Neurotrophin and growth factor therapies represent a fundamental approach to Alzheimer's disease treatment that aims to preserve and restore neuronal function through endogenous neuroprotective pathways. Unlike amyloid-targeting therapies that focus on removing pathological proteins, neurotrophin and growth factor approaches enhance the brain's intrinsic capacity for neuronal survival, synaptic plasticity, and repair.
The rationale for this approach stems from the well-documented decline of neurotrophic support in Alzheimer's disease. Key growth factors including [BDNF](/proteins/bdnf-protein), [GDNF](/proteins/gdnf-protein), [NGF](/proteins/nerve-growth-factor), and [FGF](/proteins/fgf-protein) family members are reduced in AD brains, contributing to synaptic loss, neuronal death, and cognitive decline. By delivering or enhancing these neurotrophic signals, companies in this space aim to slow or reverse disease progression through disease-modifying mechanisms.
This category covers companies developing:
[Athira Pharma](/companies/athira-pharma) (NASDAQ: ATHA) is a clinical-stage company developing fosgonimeton (ATH-1017), a small molecule that targets the hepatocyte growth factor (HGF) system to promote neuroprotection, regeneration, and repair.
| Attribute | Details |
|-----------|---------|
| Lead Program | Fosgonimeton (ATH-1017) |
| Mechanism | HGF/MET receptor activator |
| Indication | Alzheimer's disease |
| Stage | Phase 2/3 |
| Status | Recruiting (ACT-AD study) |
Mechanism of Action: Fosgonimeton activates the MET receptor, which promotes neuronal survival, enhances synaptic function and plasticity, supports neurogenesis, modulates neuroinflammation, and improves cerebral blood flow. The HGF/MET system is naturally involved in brain repair mechanisms and is downregulated in Alzheimer's disease.
Clinical Development:
[Trefoil Therapeutics](/companies/trefoil-therapeutics) is a clinical-stage biotechnology company developing engineered neurotrophic factors with improved pharmacological properties.
| Attribute | Details |
|-----------|---------|
| Headquarters | Boston, Massachusetts |
| Founded | 2021 |
| Funding | Series B ($55M, 2024) |
| Focus | Engineered neurotrophic factors |
Pipeline:
| Drug | Mechanism | Indication | Stage |
|------|-----------|------------|-------|
| TF-201 | Synaptic growth factor | Alzheimer's disease | Phase 1 (recruiting) |
| TF-202 | Neuroprotective factor | Parkinson's disease | Preclinical |
TF-201 (Lead Candidate):
[Neurotrope BioScience](/companies/neurotrope) (NASDAQ: NTRP) is a clinical-stage biopharmaceutical company focused on developing bryostatin, a protein kinase C (PKC) activator, for Alzheimer's disease.
| Attribute | Details |
|-----------|---------|
| Lead Program | Bryostatin-1 |
| Mechanism | PKC epsilon activator |
| Indication | Alzheimer's disease |
| Stage | Phase 2 |
| Ticker | NTRP (NASDAQ) |
Mechanism of Action:
[Teitur Trophics](/companies/teitur-trophics) is a biotechnology company focused on developing neurotrophic factor therapies for neurodegenerative diseases.
| Attribute | Details |
|-----------|---------|
| Focus | Neurotrophic factors, AD, PD |
| Stage | Preclinical/Discovery |
| Status | Private |
Pipeline:
| Drug | Mechanism | Indication | Stage |
|------|-----------|------------|-------|
| TT-101 | BDNF receptor agonist | Alzheimer's disease | Preclinical |
| TT-102 | GDNF analog | Parkinson's disease | Discovery |
| TT-103 | Neuroprotective peptide | Neurodegeneration | Discovery |
TT-101 (BDNF Receptor Agonist):
[Synaptic Therapeutics](/companies/synaptic-therapeutics) is a clinical-stage biotechnology company focused on protecting and restoring synaptic function in neurodegenerative diseases.
