Single-dose extended-toxicity preclinical study on novel ...
Translating Preclinical Data to a Human Equivalent Dose ...
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Presented at the International Congress of Parkinson’s Disease and Movement Disorders ® Nice, France, September 22-26, 2019 BACKGROUND Huntington’s disease (HD) is a fatal neurodegenerative disorder caused by a CAG trinucleotide repeat expansion in the huntingtin (HTT) gene. The results of proof-of-concept studies in HD rodent models have been difficult to translate to humans because of significant differences in neuroanatomy and brain size. This is particularly relevant for gene therapy approaches, where distribution achieved upon local administration into the parenchyma is dependent on brain size and structure. 1 The gene-lowering therapy being developed by uniQure is based on the next-generation miQURE™ technology targeting huntingtin mRNA. 2 The DNA expression cassette encoding the mi HTT is delivered using recombinant adeno-associated viral vector serotype 5 (rAAV5-miHTT; AMT-130) (Figure 1). Figure 1. Mechanism of action of AMT-130 1. Upon one-time intracranial parenchymal injection of AMT-130, rAAV5- miHTT binds to neuronal cell-surface receptors and is internalized. 2. Transport to the nucleus and uncoating of the miHTT transgene which remains mostly episomal. 3. Expression and processing of the miHTT transgene by the endogenous RNA interference machinery. 4. Hairpin structured precursor is transported to the cytoplasm and further processed to mature guide miHTT. No passenger strand is formed, strongly limiting the risk of off-target activity. 5. Mature miHTT is loaded in the RNA-induced silencing complex and binds to HTT mRNA. 6. HTT mRNA is cleaved and degraded, resulting in lowering of huntingtin protein translation. HTT, huntingtin; miHTT, microRNA targeting human HTT. Preclinical data in HD animal models shows that lowering aberrant HTT mRNA and mutant (mut) HTT protein species by AMT-130 ameliorates the molecular, neuropathological, metabolic, and clinical phenotype in HD. 3-5 Good laboratory practice (GLP) toxicology and safety studies in non-human primates (NHPs) have shown excellent tolerability and safety after a single administration of AMT-130 by intraparenchymal convection-enhanced delivery to the striatum. OBJECTIVE ■ To determine the human equivalent dose (HED) of AMT-130 to lower HTT RNA and mutHTT protein in the brains of adults with early manifest HD. METHODS ■ Volumetric magnetic resonance imaging (MRI) was performed on 19 patients from the outpatient neurological clinic. ■ T1- and T2-weighted MRI images with contrast were reconstructed and processed using in-house software to determine putamen and caudate nucleus volumes. ■ T2 volumes were used to estimate the volume of perivascular spaces in each putamen. ■ AMT-130 was administered bilaterally to the caudate nucleus and putamen in NHPs using real-time, MRI-guided convection-enhanced delivery (CED). ■ Real-time volume of distribution (Vd) and volume of infusion (Vi) data from NHPs were used to estimate a scale-up factor for the AMT-130 HED. ■ The HED to lower mutHTT was extrapolated using a regression plot based on the brain biodistribution in small and large HD transgenic models. RESULTS Striatal volume was analyzed in 19 MRI scans: ■ The mean putamen and caudate volumes in adult patients with early manifest HD were 3.11 cm 3 and 2.24 cm 3 , respectively (Table 1). Table 1. Striatal volumes in healthy adults, adults with early manifest HD, and NHPs Brain structure Mean ± SD volume (cm 3 ) per hemisphere Healthy adults 6 Early manifest HD (n = 19) Healthy NHPs (n = 22) 6 Putamen 3.57 ± 0.17 3.11 ± 0.54 0.55 ± 0.01 Caudate 2.73 ± 0.06 2.24 ± 0.36 0.41 ± 0.02 Striatum 6.33 ± 0.44 5.17 ± 0.88 0.97 ± 0.04 cm 3 , cubic centimeters; HD, Huntington’s disease; NHPs, non-human primates; SD, standard deviation. ■ Striatal volumes in HD were approximately 13% (putamen) and 18% (caudate) less than those typically observed in healthy adults 6 (Figure 2). Figure 2. Sagittal 3T volumetric MRI scans showing