Experiment Category: Gene Therapy / IND-Enabling Preclinical Studies
Created: 2026-03-21
Based on: AAV Serotype Comparison for LRRK2 (/experiments/aaav-serotype-comparison-lrrk2)
This document outlines comprehensive IND-enabling preclinical studies for AAV-LRRK2 gene therapy targeting Parkinson's disease. Building on our serotype comparison results demonstrating AAV-PHP.B as the optimal vector, we propose a complete package including GLP toxicology, biodistribution, dose escalation, and long-term NHP safety studies to support an IND submission to the FDA.
¶ Background and Rationale
LRRK2 (Leucine-Rich Repeat Kinase 2) mutations are the most common cause of autosomal-dominant Parkinson's disease, accounting for 5-10% of familial PD cases. Our prior serotype comparison study identified AAV-PHP.B as demonstrating superior transduction efficiency and reduced immunogenicity compared to traditional serotypes (AAV2, AAV5, AAV9) in both mouse and NHP brain tissue.
The IND-enabling studies outlined below are designed to generate the safety, toxicity, and efficacy data required by FDA 21 CFR 312.23 for a gene therapy IND application.
- Evaluate the safety and tolerability of a single intracerebral dose of AAV-PHP.B-shLRRK2 in rats and non-human primates
- Identify target organs, dose-limiting toxicities, and maximum tolerated dose (MTD)
- Generate GLP-compliant data for IND submission
| Parameter |
Rats |
Non-Human Primates |
| Species |
Sprague-Dawley |
Cynomolgus macaques |
| Age |
8-10 weeks |
3-5 years |
| Groups |
4 (3 dose + 1 control) |
4 (3 dose + 1 control) |
| Males/Females |
10/sex/group |
3/sex/group |
| Doses |
Low: 1×10^13 GC, Mid: 3×10^13 GC, High: 1×10^14 GC |
Low: 1×10^13 GC, Mid: 3×10^13 GC, High: 1×10^14 GC |
| Route |
Intracerebral (stereotactic) |
Intracerebral (stereotactic) |
| Observation |
28 days |
90 days |
- Clinical observations (neurological, behavioral, physical)
- Body weight and food consumption
- Clinical pathology (hematology, clinical chemistry, coagulation)
- Gross necropsy and organ weights
- Histopathology (including brain, liver, kidney, spleen, heart, lung)
- Immunogenicity (anti-AAV antibodies, T-cell responses)
- Biodistribution (qPCR for vector genome copy number)
- LRRK2 mRNA expression in target tissues
- Biomarker analysis (NfL, tau, α-synuclein in CSF)
- Cytokine/chemokine panels
| Item |
Cost |
| GLP study contract (CRO) |
$450,000 |
| Vector production (GLP grade) |
$120,000 |
| Histopathology |
$85,000 |
| Bioanalysis |
$65,000 |
| Report writing |
$35,000 |
| Total |
$755,000 |
- Determine vector genome distribution following intracerebral administration
- Identify off-target tissues and persistence
- Characterize shedding characteristics
| Parameter |
Mice |
NHPs |
| Species |
C57BL/6 |
Cynomolgus macaques |
| Groups |
5 timepoints |
3 timepoints |
| Timepoints |
1, 7, 28, 90, 180 days |
7, 90, 180 days |
| Tissues collected |
25 tissues |
30 tissues |
| Samples per timepoint |
10 animals |
3 animals |
- Brain (injected region, contralateral, cortex, cerebellum)
- Spinal cord
- Liver
- Spleen
- Kidney
- Heart
- Lung
- Testis/Ovary
- Drainage lymph nodes
- Blood (plasma, PBMCs)
- Droplet digital PCR (ddPCR) for vector genome quantification
- RNAseq for transcriptional changes
- ELISA for protein expression
| Item |
Cost |
| Vector production |
$50,000 |
| Tissue processing |
$35,000 |
| ddPCR analysis |
$45,000 |
| RNAseq |
$30,000 |
| Report |
$15,000 |
| Total |
$175,000 |
- Establish dose-response relationship for efficacy
- Identify no-observed-adverse-effect level (NOAEL)
- Support dose selection for pivotal studies
| Parameter |
Rats |
| Groups |
5 (4 dose + 1 vehicle) |
| Dose range |
1×10^11 to 1×10^14 GC |
| Route |
Intracerebral |
| Duration |
90 days |
| Animals |
15/sex/group |
- LRRK2 mRNA knockdown (qPCR)
- LRRK2 protein expression (Western blot, IHC)
- Tyrosine hydroxylase (TH) neuron survival
- Behavioral testing (cylinder, rotarod, gait analysis)
- Neuroinflammation markers (Iba1, GFAP)
| Item |
Cost |
| Vector production |
$80,000 |
| In-life phase |
$95,000 |
| Tissue analysis |
$55,000 |
| Behavioral testing |
$25,000 |
| Report |
$20,000 |
| Total |
$275,000 |
- Evaluate safety of long-term LRRK2 knockdown
- Assess durability of therapeutic effect
- Characterize late-onset toxicity (12 months)
| Parameter |
Specification |
| Species |
Cynomolgus macaques |
| Groups |
4 (3 dose + 1 control) |
| Doses |
Low: 1×10^13 GC, Mid: 3×10^13 GC, High: 1×10^13 GC |
| Animals |
6/sex/group (48 total) |
| Duration |
12 months |
| Route |
Bilateral intraparenchymal (SNc + striatum) |
- Monthly neurological examinations
- Quarterly CSF collection (cell count, protein, NfL, tau, α-syn)
