This is a global breakthrough against the most feared pediatric cancer. On April 24, 2026, the journal Nature Medicine publishes the results of phase 2 of the BIOMEDE trial, supported for ten years by Imagine for Margo with €2.5 million. Four children with diffuse intrinsic pontine glioma are still alive more than six years after their diagnosis — a historic first in a disease that was previously considered incurable.
For more than fifty years, diffuse intrinsic pontine glioma (DIPG) has remained the worst enemy of pediatric oncologists: an inoperable tumor, located at the heart of the brain, in an area that controls breathing, movement and vital functions. A median survival of less than one year. No progress since the 1970s. On April 24, 2026, the scientific journal Nature Medicine publishes the results of the international clinical trial BIOMEDE, led and coordinated by Gustave Roussy. And for the first time in the history of this disease, four “long-term survivors” more than six years after their diagnosis.
For Imagine for Margo, a French association committed to fighting pediatric cancers, this publication marks the culmination of ten years of commitment and €2.5 million invested. A look back at a breakthrough no one expected anymore, and at the community that made it possible.
What is diffuse intrinsic pontine glioma (DIPG)?
Diffuse intrinsic pontine glioma is a rare and aggressive pediatric brain tumor that affects 40 to 50 children and young adults each year in France. It develops in the brainstem, the area that connects the brain to the spinal cord and controls vital functions.
Two characteristics make this tumor particularly difficult to treat: its deep location in the brain, which rules out any conventional surgical intervention, and its infiltrative nature, which makes it impossible to remove without damaging essential tissues. Until now, only radiotherapy offered temporary benefit, without allowing a cure. Median survival remains less than one year after diagnosis.
How is the diagnosis made?
The diagnosis of DIPG mainly relies on a brain MRI, performed when the child shows suggestive neurological symptoms: balance disorders, vision abnormalities, facial paralysis, difficulty swallowing or speaking. The BIOMEDE trial introduced a major evolution: biopsy of the brainstem, a highly precise surgical procedure made possible by advances in imaging and neurosurgery. This biopsy now makes it possible to genetically analyze each tumor and guide treatments in a personalized way.
BIOMEDE: the largest clinical trial in the world on this cancer
Launched in 2014 by Gustave Roussy under the coordination of Dr Jacques Grill and Prof Marie-Anne Debily, BIOMEDE is the first international clinical trial in precision medicine dedicated to DIPG. Its phase 2 included patients between 2014 and 2019, mobilizing teams in France, the United Kingdom, Denmark, Sweden, Australia, Spain and the Netherlands. France, as coordinator, included 72% of patients.
Each tumor underwent in-depth molecular analysis, creating the largest biological database ever assembled on this disease. Patients were assigned to one of the three targeted treatments tested — dasatinib, erlotinib or everolimus — depending on the molecular profile of their tumor, in addition to radiotherapy.
Why was Imagine for Margo’s role decisive?
From 2014, Imagine for Margo chose to invest in BIOMEDE at a time when public funding struggled to cover the scale of the project. The association funded three key pillars of the trial:
- Training neurosurgeons in brainstem biopsy across participating centers
- Full genomic sequencing of each tumor, the foundation of precision medicine
- European infrastructure: shipment and centralized analysis of samples, secure data-sharing platform, and delivery of innovative treatments across the sixteen participating countries
In 2025, the association allocated an additional €890,214 to support the European expansion of the program, bringing the total amount to €2.5 million since 2016.
Four “long-term survivors” six years after diagnosis: what the science says
The most striking result of the publication in Nature Medicine is the documentation of four “long-term survivors”: four children diagnosed more than six years ago and still alive today. In a disease where median survival is measured in months, these cases are not just exceptions: they open an unprecedented scientific window into the biological mechanisms that may, in rare circumstances, allow the body to sustainably control the tumor.
Three discoveries that will change patient care
The molecular analysis of tumors from long-term survivors and about ten other patients who survived more than two years revealed three major findings:
- A distinct immune microenvironment. Tumors from long-term survivors show a more active local immune response, opening a new therapeutic pathway: immunotherapy.
- The decisive role of the TP53 gene. Mutation of the TP53 gene is associated with a poorer prognosis. This marker is now integrated into patient stratification for future trials.
- Everolimus as a new standard. Among the three targeted treatments tested, everolimus stands out with a significantly better tolerance profile — only 3% of treatment discontinuations due to toxicity, compared to 14% for dasatinib and 20% for erlotinib.
“BIOMEDE is the story of a community that refused the unacceptable. Behind every euro invested, there is a runner, a family, a company, a child. Seeing today, more than ten years later, four ‘long-term survivors’ and an unprecedented biological map of the disease moves us as much as it commits us to continue our efforts in order to one day completely eradicate this terrible disease. These first victories, we owe them to the teams at Gustave Roussy, who carried this scientific ambition with exemplary rigor and determination, and to all those who trusted pediatric research.”
Patricia Blanc — President and founder of Imagine for Margo
And now? BIOMEDE 2.0, BIOMEDE AI and ELICIT
The teams do not intend to stop there. Three new programs are already extending the legacy of BIOMEDE, all supported by Imagine for Margo.
BIOMEDE 2.0: comparing next-generation treatments
Open in ten European countries, BIOMEDE 2.0 is the only international comparative clinical trial dedicated to malignant midline and brainstem gliomas. It is recruiting 368 patients over four years and compares everolimus — now established as the new standard — with ONC201 (dordaviprone), the first molecule of a new class of anticancer drugs.
BIOMEDE AI: leveraging the world’s largest dataset
Ten years of the trial have generated an unprecedented volume of biological, genomic and imaging data. The BIOMEDE AI program uses artificial intelligence to extract insights inaccessible to human analysis: identifying new biomarkers, predicting treatment responses, and accelerating the discovery of therapeutic targets.
ELICIT: the immunotherapy pathway
The newest trial, ELICIT, was funded in 2025 as part of Fight Kids Cancer, a European coalition in which Imagine for Margo is a key member. It will explore the contribution of CAR-T cells — a revolutionary immunotherapy technology — in combination with treatments validated by BIOMEDE. Its opening is scheduled for 2027.
RUNNING FOR RESEARCH IN 2026
A significant part of BIOMEDE’s funding comes from the Enfants sans Cancer races.
Each race bib directly funds pediatric research.
Tuesday, June 2, 2026 · Enfants sans Cancer City — Paris La Défense
Sunday, September 27, 2026 · Enfants sans Cancer — Domaine national de Saint-Cloud & connected edition
Frequently asked questions about BIOMEDE and diffuse intrinsic pontine glioma
What is the BIOMEDE trial?
BIOMEDE is the largest international clinical trial ever conducted on diffuse intrinsic pontine glioma (DIPG), a rare and aggressive pediatric cancer. Launched in 2014 and led by Gustave Roussy, it included patients in seven countries and is based on genetic analysis of each tumor to guide treatment (precision medicine). Its phase 2 was published in Nature Medicine on April 24, 2026.
What is Imagine for Margo’s role in BIOMEDE?
Imagine for Margo has supported BIOMEDE since 2014 with €2.5 million, including €890,214 in 2025. The association funded three essential pillars: training neurosurgeons in brainstem biopsy, genomic sequencing of tumors, and the European infrastructure for sharing samples and data across 16 countries.
Is diffuse intrinsic pontine glioma curable today?
DIPG remains a disease with a poor prognosis, with median survival under one year. However, BIOMEDE has documented for the first time four “long-term survivors” more than six years after diagnosis, as well as about ten other patients surviving more than two years. These cases open concrete research pathways, particularly toward immunotherapy, and raise hope for future curative treatments.
What new treatments are being studied after BIOMEDE?
Three programs extend BIOMEDE: BIOMEDE 2.0, comparing everolimus with ONC201 (dordaviprone) in 368 patients across 10 European countries; BIOMEDE AI, using artificial intelligence to analyze trial data; and ELICIT, an immunotherapy trial using CAR-T cells, scheduled to open in 2027.
How can we support research against childhood cancer?
Imagine for Margo collects donations year-round on imagineformargo.org. A significant part of funding comes from the Enfants sans Cancer races, held twice a year: June 2, 2026 in Paris La Défense (Enfants sans Cancer City) and September 27, 2026 at Domaine national de Saint-Cloud, with a connected edition worldwide. Each registration and each donation directly contributes to pediatric research.
To read also on imagineformargo.org:
- Fight Kids Cancer — the European coalition against pediatric cancers
- Enfants sans Cancer: how to register
- Our research programs funded in 2025
Article written by Maxime Roques — Head of Communication and Marketing at Imagine for Margo