RecruitingPHASE1, PHASE2INTERVENTIONAL

5G-PEARL: Paxalisib in Malignant Brain Tumours

The 5G-PEARL study is a clinical trial investigating a new treatment approach for aggressive brain tumours, specifically glioblastoma. Researchers are combining two existing drugs, paxalisib and temozolomide, to see how safe they are together and if they can effectively fight the cancer. This trial includes two main parts: an early phase to check safety and find the right dose, and a later phase to see how well the treatment works. Participants will have their tumours checked for specific genetic changes, which helps guide the treatment. This research is important for finding new ways to treat these challenging brain cancers and improve patient outcomes.

At a glance

Status

Recruiting

Phase

PHASE1, PHASE2

Sponsor

Institute of Cancer Research, United Kingdom

Enrolment target

Start

19 Jan 2026

Estimated completion

30 Jun 2029

Malignant Primary Gliomas Glioblastoma Multiforme (GBM)

What is this study about?

The 5G-PEARL study is a research project looking into new ways to treat a type of aggressive brain tumour called glioblastoma. We know these tumours can be very difficult to treat, so doctors are constantly searching for better options. This study focuses on combining two medicines: paxalisib and temozolomide. Temozolomide is a common chemotherapy drug used for glioblastoma, and paxalisib is a newer drug being investigated for its potential to stop cancer cells from growing.

The main goals of this study are twofold. First, the researchers want to make sure the combination of paxalisib and temozolomide is safe for patients and to find the best dose to use. This is called Phase 1b. Once they know it's safe and at what dose, they'll move to Phase 2 to see how well this combined treatment actually works against the brain tumours. This study is part of a larger programme called 5G, which aims to use detailed information about a patient's tumour, like its genetic makeup, to guide treatment decisions.

Patients taking part in this study will have their tumours checked for specific genetic changes, or 'biomarkers'. These biomarkers help doctors understand if a patient's tumour might respond better to this particular treatment combination. By focusing on these tumour characteristics, the study hopes to find a more personalised and effective way to treat glioblastoma.

Key takeaways

This study is testing a new combination of two drugs, paxalisib and temozolomide, for aggressive brain tumours (glioblastoma).
It aims to see if the combination is safe and effective in fighting the cancer.
Your tumour's unique genetic features will help guide whether this treatment might be suitable for you.
Regular hospital visits, blood tests, and scans will be part of the study to monitor your health and the treatment's effect.
Participation is voluntary, and you can withdraw at any time.

Who may be eligible?

This study is looking for people aged 16 years or older who have been diagnosed with a specific type of aggressive brain tumour called glioblastoma (WHO Grade IV, specifically Glioblastoma, IDH-wildtype Grade 4). You would have already had surgery to remove as much of the tumour as possible, and then received standard chemotherapy and radiotherapy treatment.

Important conditions for joining include having specific genetic information about your tumour available through a programme called the Minderoo Precision Brain Tumour Programme. You also need to be generally well enough to take part, with a good quality of life and stable brain function. Your doctor will check your overall health through blood tests to make sure your body can handle the treatment. Unfortunately, if your tumour is growing again after your initial treatment, you wouldn't be able to join this particular study.

Quick self-check

Are you 16 years or older?
Do you have a diagnosis of Glioblastoma (WHO Grade IV, IDH-wildtype Grade 4)?
Have you completed initial surgery, chemotherapy, and radiotherapy?
Are you generally well and stable, with good blood test results?
Is your tumour currently stable and not growing after your previous treatments?

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

What does participation involve?

If you join this study, you will be given both paxalisib and temozolomide. Paxalisib will be taken as a tablet once a day. Temozolomide will also be taken as a capsule once a day, for five days in a row, every 28 days. The study will start with a lower dose of both medications, and the doctors might increase the dose of paxalisib in the second month and temozolomide in the third month if you are tolerating them well and not having too many side effects.

You will need to have regular visits to the hospital for checks, blood tests, and scans to see how you are responding to the treatment and to monitor for any side effects. Your team will explain the exact schedule of visits, but these studies typically involve frequent check-ups, especially in the beginning, and then potentially less often as the study progresses. The total length of your participation would depend on how well you respond to the treatment and if any side effects occur.

Potential risks and benefits

Taking part in any clinical trial has potential benefits and risks. The main potential benefit of this study is that the combination of paxalisib and temozolomide might be more effective at shrinking your brain tumour or slowing its growth than current standard treatments. It also offers access to a new drug that isn't yet widely available. However, there are potential risks, as both drugs can cause side effects. These could include feeling sick, tiredness, changes in your blood counts, or other reactions. The research team will carefully monitor you for any side effects and will explain all known risks before you decide to participate. Remember, your participation is completely voluntary, and you can withdraw from the study at any time without affecting your future medical care.

Locations (1)

Royal Marden NHS Foundation Trust
Sutton, United Kingdom· Recruiting

Common questions

What is Glioblastoma?

Glioblastoma is a fast-growing and aggressive type of brain cancer that develops from star-shaped brain cells called astrocytes. It's one of the most common and serious forms of brain tumour in adults.

What are paxalisib and temozolomide?

Temozolomide is a chemotherapy drug commonly used to treat brain tumours. Paxalisib is a newer drug being tested that aims to block certain signals in cancer cells, potentially slowing their growth.

What does 'biomarker-guided' mean?

This means doctors will check your tumour for specific genetic changes, or 'biomarkers'. These changes can help them understand if your cancer is more likely to respond to this particular treatment.

Will I get the new drug or a placebo?

In this study, all participants will receive the combination of paxalisib and temozolomide. There is no placebo group where patients receive a dummy treatment.

Can I stop participating if I want to?

Yes, your participation is entirely voluntary. You can choose to leave the study at any time, for any reason, without it affecting your ongoing medical care.

How to find out more

5G Team

5G-enquiries@icr.ac.uk 0203 437 6003 Official trial record

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