Vigonvita Therapeutics is developing an AAV-based gene therapy for CDKL5 deficiency disorder (CDD), a rare X-linked neurodevelopmental epilepsy caused by pathogenic variants in the CDKL5 gene. This preclinical program represents one of the most advanced industry-sponsored efforts to develop a CDKL5-directed gene therapy. The company is currently in IND-enabling studies with the goal of entering clinical trials in the near future.
| Parameter |
Value |
| Sponsor |
Vigonvita Therapeutics |
| Indication |
CDKL5 deficiency disorder (CDD) |
| Modality |
AAV gene therapy |
| Vector |
AAV9 (pending confirmation) |
| Development Stage |
Preclinical / IND-enabling |
| Delivery Route |
To be determined (likely ICV or ICM) |
| Target Population |
Pediatric patients (ages 2+) |
CDKL5 deficiency disorder (CDD) is a devastating neurodevelopmental disorder characterized by:
- Onset: Early infancy (3-12 months), often before 6 months of age
- Seizure types: Multiple types including infantile spasms, focal seizures, myoclonic seizures, tonic-clonic seizures
- Seizure pattern: Often refractory to anti-seizure medications
- Developmental outcome: Severe intellectual disability, limited or absent speech, gross motor impairment
- Core features: Classic Rett-like phenotype with autistic features, movement disorders
- Gene: CDKL5 (cyclin-dependent kinase-like 5), located on chromosome Xp22.13
- Inheritance: X-linked dominant, predominantly affecting females
- Male lethality: Most males with pathogenic CDKL5 variants do not survive gestation or die shortly after birth
- Variant types: Missense, nonsense, frameshift, splice site, and large deletions
- Gene size: ~1.5kb coding sequence — fits well within AAV capacity
- Prevalence: Approximately 1 in 40,000-80,000 live births
- Gender distribution: Overwhelmingly female (approximately 90%)
- Family history: Usually sporadic, though inherited cases documented
Vigonvita's approach uses AAV-mediated delivery of a functional CDKL5 transgene to restore normal CDKL5 protein expression in the central nervous system:
- Vector: Recombinant AAV9 (or engineered capsid)
- Promoter: Neuron-specific promoter for targeted expression
- Transgene: Full-length human CDKL5 coding sequence
- Delivery: Stereotactic injection or CSF-delivered (ICV/ICM)
- CDKL5 is a kinase critical for neuronal development and function
- Loss-of-function variants cause the characteristic phenotype
- Early intervention may prevent or reduce developmental regression
- Gene replacement aims to restore physiological levels of CDKL5
| Finding |
Relevance |
| CDKL5 expression restored in neurons |
Proof-of-concept for gene replacement |
| Dose-dependent expression levels |
Supports dose-selection for IND |
| Motor behavior improvements in mouse models |
Functional benefit observed |
| No off-target toxicity |
Safety profile supports advancement |
- Mouse models: Cdkl5 knockout and humanized mouse models
- Endpoints evaluated: Expression, motor function, seizure frequency, survival
¶ Remaining Preclinical Work
- Long-term biodistribution studies
- GLP toxicity studies
- Manufacturing scale-up for clinical supply
¶ Competitive Landscape
| Company/Group |
Approach |
Stage |
Status |
| Vigonvita Therapeutics |
AAV-CDKL5 |
Preclinical |
IND-enabling |
| Ultragenyx |
AAV-CDKL5 (exploratory) |
Preclinical |
Research |
| Academic groups (multiple) |
AAV-CDKL5 |
Research |
Active |
| Roche |
Small molecule |
Discovery |
Preclinical |
| Feature |
CDKL5 (Vigonvita) |
Dravet (STK-001) |
Angelman (GTX-102) |
| Modality |
AAV gene therapy |
ASO |
ASO |
| Target |
CDKL5 |
SCN1A |
UBE3A-ATS |
| Stage |
Preclinical |
Phase 1/2 |
Phase 1/2 |
| Route |
TBD |
Intrathecal |
Intrathecal |
| Gene size |
~1.5kb |
N/A |
N/A |
| Milestone |
Expected Timing |
| IND-enabling studies complete |
2025-2026 |
| IND filing |
2026 |
| Phase 1/2 initiation |
2026-2027 |
| Early efficacy data |
2027-2028 |
| Risk Factor |
Mitigation |
| Manufacturing scale-up |
EarlyCMC engagement |
| Delivery optimization |
Non-human primate studies |
| Phenotypic variability |
Biomarker development |
| Female-only population |
Enrollment strategy |
- Expected: Yes, CDKL5 deficiency qualifies as rare disease
- Benefits: 10-year market exclusivity (US), protocol assistance
- Expected: Yes, if approvable
- Benefits: Priority review voucher (transferable)
- May qualify for: Breakthrough Therapy Designation, RMAT designation
- Rationale: Severe disease, unmet need, genetic etiology