Understanding and predicting inflammation after brain haemorrhage: the INFINITE study takes centre stage
A neurologist at Toulouse University Hospital and a specialist in intracerebral haemorrhage and advanced imaging (MRI, PET), Pr Nicolas Raposo coordinates the scientific and technical aspects of the INFINITE study (Role of neuroINFlammation, and blood‑brain barrier breakdown IN InTracerebral haemorrhagE) within TIPITCH. After spending time at Harvard University in Boston — where he met two other TIPITCH contributors, Pr Grégoire Boulouis and Pr Marco Pasi (CHRU Tours) — he now leads several major studies on intracerebral haemorrhage.
He explains here the scientific ambitions of INFINITE, a project unprecedented in France and internationally.
“INFINITE explores a missing link: understanding neuroinflammation before it becomes visible on CT scan.”
What is the main objective of the INFINITE study, and how does it fit within TIPITCH?
INFINITE is part of Work Package 3, which focuses on reducing inflammation caused by brain haemorrhage.
Within this module, we also find the DARLENE study, which tests a pharmacological treatment aimed at modulating the inflammatory response. It is, in some sense, the final step of the module: testing the drug.
INFINITE is positioned further upstream in the process:
its goal is to better understand, detect and quantify neuroinflammation around the haematoma, using modern imaging tools that may be more sensitive than standard imaging.
CT scan currently shows the oedema surrounding the haematoma, which likely represents a late stage of the neuroinflammatory cascade after intracerebral haemorrhage. But thanks to animal models, we know that inflammation begins within the very first hours. INFINITE aims to assess whether modern tools can capture neuroinflammation earlier than CT.
“We want to image an inflammation that remains invisible on conventional imaging.”
Which tools are you using to detect this very early inflammation?
The study relies on three complementary modalities:
- A TSPO PET scan, which visualises microglial activation — a marker of neuroinflammation.
- Advanced MRI, using a specific sequence (DCE‑MRI) to image blood–brain barrier disruption, a key feature of oedema.
- Blood sampling to measure inflammatory biomarkers.
All examinations take place 10 days after the haemorrhage (Day 10), and patients are seen again at 6 months to assess neurological recovery using the modified Rankin Scale.
Our hypothesis is that patients with poorer neurological recovery at 6 months are those who showed more marked early neuroinflammation.
This study will determine whether early measurement of inflammation can predict clinical outcomes.
“INFINITE could help better identify future candidates for anti‑inflammatory treatments.”
What is the connection with the DARLENE trial?
DARLENE will test a drug targeting inflammation. But, as is often the case, not all patients may respond in the same way.
INFINITE aims to provide tools to:
- identify patients with significant neuroinflammation, and
- potentially predict who stands to benefit most from treatments such as that evaluated in DARLENE.
In other words, INFINITE could become a stratification tool for future therapeutic trials.
“INFINITE is a rare multicentre study — almost unique worldwide.”
Which centres are participating, and why these centres?
Three centres are involved:
- CHU Toulouse
- CHU Bordeaux (Pr Igor Sibon, PI)
- CHU Montpellier (Dr Adrien Ter Schiphorst, PI)
Why not more?
Because the imaging used — a specific PET radiotracer, DPA‑714 — has a very short half‑life.
It is produced in Toulouse, which requires geographical proximity.
Moreover, very few centres are able to perform, in patients in the acute phase of intracerebral haemorrhage:
- a PET scan,
- an advanced MRI,
- and blood sampling,
all on the same day.
INFINITE is therefore both a demanding and highly specialised study.
An ambitious study supported by exceptional expertise and resources
What is the planned sample size and timeline?
The study will include 117 patients over approximately 36 months, with a launch planned for spring 2026.
This is an ambitious target, as performing such imaging in this clinical context is rare and complex. To date, worldwide, only two studies have combined PET scan and MRI of the blood–brain barrier in the acute phase of intracerebral haemorrhage — and each on fewer than 10 patients.
INFINITE will therefore be one of the first multicentre studies of this scale.
“The ultimate goal: understand, predict, and treat better.”
What are the next steps if your hypotheses are confirmed?
If INFINITE shows that neuroinflammation measured at Day 10 is a key factor in poor prognosis, several advances could follow:
- better selection of candidates for therapeutic trials such as DARLENE,
- the development of more personalised treatments,
- improved timing of intervention,
- and ultimately, better neurological outcomes for patients with intracerebral haemorrhage.
INFINITE is therefore a strategic piece of the TIPITCH puzzle: better understanding to treat better.
Any final thoughts?
Pr Raposo wishes to thank all TIPITCH partners for their support and enthusiasm, as well as the scientific and methodological teams in Toulouse (Inserm U1214 TONIC, Clinical Investigation Centre), and the investigator sites in Bordeaux and Montpellier, whose expertise in advanced imaging has made it possible to structure such an ambitious study.
Key expertise mobilised for INFINITE
The INFINITE study is built on a particularly strong foundation of expertise in Toulouse.
- Pr Pailloux, nuclear medicine specialist, brings unique experience with the DPA‑714 PET radiotracer, essential for visualising neuroinflammation.
- Patrice Peran leads advanced analysis of MRI sequences, particularly those assessing blood–brain barrier disruption.
- Dr Claire Thalamas and the team from the Clinical Investigation Centre at CHU Toulouse ensured methodological structuring of the study — from design to sample size calculation — a decisive contribution to carrying out such an ambitious protocol.
