Hypothesis

A TSPO-PET guided neuroinflammation therapy will demonstrate regulatory approval by 2028 through evidence that converting microglial activation from smoldering to reparative phenotypes enables quantifiable remyelination in progressive MS.

Biological Mechanism

The translocator protein (TSPO) is upregulated on activated microglia and serves as a biomarker of neuroinflammation. In progressive MS, smoldering plaques maintain a rim of chronically activated microglia that prevent remyelination and promote axonal injury.

Therapeutic intervention targeting these microglial populations can shift them from a pro-inflammatory to a pro-reparative phenotype, enabling oligodendrocyte precursor cells to differentiate and remyelinate denuded axons. This mechanism transforms non-healing chronic lesions into actively repairing tissue.

Real-World Backing

Imaging Biomarker Validation: The SMART in MS trial (NCT05147532) directly links neuroinflammation to remyelination potential. It uses dual-tracer PET imaging:

• [18F]-Florbetaben: Binds myelin to quantify demyelination and remyelination dynamics
• [18F]-DPA-714: Binds TSPO to map microglial activation

The primary outcome measures the proportion of demyelinated voxels at baseline that become remyelinated at 6 months���establishing the quantifiable link between inflammatory activity and repair capacity.

Active Clinical Trials

| Trial | Phase | Population | Intervention | Primary Measure | |-------|-------|------------|--------------|-----------------| | NCT03691077 | Phase 3 | Relapsing/PPMS | Ocrelizumab | Microglial activation via �����F-DPA714 PET | | NCT05805839 | Phase 2 | MS spectrum | TSPO PET imaging | Association with disability accumulation | | NCT05783934 | N/A | Progressive/RRMS | �����F-Florbetaben PET | Smoldering plaque characterization |

Regulatory Pathway

The combination of validated imaging biomarkers (myelin PET, TSPO PET) with clinical disability outcomes (EDSS) creates a regulatory framework where neuroinflammation reduction and repair can be simultaneously demonstrated.