RecruitingPHASE2INTERVENTIONAL

A Phase 2 Study of Mutant-selective PI3Kα Inhibitor, RLY-2608, in Adults and Children With PIK3CA Related Overgrowth Spectrum and Malformations Driven by PIK3CA Mutation

This study is looking at a new medicine called RLY-2608, which targets a specific genetic error (a PIK3CA mutation) that can lead to conditions where parts of the body grow too much or develop abnormally. These conditions include things like Lymphatic Malformations, CLOVES Syndrome, and Klippel Trenaunay Syndrome. The study involves adults and children and is being carried out in three parts. Researchers want to find the right dose of the medicine and then see how safe and effective it is. In the final part, some participants will receive the new medicine and others a placebo (a dummy medicine), so the researchers can compare the effects. It's hoped that this new medicine might offer a way to help manage these conditions.

At a glance

Status

Recruiting

Phase

PHASE2

Sponsor

Relay Therapeutics, Inc.

Enrolment target

277

Start

13 Jun 2025

Estimated completion

01 Oct 2031

What is this study about?

This study is all about a new investigational medicine called RLY-2608. It's designed for people, both adults and children, who have certain conditions where parts of their body have grown or developed unusually. These conditions are often grouped under the name PIK3CA-Related Overgrowth Spectrum (PROS), and they happen because of a specific change, or 'mutation', in a gene called PIK3CA. This gene plays a role in how cells grow, and when it changes, it can cause problems like unusual growths or malformations.

The conditions being looked at in this study include Lymphatic Malformations, Vascular Malformations, CLOVES Syndrome, Klippel-Trenaunay Syndrome, and Megalencephaly-capillary Malformation Polymicrogyria Syndrome (MCAP). These are all different ways the PIK3CA gene change can show up in the body. The new medicine, RLY-2608, is designed to specifically target and block the effects of this changed PIK3CA gene, hopefully helping to control or improve the symptoms of these conditions.

The study is divided into three main parts. The first part is about finding the safest and most effective dose of RLY-2608. The second part will look at how the medicine works in different groups of people with these conditions. In the final part, some people will receive RLY-2608 and others will receive a placebo (a treatment that looks exactly like the study medicine but contains no active drug). This helps researchers understand the true effects of the new medicine. By taking part, you could be helping doctors learn more about these conditions and whether RLY-2608 could be a helpful new treatment.

Key takeaways

This study is testing a new medicine (RLY-2608) for specific overgrowth conditions.
It's for both adults and children with conditions linked to a PIK3CA gene change.
The study aims to understand if the medicine is safe and effective.
Some participants will receive the new medicine, others a placebo (dummy medicine).
Participation involves regular clinic visits and health checks.
You can always choose to leave the study at any time.

Who may be eligible?

To be considered for this study, you or your child should have been diagnosed by a doctor with a condition from the PIK3CA-Related Overgrowth Spectrum (PROS), or a similar type of malformation. Crucially, your doctors must have found a specific change in your PIK3CA gene in the affected area of your body, or sometimes in your blood. In some cases, if no other cause for your condition has been found, you might still be considered even without this exact gene change.

Your general health also needs to be reasonably good. For children under 16, a special score called Lansky needs to be 50 or higher, and for adults aged 16 and over, a Karnofsky score of 50 or higher is needed. These scores help doctors understand how well you are able to do daily activities.

There are also reasons why someone might not be able to join the study. For example, if you've had a bad reaction to similar drugs before, have certain serious heart problems, or have had recent treatment for your condition like surgery, radiation, or other medicines within a specific timeframe shortly before the study begins, you might not be eligible. This is to ensure the safety of participants and the clarity of the study results.

Quick self-check

Do you or your child have a medical diagnosis of PROS or a similar malformation?
Has a PIK3CA gene change been found in the affected part of your body or blood?
Is your general health good enough for clinic visits and potential treatment?
Have you *not* had certain treatments (like surgery or specific medicines for your condition) very recently?
Are you able to provide a tissue or fluid sample if needed?

This is a guide only — the research team will confirm whether you can take part.

What does participation involve?

If you decide to take part in this study, you or your child would receive RLY-2608 or a placebo, depending on the study part you are in. This medicine would be given to you following a schedule set by the study doctors. You would have regular visits to the clinic for various assessments, which might include blood tests, physical examinations, and scans to monitor your health and how the treatment is working. Before starting, and potentially during the study, you might be asked to provide a small sample of tissue or fluid from the affected area of your body if it's safe to do so. These samples help researchers understand your condition better and how the medicine might be working. Details about the total length of your participation, how often visits would be, and what specific tests you would have will be fully explained by the study team.

Potential risks and benefits

Taking part in any medical study has potential benefits and risks. You might feel better or your condition could improve with the study medicine, RLY-2608, and you would be contributing to scientific knowledge that could help others in the future. However, there's also a chance the medicine might not work for you, or you could experience side effects, some of which might be unpleasant or potentially serious. The study team will explain all known side effects. You have the right to withdraw from the study at any time, for any reason, without it affecting your usual medical care.

Locations (31)

Phoenix Children's Hospital
Phoenix, United States· Recruiting
Arkansas Children's Hospital
Little Rock, United States· Recruiting
University of California, Los Angeles
Los Angeles, United States· Recruiting
Stanford University
Palo Alto, United States· Recruiting
University of California, San Francisco
San Francisco, United States· Recruiting
Children's Hospital Colorado
Aurora, United States· Recruiting
Children's Hospital of Atlanta
Atlanta, United States· Recruiting
Riley Children's Hospital
Indianapolis, United States· Recruiting
Johns Hopkins Medical Institute
Baltimore, United States· Recruiting
Boston Children's Hospital
Boston, United States· Recruiting
Corewell Health
Grand Rapids, United States· Recruiting
Mayo Clinic
Rochester, United States· Recruiting

+19 more sites — see the official record for the full list.

Common questions

What is a PIK3CA mutation?

A PIK3CA mutation is a specific change in a gene that helps control cell growth. When this gene changes, it can sometimes lead to parts of the body growing too much or developing unusually.

What is PIK3CA-Related Overgrowth Spectrum (PROS)?

PROS is a group of conditions where parts of the body grow larger than normal or develop in unusual ways, all linked to changes in the PIK3CA gene.

What is a placebo?

A placebo is a 'dummy' treatment that looks just like the real study medicine but contains no active drug. It helps researchers compare the true effects of the new medicine.

Who is running this study?

The study is sponsored by a pharmaceutical company and carried out by medical researchers at hospitals or clinics. They will oversee your care throughout the study.

Will I or my child definitely get the new medicine?

Not necessarily. In the final part of the study, participants are randomly assigned to either receive RLY-2608 or a placebo, so researchers can compare the results fairly.

How to find out more

Relay Therapeutics, Inc

ClinicalTrials@relaytx.com 617-322-0731 Official trial record

Always speak to your GP or specialist before deciding to take part in a study.