Sitara Tx is developing neuroprotective astrocyte cell therapies to halt the progression of ALS and other neurodegenerative diseases — targeting the cells that orchestrate neuronal destruction.
The Problem
Neurodegenerative diseases like ALS, Alzheimer's, and Parkinson's aren't solely caused by neuronal death. Dysfunctional astrocytes actively accelerate the destruction of motor neurons.
While neurons are the casualties, astrocytes are the orchestrators of their demise. No curative treatment currently addresses this root driver.
The Biology
In health, astrocytes sustain neurons. In disease, they transform from protectors into executioners — releasing toxic factors, withdrawing support, and amplifying neuroinflammation.
Prevent excitotoxic motor neuron death by clearing excess glutamate from synaptic clefts. Dysfunctional astrocytes lose this capacity, leading to neuronal overactivation and death.
Maintain the protective barrier that shields neurons from circulating toxins and immune cells. Breakdown of this barrier is an early event in ALS pathology.
Phagocytose cellular waste — including toxic protein aggregates like TDP-43 — and prevent accumulation that disrupts neuronal function. TDP-43 aggregates are present in 97% of all ALS cases.
Sustain synaptic function, neuronal communication networks, and release neuroprotective factors (BDNF, GDNF) essential for motor neuron survival. Loss of this support accelerates degeneration.
Our Technology
Our DL4-bead platform mimics the precise mechanical cell-to-cell signaling required for astrocyte specification — engineered directly into the developmental window when astrocyte fate is determined. The result: neuroprotective astrocytes in ~2 months, versus 4–6 months for existing approaches.
Profiled the developing human brain to map gene expression during native astrocyte formation.
Identified a critical Notch signaling spike before astrocyte fate commitment — the precise moment to intervene.
Engineered DL4-coated microbeads that deliver this exact Notch signal to neural progenitor cells at day 14–21 of differentiation.
DL4-astrocytes show low A1 neurotoxic scores and moderate A2 neuroprotective scores — confirmed by scRNA-seq, flow cytometry, and functional assays.
DL4-astrocytes score low as A1 neurotoxic and moderately as A2 neuroprotective — validated by single-cell transcriptomics against primary fetal astrocytes.
~2 months versus the 4–6 months of competing approaches — critical when ALS median survival is only 30 months from symptom onset.
Off-the-shelf product from HLA-matched iPSC lines enables broad treatment access — with an autologous option to minimize immune rejection.
Platform architecture supports next-generation engineered astrocytes — correcting disease mutations or overexpressing protective factors like NRF2 and IL4.
International patent filed (WO2025231103, Arc Institute; inventors: Salvi & Konermann). Orphan Drug Designation eligible — 7-year US market exclusivity post-approval.
Programs
The DL4-bead astrocyte platform underpins four programs across CNS neurodegeneration — with ALS as the lead indication and a near-term drug screening revenue stream.
| Program | Indication | Target | Stage | Status |
|---|---|---|---|---|
| SIT-1 Lead Program |
ALS | Allogeneic Astrocytes |
|
Active |
| SIT-2 ALS Engineering |
ALS | Engineered Astrocytes |
|
Active Investigation |
| SIT-3 | Spinal Cord Injury | Allogeneic Astrocytes |
|
Pending SIT-1 IND |
| SIT-4 | Parkinson's Disease | Engineered Astrocytes |
|
Pending SIT-1 IND |
The Team
Sitara Tx was founded from Stanford and Arc Institute — at the intersection of stem cell biology, gene editing, and translational neuroscience.
Development Roadmap
Two parallel tracks — cell therapy toward the clinic, and a drug screening platform generating near-term non-dilutive revenue and validation data.
Patient iPSC co-culture validation; efficacy benchmarks in SOD1 and TDP-43 models. Drug screening revenue from DL4-astrocyte platform partnerships comes online, providing non-dilutive capital.
Safety pharmacology, biodistribution, and toxicology in rodent ALS models. Preparation for Orphan Drug and Fast Track Designation filings with the FDA.
Multi-line optimization, GMP process development, and cryopreservation validation for allogeneic manufacturing at clinical scale.
First-in-human dose escalation in ALS patients. Drug screening platform commercially active in parallel. ALSFRS-R slope at 6 months as primary endpoint.
Get in Touch
We are actively seeking seed investment, pharma partnerships, and academic collaborations to advance our astrocyte platform toward the clinic.