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Study on the Safety and Effects of PBF-999 for Patients with Prader-Willi Syndrome

Verified siteInvestigationalNo placebo
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What is this trial about?

A plain-language summary of the goals, design and what participants do

This clinical trial is focused on studying the effects of a new treatment for Prader-Willi Syndrome, a genetic disorder that affects many parts of the body and often leads to a constant feeling of hunger, among other symptoms. The treatment being tested is a medication called PBF-999, which is taken in capsule form. The purpose of the study is to evaluate the safety and tolerability of PBF-999 in patients with Prader-Willi Syndrome over a period of 28 days.

Participants in the study will receive either the PBF-999 capsules or a placebo, which looks like the medication but does not contain the active ingredient. The study will monitor how the body processes the medication and any side effects that may occur. Throughout the study, participants will be asked to complete questionnaires and undergo various assessments to help researchers understand the impact of the treatment on their condition.

The study aims to gather important information about the potential benefits and risks of PBF-999 for individuals with Prader-Willi Syndrome. This research could lead to new insights and possibly new treatment options for managing the symptoms of this condition. Participants will be closely monitored by healthcare professionals to ensure their safety and well-being during the trial.

The research process

The trial runs in 5 steps – from screening to follow-up. Each step says what happens and what the team monitors.

  1. Step 1

    Initial visit

    Upon joining the study, you will attend an initial visit. During this visit, your eligibility will be confirmed based on specific criteria, such as age, diagnosis of Prader-Willi Syndrome, and other health factors.

    A healthcare professional will conduct a physical examination and collect necessary health information. You will also be required to provide a blood sample for genetic confirmation using a DNA methylation test.

  2. Step 2

    Consent and preparation

    You will be asked to provide informed consent, indicating your willingness to participate in the study. If you are under 18, your parent or guardian will need to provide consent on your behalf.

    A reliable caregiver, who has been caring for you for at least six months, must also provide consent to participate in the study.

  3. Step 3

    Treatment phase

    You will begin taking the study medication, PBF-999, in capsule form. The medication is taken orally once a day for a duration of 28 days.

    You will be monitored for any side effects or changes in your condition. Regular check-ins with the study team will be scheduled to ensure your safety and to assess the medication's effects.

  4. Step 4

    Follow-up visits

    Throughout the 28-day treatment period, you will attend follow-up visits. These visits are designed to monitor your health and the medication's impact.

    During these visits, you may be asked to complete questionnaires about your health and well-being, such as the HQ-CT and CGIC questionnaires.

  5. Step 5

    End of treatment evaluation

    At the end of the 28-day treatment period, a final evaluation will be conducted. This will include a physical examination and possibly additional blood tests to assess the medication's effects.

    The study team will review any treatment-emergent adverse events and collect data on physical and biological markers.

Who can join the trial?

7 criteria

  • Both males and females can participate.
  • Participants must be between 12 and 65 years old.
  • Participants must have a confirmed diagnosis of Prader-Willi Syndrome through a genetic test called a DNA methylation test.
  • For adults, the Body Mass Index (BMI) should be up to 65 kg/m2. BMI is a measure of body fat based on height and weight.
  • For adults, there should be no significant weight change (more than 10% of their starting weight) in the last 3 months before the first visit.
  • Participants must give their agreement to join the study and have a reliable caregiver who has been caring for them for at least 6 months. This caregiver must also agree in writing to participate. For children, a parent's consent is also needed.
  • Women who can become pregnant must have a negative pregnancy test. All women who can become pregnant, sexually active male participants, and their partners must agree to use effective birth control methods.

Who cannot join the trial?

5 criteria

  • Patients who do not have Prader-Willi Syndrome cannot participate.
  • Patients who are not within the specified age range cannot participate.
  • Patients who are not part of the specified clinical trial groups cannot participate.
  • Patients who are not male or female cannot participate.
  • Patients who are not considered part of a vulnerable population cannot participate.
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Investigated drugs

PBF-999 is a medication being studied for its potential to help people with Prader-Willi Syndrome, a condition that affects many parts of the body and can cause a constant feeling of hunger. This medication is being tested to see if it is safe and well-tolerated by patients over a period of 28 days. The goal is to understand how the body processes the medication and to see if it can help manage symptoms of the syndrome.

What is already known about the treatment

PBF-999 – PBF-999 is administered orally in the form of a tablet, making it easy for patients to take. It is currently being studied in clinical trials, specifically in a Phase 2 study, to assess its effectiveness and safety for treating Prader-Willi Syndrome, a genetic disorder. The main goal of this medication is to improve symptoms associated with Prader-Willi Syndrome by targeting specific pathways in the body, although the exact molecular mechanism is still under investigation. PBF-999 is classified as an investigational drug, meaning it is not yet approved for general medical use and is being evaluated for its potential benefits and risks.

Investigated diseases

Prader-Willi Syndrome – Prader-Willi Syndrome is a genetic disorder that affects multiple parts of the body. It is characterized by weak muscle tone, feeding difficulties, poor growth, and delayed development in infancy. As children grow, they often develop an insatiable appetite, which can lead to chronic overeating and obesity. Individuals with this syndrome may also experience intellectual impairment, learning disabilities, and behavioral problems. Hormonal deficiencies, particularly in growth and sex hormones, are common. The syndrome is caused by the loss of function of specific genes on chromosome 15.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IITrial ID2022-501462-22-00Protocol codePBF-999CT-04Estimated enrolment40 patientsSponsorPalo Biofarma S.L.

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On this site, “treatment” means an investigational medicine being studied in a clinical trial. Its safety and efficacy for the use being studied have not yet been confirmed, some participants may receive a placebo or a comparator medicine, and taking part does not guarantee any health benefit. The decision to take part is made by the doctor at the research site. This site is for information only and does not replace medical advice.

This service is not affiliated with the European Commission, the EMA, or the official CTIS system. Most information comes from publicly available international clinical-trial registries, supplemented by data from academic sites, national regulators and commercial sponsors. On this site, “treatment” and “therapy” mean a medicine being tested in a clinical trial. Its safety and effectiveness in the use being studied are not yet confirmed, some participants may receive a placebo or a comparator, and taking part does not guarantee a health benefit. The doctor at the research site decides who can take part. This site provides information, not medical advice. Certain content and visual elements on this website have been generated or enhanced using artificial intelligence (AI).