PNOC023 (diffuse midline glioma (DMG))

Recruiting

Who can enter

• Children with diffuse midline glioma (DMG; newly diagnosed or recurrent) or with a recurrent high grade tumor of the central nervous system

• Age: from  12 years and older

Goal

The goal of this study is to find out whether the new medicine ONC206 is safe and whether it may help children with a DMG or a recurrent high grade tumor of the central nervous system. Researchers want to learn which dose works best and what side effects may occur.

Background

A DMG or a recurrent high grade tumor is a difficult-to-treat brain tumor. Current treatment options are limited. Therefore, new, potentially more effective treatments are needed. In laboratory studies, ONC206 has shown the ability to kill tumor cells without harming healthy cells. The medicine seems to be well tolerated so far.

Researchers expect that ONC206 may slow tumor growth or kill tumor cells, while leaving healthy cells unharmed. They also expect that the medicine will be safe to use during and after radiation therapy.

The study consists of three parts:

1. Determining which dose of ONC206 is safe

2. Learning more about this safe dose of ONC206

3. Measuring how much of the medicine ONC206 reaches the tumor 

Before the study starts, there is a screening period of up to 4 weeks. During this period, you will have a physical examination, blood tests, an MRI scan, and researchers will check whether you can participate in the study.

If you are eligible, you will receive the medicine ONC206. Depending on the treatment you receive as part of standard care, you will use the medicine ONC206:

• Before surgery 

• During radiation therapy

• After radiation therapy (applicable for all participants)

One cycle of ONC206 lasts four weeks. Each week, you take ONC206 for three consecutive days. The study determines whether you take the medicine once or twice daily. ONC206 is a powder that is dissolved in water or clear apple juice and then taken by mouth.

During any surgery and treatment, your health will be closely monitored. At the start of each cycle, you will have a physical examination and blood will be drawn. Sometimes extra blood samples are needed for the study.

In some cycles, additional tests may be required, such as an MRI scan, a lumbar puncture, or collection of a stool sample. You and your parents will regularly complete questionnaires about how you are doing. For the study, these questionnaires are more frequent and more detailed.

In order to participate in a study please refer to your/your child’s doctor.
For international patients: please feel welcome to contact our International Patients Office.

Last reviewed
March 13, 2026

The above information is intended as a brief summary only and may not reflect the most up-to-date information. For full details and the current status of a protocol, physicians can contact the Princess Máxima Center directly.