The glymphatic system is a macroscopic waste clearance pathway in the brain that utilizes perivascular tunnels formed by astroglial AQP4 water channels to clear soluble amyloid-beta (Aβ), tau proteins, and other metabolic waste products during sleep. Cerebrospinal fluid (CSF) dynamics — including CSF production, circulation, and drainage — are integral to this brain clearance system.
In Alzheimer's disease, glymphatic clearance becomes significantly impaired, contributing to accumulation of toxic protein aggregates. This category page catalogs companies developing therapies targeting:
Cyclia Therapeutics is developing therapies targeting the glymphatic system for neurodegenerative disease:
| Attribute | Details |
|---|---|
| Focus | Glymphatic system enhancement |
| Platform | Perivascular clearance modulation |
| Indication | Alzheimer's disease, Parkinson's disease |
| Stage | Preclinical |
| Mechanism | AQP4 polarization enhancement |
Scientific Rationale: The glymphatic system relies on AQP4 water channels in astrocyte end-feet surrounding cerebral blood vessels. Cyclia is developing small molecules and biologics to enhance AQP4 polarization and perivascular flow, potentially improving clearance of Aβ and tau from the brain parenchyma.
Vera Therapeutics is focused on CSF dynamics and brain waste clearance:
| Attribute | Details |
|---|---|
| Focus | CSF production and flow |
| Platform | CSF dynamics modulation |
| Indication | Alzheimer's disease, Normal Pressure Hydrocephalus |
| Stage | Preclinical |
Innovation: Vera is targeting CSF production via the choroid plexus and improving CSF circulation through the ventricular system and subarachnoid space. Enhanced CSF flow may improve clearance of solutes from the brain interstitium via the glymphatic pathway.
Alnylam is pioneering RNA interference (RNAi) therapeutics with a focus on brain delivery through transferrin receptor (TfR)-targeting:
| Attribute | Details |
|---|---|
| Focus | siRNA delivery to brain via TfR |
| Platform | GALNAC-conjugated siRNA with TfR targeting |
| Indication | CNS diseases including AD |
| Stage | Preclinical |
Innovation: Alnylam's TfR-targeted approach enables siRNA delivery across the BBB. The company has explored reducing production of amyloid precursor protein (APP) in the brain as a potential disease-modifying approach. Additionally, siRNA targeting AQP4 may modulate glymphatic function.
Cyclocera developed AC-1204 (Ketasulin), a compound designed to improve cerebral glucose metabolism:
| Attribute | Details |
|---|---|
| Focus | Cerebral glucose metabolism, sleep-dependent clearance |
| Lead Candidate | AC-1204 (Ketasulin) |
| Indication | Alzheimer's disease |
| Stage | Phase 3 (discontinued 2019) |
| Mechanism | Ketogenic agent |
Rationale: Cerebral glucose hypometabolism is a hallmark of AD. Additionally, sleep-dependent glymphatic clearance is enhanced during ketogenesis. By providing an alternative fuel source (beta-hydroxybutyrate), Ketasulin aimed to improve neuronal energy supply and potentially enhance sleep-dependent waste clearance.
Cereve (formerly Edison Therapeutics) focused on mitochondrial protection in neurodegenerative disease:
| Attribute | Details |
|---|---|
| Focus | Mitochondrial dysfunction in neurovascular unit |
| Lead Candidate | CVT-31345 |
| Stage | Preclinical |
| Mechanism | Mitochondrial ATP-sensitive potassium channel activators |
Notes: While primarily focused on mitochondrial protection, improved endothelial mitochondrial function supports perivascular pumping and glymphatic clearance. The neurovascular unit's metabolic health is integral to glymphatic system function.
AQP4 (Aquaporin-4) is the primary water channel in the glymphatic system:
| Target | Approach | Companies |
|---|---|---|
| AQP4 polarization | Small molecule modulators | Cyclia Therapeutics |
| AQP4 expression | Gene therapy | Research |
| AQP4 trafficking | Kinase inhibitors | Research |
Meningeal lymphatic vessels drain waste from the brain to cervical lymph nodes:
| Target | Approach | Companies |
|---|---|---|
| Lymphatic growth | VEGF-C agonists | Research |
| Drainage optimization | Physical modulation | Research |
| Inflammation reduction | Anti-inflammatory | Research |
arterial pulsations drive glymphatic flow:
| Target | Approach | Companies |
|---|---|---|
| Pulse amplitude | Vasomodulators | Research |
| Vessel compliance | Smooth muscle modulators | Research |
| Astrocyte end-feet | AQP4 enhancers | Cyclia |
Sleep is essential for maximal glymphatic activity:
| Target | Approach | Companies |
|---|---|---|
| Sleep optimization | Orexin antagonists | Multiple |
| Circadian entrainment | Light/melatonin therapy | Multiple |
| Metabolic state | Ketogenic agents | Cyclocera |
CSF production and flow are foundational to glymphatic function:
| Target | Approach | Companies |
|---|---|---|
| Choroid plexus function | CSF production modulators | Vera Therapeutics |
| Ventricular flow | Intranasal delivery | Research |
| Subarachnoid circulation | Physical therapy | Research |
| Company | Drug/Approach | Phase | Indication | Status |
|---|---|---|---|---|
| Cyclia Therapeutics | AQP4 modulators | Preclinical | AD | Development |
| Vera Therapeutics | CSF dynamics | Preclinical | AD/NPH | Development |
| Alnylam | siRNA brain delivery | Preclinical | AD | Development |
| Multiple | Orexin antagonists | Phase 2/3 | AD | Active |