- PET imaging (DAT, TH) at baseline, 6, 12 months
- Comprehensive behavioral assessment
- Full neural axis examination
- Peripheral organ toxicity
- Reproductive organ assessment
- Electron microscopy of target neurons
| Item |
Cost |
| NHP procurement & holding |
$720,000 |
| Vector production |
$180,000 |
| In-life monitoring |
$250,000 |
| Imaging (PET) |
$120,000 |
| CSF analysis |
$85,000 |
| Histopathology |
$150,000 |
| Bioanalysis |
$75,000 |
| Report writing |
$60,000 |
| Total |
$1,640,000 |
- Production scale: 1-5 × 10^14 GC per batch
- System: Triple transfection in HEK293 cells
- Purification: CsCl gradient or affinity chromatography
- Production scale: 1-5 × 10^16 GC per batch
- Scale-up pathway:
| Phase |
Scale |
Timeline |
Purpose |
| Pilot |
10^15 GC |
Months 1-3 |
Process development |
| Demo |
5×10^15 GC |
Months 4-6 |
Validation batches |
| GMP Batch 1 |
1×10^16 GC |
Months 7-9 |
GLP toxicology |
| GMP Batch 2 |
1×10^16 GC |
Months 10-12 |
Pivotal studies |
| GMP Batch 3 |
1×10^16 GC |
Months 13-15 |
IND filing |
| Company |
Location |
Capability |
| Vigene Biosciences |
USA (MD) |
AAV GMP, 200L+ |
| Catalent |
USA (NJ) |
AAV GMP, 1000L |
| Oxford BioMedica |
UK |
Lentivirus/AAV GMP |
| Thermo Fisher |
USA |
GMP manufacturing |
| Charles River Labs |
USA |
GLP/GMP toxicology |
| Requirement |
Specification |
| Identity |
Sequencing, restriction analysis |
| Purity |
>95% empty capsids,  % host cell DNA |
| Potency |
Transduction units (TU) per mL |
| Stability |
24 months at -80°C |
| Sterility |
No growth in sterility tests |
| Endotoxin |
<0.5 EU/mL |
| Item |
Cost |
| Process development |
$200,000 |
| GMP vector production (3 batches) |
$600,000 |
| Analytical testing |
$150,000 |
| Fill/finish |
$75,000 |
| Stability studies |
$100,000 |
| Quality release |
$50,000 |
| Total |
$1,175,000 |
- Product Type: Gene therapy (AAV vector)
- Route: Intracerebral (intraparenchymal)
- Classification: Biological, Section 351(a) (Live recombinant virus)
- FDA Division: Center for Biologics Evaluation and Research (CBER)
| Document |
Status |
Timeline |
| Product description |
To be prepared |
Month 1-2 |
| Manufacturing summary |
To be prepared |
Month 1-3 |
| Preclinical data package |
To be prepared |
Month 3-6 |
| IND application |
To be filed |
Month 9 |
- Timing: Prior to IND submission
- Topics: Study design, CMC requirements, regulatory expectations
- FDA Office: Office of Cellular, Tissue, and Gene Therapies (OCTGT)
- Efficacy Endpoints: Discuss with FDA on appropriate biomarkers vs. clinical endpoints
- Animal Model Requirements: Demonstrate relevance to human disease
- Dose Selection: Provide scientific rationale based on NHP data
- Manufacturing Changes: Minimize between toxicology and clinical batches
- Risk Mitigation: Immune response management strategy
| Milestone |
Target Date |
| Pre-IND meeting |
Month 6 |
| IND submission |
Month 9 |
| IND clearance |
Month 12 |
| First patient dosing |
Month 15 |
| Item |
Cost |
| Regulatory consulting |
$75,000 |
| Pre-IND meeting preparation |
$25,000 |
| IND application assembly |
$35,000 |
| FDA user fees |
$2,478 (IND) |
| Post-IND support |
$50,000 |
| Total |
$187,478 |
gantt
title AAV-LRRK2 IND-Enabling Studies Timeline
dateFormat YYYY-MM
section Manufacturing
Process Development :2026-04, 3
GMP Production Batch 1 :2026-07, 3
GMP Production Batch 2 :2026-10, 3
GMP Production Batch 3 :2027-01, 3
section GLP Toxicology
Single-Dose Toxicology :2026-07, 6
Long-Term NHP Study :2026-10, 12
section Other Studies
Biodistribution :2026-07, 6
Dose-Range Finding :2026-07, 4
section Regulatory
Pre-IND Meeting :2026-09, 1
IND Submission :2026-12, 1
| Category |
Cost |
| GLP Toxicology |
$755,000 |
| Biodistribution |
$175,000 |
| Dose-Range Finding |
$275,000 |
| Long-Term NHP Safety |
$1,640,000 |
| Manufacturing |
$1,175,000 |
| Regulatory |
$187,000 |
| TOTAL |
$4,207,000 |
¶ Risk Assessment and Mitigation
| Risk |
Probability |
Impact |
Mitigation |
| NHP study delays |
Medium |
High |
Contingency timeline, alternative CRO |
| Manufacturing failure |
Low |
High |
Dual sourcing, process robustness |
| Regulatory hold |
Low |
High |
Pre-IND communication, robust data |
| Immune response |
Medium |
Medium |
Immunomodulation protocol |
| Efficacy signal weak |
Medium |
High |
Dose optimization, alternative constructs |
This comprehensive IND-enabling study package provides a clear path from our promising preclinical data to an FDA IND submission for AAV-LRRK2 gene therapy in Parkinson's disease. The total investment of approximately $4.2M over 15-18 months positions the program for clinical development with a well-characterized, safe, and effective gene therapy candidate.