This category page covers biotechnology and pharmaceutical companies developing therapies that target [astrocyte](/cell-types/astrocytes) dysfunction and [reactive gliosis](/mechanisms/reactive-astrogliosis) in Alzheimer's disease (AD). Astrocytes are the most abundant glial cell type in the human brain, performing critical homeostatic functions including glutamate uptake, potassium buffering, metabolic support, blood-brain barrier maintenance, and synaptic regulation. In Alzheimer's disease, astrocytes undergo reactive transformation — shifting from their healthy supportive state to a phenotype that can either promote or suppress neurodegeneration depending on the context["@liddelow2020"][@escott2023].
The therapeutic approaches in this space target multiple aspects of astrocyte dysfunction:
Research has established that reactive astrocytes exist on a spectrum with at least two broadly characterized states[@liddelow2020][@miller2022]:
[Astrocytes](/cell-types/astrocytes) are the primary cells responsible for clearing glutamate from the synaptic cleft via EAAT2 (GLT-1) transporters. In AD:
Astrocytes support neuronal energy metabolism through the astrocyte-neuron lactate shuttle. In AD:
Astrocytes use calcium signals to regulate synaptic plasticity, vascular tone, and gliotransmission. In AD:
[Athira Pharma](/companies/athira-pharma) (NASDAQ: ATHA) is developing fosgonimeton (ATH-1017), a small molecule activator of the hepatocyte growth factor (HGF) system via the MET receptor. While not exclusively an astrocyte therapy, HGF/MET signaling in astrocytes is a key mechanism of the drug's action[@athira].
| Attribute | Details |
|-----------|--------|
| Lead Program | Fosgonimeton (ATH-1017) |
| Mechanism | HGF/MET receptor activator |
| Indication | Alzheimer's disease |
| Stage | Phase 2/3 (ACT-AD study, recruiting) |
| Key Advantage | Oral, brain-penetrant, no ARIA risk |
Astrocyte Connection: HGF is produced by astrocytes and acts on both astrocytes and neurons. Activating MET signaling promotes astrocyte survival and function, supports neurogenesis, modulates neuroinflammation, and improves cerebral blood flow — all pathways that restore astrocyte homeostatic capacity.
[Lexeo Therapeutics](/companies/lexeo-therapeutics) (NASDAQ: LXEO) is developing LX1001, an AAV gene therapy that delivers the [APOE](/genes/apoe) protective allele to APOE4 homozygous AD patients via intrathecal administration[@lexeo].
| Attribute | Details |
|-----------|--------|
| Lead Program | LX1001 |
| Mechanism | APOE2 gene delivery (AAVrh.10) |
| Indication | APOE4 homozygous Alzheimer's disease |
| Stage | Phase 1/2 (LEAD trial, FDA Fast Track) |
Astrocyte Connection: APOE is primarily produced by astrocytes in the brain. APOE4 (the AD risk allele) impairs astrocyte function, including lipid transport, glucose metabolism, and tau pathology clearance. Delivering APOE2 restores normal astrocyte lipid metabolism and protective functions. Lexeo also has LX1002 targeting APOE4 heterozygotes.
[Neurocrine Biosciences](/companies/neurocrine-biosciences) (NASDAQ: NBIX) has an early pipeline program (NBI-921) targeting norepinephrine modulation for Parkinson's disease, with potential cross-indication relevance for AD[@neurocrine].
| Attribute | Details |
|-----------|--------|
| Program | NBI-921 |
| Mechanism | Norepinephrine modulation |
| Indication | Parkinson's disease (primary), Alzheimer's (exploratory) |
| Stage | Discovery |
Astrocyte Connection: The locus coeruleus (noradrenergic system) projects to astrocytes and provides key trophic support. Noradrenergic inputs regulate astrocyte reactivity, glutamate uptake, and metabolic coupling. Loss of norepinephrine in AD contributes to astrocyte dysfunction. Modulating this system could restore astrocyte homeostasis.
[Novo Nordisk](/companies/novo-nordisk) (NYSE: NVO) is developing semaglutide and other GLP-1 receptor agonists for Alzheimer's disease based on emerging clinical evidence[@novo].
| Attribute | Details |
|-----------|--------|
| Programs | Semaglutide (oral), liraglutide |
| Mechanism | GLP-1 receptor agonist |
| Indication | Alzheimer's disease |
| Stage | Phase 3 trials (SELECT trial for semaglutide) |
Astrocyte Connection: GLP-1 receptors are expressed on astrocytes. GLP-1 agonists reduce neuroinflammation (including astrocyte reactivity), improve cerebral glucose metabolism, reduce tau phosphorylation, and provide neuroprotective effects through astrocyte-mediated pathways.
Lundbeck's Lu AF20513 is an amyloid-TREM2 targeting vaccine that also modulates astrocyte function through microglial-astrocyte cross-talk.
Prothelia's PRX005 (anti-tau antibody) indirectly affects astrocyte pathology by reducing tau burden, which improves astrocyte-neuron interactions.
| Company | Drug/Program | Mechanism | Phase | AD Relevance |
|---------|-------------|-----------|-------|--------------|
| Athira Pharma | Fosgonimeton | HGF/MET activator | Phase 2/3 | Astrocyte survival, neurotrophic support |
| Lexeo Therapeutics | LX1001 | APOE2 gene therapy | Phase 1/2 | Astrocyte lipid metabolism |
| Lexeo Therapeutics | LX1002 | APOE2 gene therapy | Preclinical | Astrocyte lipid metabolism |
| Novo Nordisk | Semaglutide | GLP-1 agonist | Phase 3 | Astrocyte glucose metabolism, inflammation |
| Novo Nordisk | Liraglutide | GLP-1 agonist | Phase 2 | Astrocyte glucose metabolism, inflammation |
| Neurocrine Biosciences | NBI-921 | Norepinephrine modulator | Discovery | Astrocyte trophic support |
| Lundbeck | Lu AF20513 | TREM2/amyloid vaccine | Phase 1 | Microglia-astrocyte cross-talk |
| Strategy | Target | Companies | Status |
|---------|--------|-----------|--------|
| HGF/MET Activation | Astrocyte survival & function | Athira | Phase 2/3 |
| APOE2 Delivery | Astrocyte lipid metabolism | Lexeo | Phase 1/2 |
| GLP-1 Receptor Agonism | Astrocyte metabolism & inflammation | Novo Nordisk | Phase 3 |
| Norepinephrine Modulation | Astrocyte trophic support | Neurocrine | Discovery |
| TREM2/Microglial | Astrocyte-microglia cross-talk | Lundbeck, others | Phase 1 |
| Glutamate Transporter | EAAT2/GLT-1 restoration | Research stage | Preclinical |
Astrocytes in Alzheimer's disease undergo significant functional changes that drive neurodegeneration:
Therapies targeting these mechanisms aim to shift astrocytes back toward a neuroprotective state, restore homeostatic functions, and re-establish supportive neuron-astrocyte interactions.
The following diagram shows the key molecular relationships involving ad-astrocyte-reactivity-companies discovered through SciDEX knowledge graph analysis: