This category covers biotechnology and pharmaceutical companies developing therapeutics that target retromer dysfunction and endosomal trafficking impairments in Alzheimer's disease. The retromer complex — comprising VPS35, VPS26, and VPS29 — is a critical regulator of protein trafficking between endosomes and the Golgi apparatus or plasma membrane. Genetic studies have identified the VPS35 p.D620N mutation as a risk factor for familial Parkinson's disease, and retromer dysfunction is increasingly recognized as a contributor to amyloid-beta and tau pathology in AD[@mcgough2017].
Endosomal trafficking deficits are among the earliest cellular abnormalities in Alzheimer's disease, preceding clinical symptoms by decades. Impaired retrograde transport from endosomes to the Golgi disrupts amyloid precursor protein (APP) processing, leading to increased amyloid-beta production. Additionally, endosomal dysfunction contributes to tau propagation through extracellular vesicle-mediated spread.
- Ticker: ATH (ASX)
- Focus: Small molecule VPS35 modulators
- Lead Candidate: ATH-1105 (preclinical)
- Indication: Alzheimer's disease, Parkinson's disease
- Mechanism: Modulates retromer complex function to restore proper endosomal trafficking
- Science: Alterity's platform targets the retromer cargo recognition complex, enhancing the trafficking of proteins involved in APP processing and reducing amyloidogenic cleavage products
- Page: Alterity Therapeutics
- Focus: AAV-vectorized GBA1 gene delivery
- Lead Candidate: PR-001 (AAV-GBA1)
- Indication: Parkinson's disease (with GBA1 mutations), potentially AD
- Stage: Phase 1/2
- Mechanism: Delivers functional glucocerebrosidase (GCase) gene to enhance lysosomal function and endosomal trafficking
- Note: While primarily focused on PD, GBA1 therapy has implications for AD due to the shared lysosomal-endosomal pathway dysfunction
- Page: Prevail Therapeutics
- Focus: Glucocerebrosidase (GCase) modulators
- Lead Candidate: VQVN-001
- Indication: Parkinson's disease, Alzheimer's disease
- Stage: Preclinical
- Mechanism: Small molecule GCase chaperones to enhance enzymatic activity and reduce glycosphingolipid accumulation in lysosomes and endosomes
- Page: Vanqua Bio
- Focus: Allosteric GCase modulators
- Lead Candidate: GT-02287
- Indication: Alzheimer's disease (preclinical), Parkinson's disease (Phase 1b)
- Mechanism: Site-directed excipient engineering creates allosteric chaperones that stabilize misfolded GCase, enhancing lysosomal enzyme activity
- Platform: SEE-Tx (Site-Directed Excipient Engineering for Therapeutic molecules)
- Page: Gain Therapeutics
- Focus: LRRK2 inhibitors and endosomal trafficking modulators
- Lead Candidates: DNL151 (LRRK2 inhibitor), DNL310 (transport vehicle platform)
- Indication: Parkinson's disease, Alzheimer's disease
- Stage: Phase 1/2
- Mechanism: LRRK2 inhibition normalizes lysosomal and endosomal function; Transport Vehicle platform enables CNS delivery of therapeutic proteins
- Page: Denali Therapeutics
| Company |
Focus |
Mechanism |
Stage |
| Lysoway Therapeutics |
Lysosomal enzyme modulators |
GCase modulation, autophagy enhancement |
Discovery |
| Iduna Therapeutics |
Chaperone modulators |
Proteostasis restoration |
Preclinical |
| Pheast Therapeutics |
Endolysosomal targeting |
pH-gated drug delivery platform |
Discovery |
| Caraway Therapeutics |
TFEB activators |
Autophagy-lysosome pathway enhancement |
Preclinical |
flowchart TD
A["VPS35/VPS26 Mutations or Downregulation"] --> B["Retromer Complex Impairment"]
B --> C["Impaired Endosome-to-Golgi Retrograde Transport"]
C --> D["Altered APP Processing"]
D --> E["Increased Amyloid-beta Production"]
E --> F["Aβ Plaque Deposition"]
C --> G["Impaired BACE1 Trafficking"]
G --> E
C --> H["Tau Endosomal Spread"]
H --> I["Tau Pathology Propagation"]
F --> J["Synaptic Dysfunction"]
I --> J
J --> K["Cognitive Decline"]
- VPS35 Modulation: Small molecules that stabilize the retromer complex and enhance its cargo sorting function
- GBA1 Gene Therapy: AAV-mediated delivery of functional GBA1 to enhance lysosomal and endosomal function
- GCase Chaperones: Allosteric modulators that stabilize misfolded GCase and enhance enzymatic activity
- LRRK2 Inhibition: Kinase inhibitors that normalize endosomal trafficking dynamics
- TFEB Activation: Transcription factor activation to enhance lysosomal biogenesis
¶ Retromer and AD Pathogenesis
The retromer complex plays a critical role in maintaining proper endosomal sorting. In AD:
- VPS35 expression is reduced in AD brain tissue
- Retromer dysfunction leads to increased amyloidogenic APP processing
- Impaired retrograde transport contributes to endosomal compartment enlargement
- The retromer-Cargo receptor interaction is a potential therapeutic target
¶ Endosomal Trafficking and Tau Propagation
Endosomes serve as vehicles for tau propagation between neurons:
- Tau is internalized via endocytosis
- Endosomal trafficking facilitates trans-synaptic spread
- Impaired trafficking leads to intracellular tau accumulation
- Therapeutic approaches aim to normalize endosomal function
- McGough et al., Retromer stability and dysfunction in neurodegeneration (2017)
- VPS35 and retromer in Alzheimer's disease - Nature Reviews Neurology
- Endosomal trafficking dysfunction in AD - Nature Reviews Neuroscience