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Study of alpelisib in children and adults with PIK3CA-Related Overgrowth Spectrum (PROS)

Fast replyInvestigationalNo placebo
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What is this trial about?

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

This study focuses on PIK3CA-Related Overgrowth Spectrum (PROS), a condition that causes abnormal tissue growth in various parts of the body. The research examines the effectiveness and safety of a medication called alpelisib (also known as BYL719) in both children and adults with this condition. The medication comes in the form of film-coated tablets and granules that are taken by mouth.

The purpose of this study is to determine if alpelisib can help reduce the size of tissue overgrowth in people with PROS. During the study, participants will receive either alpelisib or placebo. The medication will be given daily for 16 weeks, with the possibility of continued treatment. The study will measure changes in the size of affected tissue areas using Magnetic Resonance Imaging (MRI) scans.

The treatment will be evaluated based on whether it can reduce the size of abnormal tissue growths by at least 20%. Participants will be monitored throughout the study to check how well the medication works and to watch for any side effects. The study includes both adults aged 18 and older, and children between 6 and 17 years old.

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 screening

    Your doctor will perform screening procedures to confirm your eligibility for the study

    A test will be performed to check for PIK3CA gene mutation in your tissue sample

    Medical tests will check your blood sugar levels: fasting glucose must be ≤140 mg/dL and HbA1c (long-term blood sugar measure) must be ≤6.5%

  2. Step 2

    Baseline measurements

    An MRI scan will be taken to measure your lesions - at least one lesion must be 2 cm or larger

    Your lesions will be assessed by independent medical experts

    Your general physical condition will be evaluated using a performance status score

  3. Step 3

    Treatment period - first 16 weeks

    You will be randomly assigned to receive either alpelisib (BYL719) tablets or placebo tablets

    The medication or placebo will be taken by mouth daily

    The tablets come in two strengths: 50 mg (light yellow) and 125 mg (dark yellow)

  4. Step 4

    Monitoring and assessment

    Your lesions will be measured regularly using MRI scans

    Success of the treatment will be determined by at least 20% reduction in lesion size

    Your lesions will be monitored to ensure none have grown by 20% or more

    You will be checked for any new lesions that may develop

  5. Step 5

    Long-term follow-up

    The study will continue until June 2030

    Regular assessments will monitor your response to treatment

    Your overall health and any side effects will be tracked throughout the study period

Who can join the trial?

14 criteria

  • You must sign an informed consent form before any study procedures begin. For minors, parent or legal guardian consent is required
  • You must have PROS (PIK3CA-Related Overgrowth Spectrum) with symptoms that are getting worse and at least one measurable growth that can be evaluated by medical experts
  • You must have documented evidence of changes in the PIK3CA gene confirmed by laboratory tests
  • You need to provide a tissue sample for testing. This can be either:
    • An existing (archival) tissue sample, or
    • A new tissue sample (if required and medically safe to obtain)
    • You must have adequate physical functioning ability as measured by:
      • Karnofsky score (for patients over 16 years) or
      • Lansky score (for patients 16 years or younger)
      • The score must be 50 or higher
      • Your blood tests must show:
        • Fasting blood sugar level of 140 mg/dL or less
        • HbA1c (average blood sugar) level of 6.5% or less
        • Adequate bone marrow and organ function
        • You must have at least one PROS-related growth that:
          • Is at least 2 centimeters in size
          • Can be measured accurately by MRI (magnetic resonance imaging)
          • Causes symptoms or limits your daily activities

Who cannot join the trial?

12 criteria

  • History of severe hypersensitivity (allergic reaction) to alpelisib or similar medications
  • Active malignant cancer (cancer that is growing or spreading) or history of cancer in the past 3 years, except for successfully treated skin cancers
  • Severe uncontrolled diabetes (blood sugar levels that are not well managed)
  • Pregnancy or breastfeeding for female participants
  • Participation in another clinical trial within 30 days before starting this study
  • Severe liver problems or abnormal liver function tests
  • Serious heart conditions, including:
    • Uncontrolled high blood pressure
    • Recent heart attack
    • Unstable heart rhythm problems
    • Severe mental health conditions that could interfere with following study procedures
    • Use of medications that could interact with the study drug
    • Any medical condition that the study doctor believes would make participation unsafe
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Investigated drugs

Alpelisib (also known as BYL719) is a medication that targets a specific genetic pathway involved in tissue growth. It is designed to treat a condition called PIK3CA-Related Overgrowth Spectrum (PROS), which causes certain parts of the body to grow disproportionately. This medication works by blocking abnormal cell growth signals in affected tissues, potentially helping to reduce or control overgrowth in patients with PROS. It is taken orally and is being studied in both adults and children over 6 years of age.

What is already known about the treatment

Alpelisib (BYL719) - An oral medication specifically designed to treat PIK3CA-Related Overgrowth Spectrum (PROS), which is administered in tablet form for both adult and pediatric patients. This targeted therapy works by inhibiting the PIK3CA enzyme, which is responsible for abnormal cell growth in PROS conditions. The medication belongs to the class of PI3K inhibitors and represents a significant advancement in treating genetic overgrowth disorders, having shown promising results in clinical trials for patients aged 6 years and older. Currently, it is being evaluated in Phase II clinical trials to establish its efficacy, safety, and pharmacokinetic profile in both pediatric and adult populations.

Investigated diseases

PIK3CA-Related Overgrowth Spectrum (PROS) - A rare genetic condition characterized by overgrowth of various tissues in the body due to mutations in the PIK3CA gene. The condition causes different parts of the body to grow disproportionately, leading to enlargement of affected tissues and organs. PROS can affect multiple areas including blood vessels, fat tissue, muscles, bones, and skin. The overgrowth typically begins during early development and continues throughout life, with symptoms varying widely among affected individuals. The condition may involve one or multiple body parts, and the extent of tissue overgrowth can range from mild to severe.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IITrial ID2023-508530-34-00Protocol codeCBYL719F12201Estimated enrolment314 patientsSponsorNovartis Pharma AG

sourced from the EU Clinical Trials Register and site verification

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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).