| Attribute | Details |
|-----------|---------|
| Headquarters | Cambridge, Massachusetts |
| Founded | 2021 |
| Funding | Series B ($60M, 2025) |
Pipeline:
| Drug | Mechanism | Indication | Stage |
|------|-----------|------------|-------|
| ST-101 | Sigma-2 receptor agonist | Alzheimer's disease | Phase 1 (active) |
| ST-202 | Sigma-2 receptor agonist | Parkinson's disease | Preclinical |
Mechanism: While not a direct neurotrophin, ST-101 protects synapses through sigma-2 receptor modulation, which activates stress protective pathways and prevents amyloid-beta induced synapse damage. The company focuses on downstream synaptic protection rather than upstream amyloid reduction.
| Company | Program | Mechanism | Stage |
|---------|---------|-----------|-------|
| AbbVie | -- | TrkB agonist | Preclinical |
| Takeda | -- | GDNF analog | Preclinical |
| Lilly | -- | Neurotrophic modulators | Discovery |
Neurotrophins (BDNF, NGF, NT-3, NT-4) signal through Trk receptor family. Small molecule agonists aim to activate these receptors without the delivery challenges of protein therapeutics.
| Target | Function | Companies |
|--------|----------|-----------|
| TrkB | BDNF receptor | Teitur Trophics, AbbVie |
| TrkA | NGF receptor | Various |
| TrkC | NT-3 receptor | Research stage |
The GDNF family (GDNF, neurturin, artemin, persephin) signals through GFRα/Ret receptor complex and is particularly important for neuronal survival.
| Factor | Target | Companies |
|--------|--------|-----------|
| GDNF | GFRα1/Ret | Takeda, various |
| Neurturin | GFRα2/Ret | Previous trials |
Hepatocyte growth factor signals through the MET receptor, promoting neuroprotection and synaptic plasticity.
| Target | Companies | Stage |
|--------|-----------|-------|
| HGF/MET | Athira Pharma | Phase 2/3 |
Fibroblast growth factors promote neurogenesis and synaptic plasticity. Engineered variants aim to improve pharmacological properties.
| Company | Program | Stage |
|---------|---------|-------|
| Trefoil Therapeutics | TF-201 | Phase 1 |
| Various | FGF analogs | Preclinical |
Protein kinase C activation promotes synaptic plasticity and neurotrophic factor expression.
| Company | Compound | Stage |
|---------|----------|-------|
| Neurotrope | Bryostatin | Phase 2 |
| Company | Drug | Phase | Mechanism | NCT Number |
|---------|------|-------|-----------|------------|
| Athira Pharma | Fosgonimeton | Phase 2/3 | HGF/Met | NCT04466921 |
| Trefoil Therapeutics | TF-201 | Phase 1 | FGF variant | TBD |
| Neurotrope | Bryostatin | Phase 2 | PKC activator | NCT04594060 |
| Synaptic Therapeutics | ST-101 | Phase 1 | Sigma-2 | TBD |
The primary challenge for growth factor therapy is delivering sufficient concentrations to the CNS. Current approaches include:
| Strategy | Description | Companies |
|----------|-------------|-----------|
| AAV gene therapy | Viral vector-mediated expression | Various |
| Focused ultrasound | Temporary BBB opening | Research |
| Small molecule agonists | BBB-penetrant compounds | Athira, Teitur |
| Encapsulated cells | Cell-based delivery | Research |
| Approach | Advantages | Challenges |
|----------|------------|-----------|
| Protein delivery | Native sequence, high potency | BBB penetration, stability |
| Gene therapy | Sustained expression | Immune response, delivery |
| Small molecules | BBB penetration, oral dosing | Receptor selectivity |
Multiple neurotrophic systems are impaired in Alzheimer's disease:
Growth factors provide neuroprotection through:
| Approach | Mechanism | Administration | ARIA Risk |
|----------|-----------|---------------|-----------|
| Lecanemab | Anti-amyloid antibody | IV infusion | Yes |
| Donanemab | Anti-amyloid antibody | IV infusion | Yes |
| Fosgonimeton | HGF/MET agonist | Oral | No |
| Bryostatin | PKC activator | IV | No |