Encoded Therapeutics

Encoded Therapeutics, Inc. is a private biotechnology company headquartered in South San Francisco, California, developing gene therapies that use CRISPR-based activation to increase expression of disease-implicated genes for the treatment of severe neurological disorders. The company's lead program, ETX101, uses AAV-mediated CRISPRa to upregulate [SCN1A](/genes/scn1a) for the treatment of [Dravet syndrome](/diseases/dravet-syndrome)[@encoded2024].

Overview

Encoded Therapeutics, Inc. is a private biotechnology company headquartered in South San Francisco, California, developing gene therapies that use CRISPR-based activation to increase expression of disease-implicated genes for the treatment of severe neurological disorders. The company's lead program, ETX101, uses AAV-mediated CRISPRa to upregulate [SCN1A](/genes/scn1a) for the treatment of [Dravet syndrome](/diseases/dravet-syndrome)[@encoded2024].

Overview

Encoded's platform is built on the insight that many neurological diseases are caused by loss-of-function mutations where one allele is completely non-functional while the other remains intact. Rather than delivering a corrective gene, Encoded uses AAV-delivered CRISPR activation machinery to boost expression of the wild-type allele — essentially amplifying the body's existing backup capacity["@etx101mech"].

This approach contrasts with traditional gene therapy (which delivers a functional copy of the gene) and with ASO approaches (which are non-viral and require repeat dosing). AAV-mediated CRISPRa offers the potential for long-lasting, single-dose treatment with cell-type specificity["?"].

Platform Technology: CRISPR Gene Activation

Mechanism

Encoded's platform uses AAV-delivered CRISPR activation (CRISPRa) to increase transcription of target genes:

Key Advantages

• Single-dose potential: AAV provides durable expression of activation machinery
• Cell-type specificity: AAV serotype and promoter choice enable targeting of specific neuronal populations
• Non-cutting: dCas9 does not create double-strand breaks, reducing genotoxicity risk
• Allele-nonspecific: Can activate both alleles, but designed to preferentially enhance expression where beneficial

Comparison to ASOs (Stoke TANGO)

| Factor | Encoded CRISPRa (ETX101) | Stoke TANGO (STK-001) |
|--------|--------------------------|----------------------|
| Delivery | AAV (one-time) | ASO (repeat dosing) |
| Duration | Potentially lifelong | Requires quarterly dosing |
| Cell targeting | Engineered serotype/promoter | Broad CNS distribution |
| Regulatory precedent | AAV gene therapy precedent | ASO precedent (Spinraza, etc.) |
| Stage | Phase 1 | Phase 2 |
| Immunogenicity risk | AAV antibodies | Minimal |
| Manufacturing | AAV GMP complex | ASO GMP established |

Pipeline

ETX101 (Dravet Syndrome)

ETX101 is an AAV9-based CRISPR gene activation therapy designed to increase [SCN1A](/genes/scn1a) expression in inhibitory GABAergic interneurons — the specific cell type where loss of [SCN1A](/genes/scn1a) causes Dravet syndrome pathophysiology[@encoded2024].

Mechanism:

• AAV9 delivery of dCas9-VP64 activator
• Single intrathecal or intracisternal administration
• Increases SCN1A transcription in target neurons
• Provides durable, potentially lifelong expression

• LAYLA study (Phase 1): First-in-human dose escalation in patients with Dravet syndrome due to SCN1A haploinsufficiency
• IND-enabling completed: Successful IND filing with FDA
• Patient dosing initiated: 2024/2025

• Phase 1 LAYLA study ongoing
• Dose escalation cohort data accumulating
• Regulatory engagement with FDA for Phase 2 path
• Manufacturing scale-up for late-stage development

• Single-dose administration vs. quarterly injections
• Cell-type specificity for GABAergic interneurons
• Potentially permanent correction vs. transient effects

Additional Programs

Encoded has indicated pipeline expansion plans targeting:

• CDKL5 deficiency: CRISPRa approach for CDKL5 upregulation (preclinical)
• Additional genetic epilepsies: Platform expansion (discovery)

Funding History

| Round | Amount | Year | Purpose |
|-------|--------|------|---------|
| Series A | $30M | 2019 | Platform development, founding |
| Series B | $70M | 2021 | ETX101 IND-enabling, platform expansion |
| Series C | $135M | 2023 | Phase 1 initiation, manufacturing |
| Series D | $80M | 2025 | ETX101 Phase 1 continuation, manufacturing scale-up |

Total raised: ~$315M (one of the best-funded private gene therapy companies in neurological diseases)

Investors: Top-tier life science investors including RA Capital, Versant Ventures, Foresite Capital, and others[@encodedserd].

Financial and Corporate Status (March 2026)

| Metric | Value |
|--------|-------|
| Status | Private |
| Headquarters | South San Francisco, California |
| Founded | 2019 |
| Total Funding | ~$315M |
| Employees | ~100-150 |
| Valuation | Not publicly disclosed; estimated $500M-1B based on financing rounds |
| Last Round | Series D, $80M (2025) |

Competitive Position

Encoded competes in the Dravet syndrome landscape with:

| Competitor | Approach | Stage |
|-----------|----------|-------|
| [Stoke Therapeutics](/companies/stoke-therapeutics) (STOK) | ASO TANGO (STK-001) | Phase 2, FDA BTD |
| [Ultragenyx](/companies/ultragenyx) (GeneTx) | ASO for Angelman | Phase 2 |
| Roche/Neurocrine | AAV gene therapy | IND-enabling |

Competitive advantages:

• Single-dose AAV approach vs. repeat ASO dosing
• Cell-type specificity for interneurons
• Well-funded with $315M total
• Experienced leadership team in gene therapy and neurology

• Earlier stage than Stoke (Phase 1 vs. Phase 2)
• AAV regulatory path less established than ASOs
• Manufacturing scale-up for AAV complex
• CRISPRa novel mechanism with uncertain long-term expression durability

Scientific Advisory Board and Collaborations

Encoded maintains collaborations with leading neuroscience and gene therapy researchers:

• Academic partnerships for preclinical validation
• KOL engagement for clinical trial design
• Manufacturing partnerships for GMP supply

Key Publications

Hub Page Cross-Links

• [AAV Gene Therapy for Neurodevelopmental Epilepsy — Hub](/therapeutics/aav-gene-therapy-neurodevelopmental-epilepsy)](/therapeutics)
• [Dravet Syndrome Disease Page](/diseases/dravet-syndrome)](/diseases/dravet-syndrome)
• [SCN1A Gene Page](/genes/scn1a)](/genes)
• [ETX101 Clinical Trial Page](/clinical-trials/etx101-encoded-therapeutics-dravet-syndrome)](/therapeutics)
• [Stoke Therapeutics](/companies/stoke-therapeutics)