendo‚Äôs lead candidate, livoletide, in patients with PWS.  Livoletide is an investigational drug that has not yet been approved for use by a regulatory authority.

The ZEPHYR clinical research study includes participants 8 to 65 years of age with a PWS diagnosis, and who have a single primary caregiver.

This study will test the effectiveness, safety, and tolerability of livoletide in reducing hyperphagia (insatiable hunger) and other food-related behaviors in people with PWS.

For more information about the ZEPHYR clinical study, please visit

What is the ZEPHYR study?

The ZEPHYR study is a clinical research study of livoletide for people with Prader-Willi syndrome (PWS). The study is designed to answer the following questions:

  • What are the effects of livoletide on hyperphagia (insatiable hunger) and food-related behaviors in people with PWS?
  • What are the effects of livoletide on body weight, waist circumference, and fat mass?
  • How safe and well-tolerated is livoletide?

What is livoletide?

Livoletide is an investigational drug being studied by Millendo Therapeutics for the treatment of patients with Prader-Willi syndrome. Livoletide has not yet been approved for use by a regulatory authority.

How is livoletide designed to work?

Based on previous research in laboratory and animal experiments, livoletide may improve hyperphagia and other metabolic effects, such as obesity and high blood glucose, by potentially counteracting a hormone in the body called Acylated Ghrelin (AG). Acylated Ghrelin (AG) stimulates appetite and is associated with other metabolic effects.

Has livoletide been administered yet to people?

Yes. More than 150 healthy volunteers and people with obesity, Type 2 diabetes, and PWS have been given livoletide in other clinical research studies. Overall, livoletide appears to be well-tolerated. In a Phase 2 study of livoletide in 47 patients with PWS, safety events in patients treated with livoletide were similar to those in the placebo group (subjects reporting any adverse events (AEs): livoletide 60.9% vs. Placebo 58.3%). Most commonly reported AEs in both groups were related to irritation at the injection site (livoletide was administered as a once or twice daily subcutaneous injection), with no serious AEs reported and no discontinuations due to AEs.