Combining Delivery Routes for a More Effective Gene Therapy for Infantile NCL

1. Combining Delivery Routes for a More Effective
Gene Therapy For Infantile NCL
Alejandra J. Rozenberg1, Erik A. Lykken2, Steven J. Gray2
1Gene Therapy, University of North Carolina at Chapel Hill, Chapel Hill, NC;
2 Pediatrics, University of Texas Southwestern Medical Center, Dallas, TX
l
Contact :Steven.Gray@UTSouthwestern.edu
CLN1
BDSRA 2018
III. Intrathecal injection (lumbar
puncture)
Vector will flow through the
cerebrospinal fluid and distribute
throughout the CNS.
Used for the CLN6 and Giant Axonal
Neuropathy (GAN) clinical trials.
I. Direct brain injection
A. The vector is injected into multiple areas of the
brain. Approach of the CLN2 clinical trial with AAV.
B. Vector can be injected into the cerebrospinal fluid
(CSF) that surrounds and runs through the brain and
spinal cord (into ventricles or into the cisterna magna).
II. Intravenous injection
Uses a vector that can reach the brain by
crossing the Blood-Brain barrier.
Utilized in Spinal Muscular Atrophy (SMA)
and MPS IIIA clinical trials.
Getting the vector to the brain
There are three main delivery routes:
Cerebrospinal
fluid
Brain
Spinal
Cord
— Each form of Batten (Neuronal Ceroid Lipofuscinoses -
NCL-) is caused by a mutation in the patient’s DNA that
renders a gene defective.
— Gene transfer is the idea of replacing the defective
gene with a working copy of the gene.
What is gene therapy?
— Gene transfer should correct the disease at the source
of the problem, rather than just treating symptoms.
— “Gene transfer” becomes gene therapy when the new
gene fixes some aspect of the disease and it helps the
patient.
— Since the gene is corrected, one treatment can be a
permanent fix.
— The new healthy copy of the
gene has to be delivered to
the cells. Anything that is used
to move the DNA into the cells
is called a vector.
— The most prominent and
widely used vector for
Batten Disease and other
brain disorders is the
Adeno-Associated Virus
(AAV).
Used in over 75 human
clinical trials, including
Parkinson’s, Batten and
Canavan Disease.
How does gene transfer work?
cell makes protein
using new gene
— Our results support a rationale for dosing patients by both routes
simultaneously.
— Our preliminary results in mice also suggest the possibility of treating
moderately affected patients.
Gene Therapy in INCL mice
Conclusions
Other NCL efforts in the Gray Lab
— CLN2: testing gene therapy in a mouse model.
— CLN7: testing gene therapy in a mouse model.
— CLN5 and CLN6: collaboration with David Palmer in New Zealand, in sheep
models.
Cell with
defective gene
Introduction of
healthy gene
Cell function
restored
Contributors at UNC
Courtney Santos
Khushnood Faraz
UNC Vector Core
UNC Mouse Behavioral
Phenotyping Core
Collaborators
Mark Sands (WashU)
Jonathan Cooper (UCLA)
Sandra Hofmann (UTSW)
Symptoms
Low Dose
High Dose
Untreated
INCL mice
1 week-IT
4 week-IT
12 week-IT
20 week-IT
26 week-IT
Untreated
normal mice
lifespan
20 week
Dual-route
treatment
In progress
Age at time of
intervention-route
Treatment comparison in mice
LD (Low Dose)
HD (High Dose)
Experimental design:
single time point treatment
IT: Intrathecal (lumbar puncture)
IV: Intravenous (tail vein)
IT HD
6 months 8 months3 months
IT HD
1 month1 weekBirth
4.5 months
IT LD
pre-symptomatic early-symptomatic symptomatic premature death
✾IT HD + IV HD
Combination
therapy:
Results with intrathecal route
— While mice treated at a later stage in the disease with
the lower dose did not show any significant benefits,
treatment with this same dose extended lifespan and
improved behavior for mice at earlier stages.
— Treatment with a higher dose provided significant
benefits in the early-symptomatic mice and greatly
improved outcomes for younger mice.
— We established that 1) early treatment is better; and
2) higher dose is better.
— Although treating earlier is better, without newborn screening, the
majority of INCL patients in the near future will be treated at the
early-symptomatic or symptomatic stages.
Intrathecal and intravenous dual
treatment: Why combine both?
— The IT dose is limited by the volume that can be safely
injected into the intrathecal space. By combining it with an
intravenous (IV) dose, we hypothesized that it could further
improve survival and behavior in early-symptomatic mice.
Results with combination therapy
— The dual treatment provided significant benefits in behavior
and survival over the intrathecal route alone in early-
symptomatic mice.
— We continue evaluating this cohort (with some of them
currently reaching 16.3 months of age).
— We are further exploring combination treatment in younger mice.
IT HD
IT LD
IT HD
IT LDIT HD
IT LD