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

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What is this trial about?

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

This clinical trial focuses on studying PIK3CA-Related Overgrowth Spectrum (PROS), a condition that causes abnormal tissue growth in various parts of the body. The study will test a medication called alpelisib (also known as BYL719), which is available as film-coated tablets and granules that are taken by mouth.

The purpose of this study is to determine how well alpelisib works in treating both adults and children (age 2 and older) who have PROS. The medication will be given daily at doses up to 250 milligrams for a treatment period lasting up to 168 weeks.

During the study, participants will have their tissue growths measured using MRI scans to see if they shrink in response to the treatment. The study will also monitor pain levels, overall symptoms, and any side effects that may occur. Participants will be checked regularly for changes in their condition, including how the medication affects their daily activities and quality of life.

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 evaluation

    Your condition will be assessed to confirm the presence of PIK3CA-related overgrowth spectrum (PROS)

    Medical tests will be performed to verify adequate bone marrow and organ function

    A measurable lesion of at least 2 cm will be identified and evaluated

  2. Step 2

    Treatment initiation

    You will begin taking alpelisib (BYL719) orally

    The medication comes in two forms: film-coated tablets or granules

    Regular evaluations of your response to treatment will be scheduled

  3. Step 3

    Ongoing assessments

    Your PROS lesions will be measured regularly using MRI scans

    Pain levels will be evaluated using specific assessment tools

    Blood samples will be taken to measure medication levels in your body

    Any new symptoms or side effects will be monitored and recorded

  4. Step 4

    Treatment monitoring

    Regular checks of vital signs and laboratory values will be performed

    Cardiac function will be assessed periodically

    If you are of applicable age, growth, bone/dental development, and sexual maturation will be monitored

  5. Step 5

    Long-term follow-up

    Your progress will be tracked until 2030

    Any PROS-related symptoms and complications will be monitored

    Healthcare visits and any required surgical procedures will be documented

Who can join the trial?

7 criteria

  • Must be at least 2 years old at the time of giving consent
  • Must have a confirmed diagnosis of PROS (PIK3CA-Related Overgrowth Spectrum) with symptoms that are getting worse over time. The condition must affect multiple body areas or have specific features (single enlarged finger/toe, enlarged head, or skin marks alone are not eligible)
  • Must have a confirmed PIK3CA gene mutation through DNA testing, and tissue samples must be available or obtainable through biopsy if medically safe
  • Must have adequate physical functioning ability: - For participants over 16 years: Karnofsky score of 50 or higher (able to care for self but unable to work or do normal activities) - For participants 16 years or younger: Lansky score of 50 or higher (requires considerable assistance for daily activities)
  • Must have at least mild severity of symptoms as measured by the Patient Global Impression of Severity (PGI-S) scale during screening
  • Must have normal bone marrow and organ function
  • Must have at least one measurable growth related to PROS that is: - At least 2 centimeters in size - Confirmed by medical imaging experts - Causing problems, symptoms, or limitations in daily life

Who cannot join the trial?

14 criteria

  • Age below 2 years old
  • Presence of active malignancy (cancer) or history of cancer in the past 3 years (except for adequately treated non-melanoma skin cancer or cervical cancer)
  • Known hypersensitivity (severe allergic reaction) to alpelisib or its components
  • Severe liver disease or abnormal liver function tests
  • Uncontrolled diabetes (blood sugar levels that are not well managed)
  • Pregnant or breastfeeding women
  • Use of other investigational drugs within 30 days before starting the study
  • Severe heart conditions, including:
    • Recent heart attack
    • Unstable heart rhythm problems
    • Heart failure with symptoms
    • Severe kidney disease requiring dialysis
    • Any medical condition that, in the investigator's opinion, would make participation unsafe
    • Unable to swallow oral medications
    • Mental conditions that prevent understanding of study requirements
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Investigated drugs

Alpelisib (also known as BYL719) is a medication that targets specific genetic changes in the PIK3CA gene. It works by blocking certain proteins that contribute to abnormal cell growth. This medication is designed to treat patients who have a condition called PIK3CA-Related Overgrowth Spectrum (PROS), which causes various parts of the body to grow disproportionately. The medication is taken orally and aims to reduce the overgrowth of tissues affected by this genetic condition.

What is already known about the treatment

Alpelisib (BYL719) - A targeted oral medication specifically designed to treat PIK3CA-Related Overgrowth Spectrum (PROS), which is administered in tablet form taken daily. This drug works by selectively inhibiting the PIK3CA enzyme, which is responsible for cellular growth and division, making it particularly effective in treating conditions caused by PIK3CA gene mutations. Currently undergoing Phase II clinical trials for both pediatric and adult patients, alpelisib represents a promising therapeutic approach in managing PROS conditions, showing potential in controlling abnormal tissue growth patterns. The medication belongs to the class of PI3K inhibitors and is being evaluated for its efficacy, safety, and pharmacokinetic properties in patients aged 2 years and older.

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, muscles, bones, and skin. The overgrowth typically begins during early development and continues throughout life, with symptoms varying widely among individuals. The condition may cause physical differences that become more noticeable over time as the affected areas continue to grow.
Trial detailsLast updated 2 Oct 2026
Age18+ yearsPhasePhase IITrial ID2024-519960-42-00Protocol codeCBYL719F12202Estimated enrolment104 patientsSponsorNovartis Pharma AG

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