progressive brain atrophy in adults with early manifest HD Control Pre-manifest HD Early manifest (Stage 1/2 HD) ~30% striatal atrophy; 10% decrease in total brain volume Modified from Tabrizi SJ, et al. 7 Volumes are corrected for intracranial volume. HD, Huntington’s disease; MRI, magnetic resonance imaging. The infusion parameters for MRI-guided CED of AMT-130 in humans per hemisphere was based on the following: ■ 200 μL filled ~50% of the NHP striatum 6 with a V d /V i ratio of 2.0. ■ A conversion factor of 5.3 was calculated based on the striatal volumes in adult patients with early manifest HD to achieve the same degree of AMT-130 filling in humans. ■ A V d /V i ratio of 2.0 and an infusion volume of 1.50 mL per striatum is predicted to fill ~50% of the structure. ■ The putamen will be infused twice with 0.50 mL and the caudate once with 0.5 mL. ■ Simulated surgical planning indicates that anterior catheter trajectories are feasible in patients with early manifest HD to infuse the caudate and putamen (Figure 3). Figure 3. Potential anterior catheter trajectories for the delivery of AMT-130 in adults with early manifest HD ■ To translate preclinical efficacy to a HED, a bio- analytical data model using preclinical data from HD mouse and pig models was generated, based on the relationship between concentration of vector genome copies and lowering of human mutHTT protein. ■ The modeling predicted a linear relationship between lowering of brain mutHTT protein and the number of AMT-130 genome copies (Figure 4). Figure 4. Regression plot AMT-130 genome copies versus human mutHTT expression Human mutHTT (%) 125 100 75 50 25 0 10 4 AMT-130 vector genome copies 10 5 10 6 10 7 mutHTT, mutant huntingtin protein. ■ The regression plot showed that the correlation between the vector concentration and effect is irrespective of the animal species and brain size, as long as it contains human HTT gene sequence. ■ The calculated AMT-130 HED to achieve a 75% lowering of mutHTT in the striatum and 50% in the frontal cortex was 6 × 10 13 genome copies per brain. The estimated clinical doses for the phase I/IIa clinical study in patients with early manifest HD are based on the achieved NHP brain genome copies and scale-up factor (Table 2). Table 2. AMT-130 gene therapy HED calculation based on bioanalytical modeling Total genome copies per brain Total injection volume per hemisphere Anticipated mutHTT lowering Striatum Cortex Low dose 6 × 10 12 1.5 mL 50% 25% High dose 6 × 10 13 1.5 mL 75% 50% Concentrations for lower doses are based on the model, keeping the injection volume constant to ensure striatal fill of >50%. HED, human equivalent dose; mutHTT, mutant huntingtin protein CONCLUSION ■ The AMT-130 HED and injection volumes to lower mutHTT in the brains of adult patients with early manifest HD are based on bioanalytical modeling and ~50% filling of the striatum. ■ Preclinical data in HD mice shows that a 25% to 50% lowering of mutHTT ameliorates the molecular, neuropathological, metabolic, and clinical phenotype. ■ Bioanalytical modeling predicts that 6 × 10 12 genome copies per brain delivered by real-time MRI-guided CED will lower mutHTT in the striatum and cortex by 50% and 25%, respectively. A higher dose at 6 × 10 13 genome copies per brain is expected to lower mutHTT by 75% in the striatum and 50% in the cortex. ■ These doses will be tested in a dose-escalation, double-blind, imitation surgery-controlled phase I/IIa clinical study cleared by the FDA. REFERENCES 1. Miniarikova J, et al. (2018) Mol Ther. 26(4):947-962. 2. Miniarikova J, et al. (2016) Mol Ther Nucleic Acids. 22;5:e297. 3. Miniarikova J, et al. (2017) Gene Ther. 24(10):630-639. 4. Evers MM, et al. (2018) Mol Ther. 26(9):2163-2177. 5. Spronck EA, et al. (2019) Mol Ther Methods Clin Dev. 16(13):334-343. 6. Yin D, et al. (2009) J Neurosci Methods. 176(2):200-205. 7. Tabrizi SJ, et al. (2009) Lancet Neurol 8(9):791-801. DISCLOSURES M. Evers, M. de Haan, A. Valles. E. Sawyer, S. v Deventer, J. Higgins, and P. Konstantinova are uniQure B.V. employees. S Gill is Medical Director of Renishaw PLC. RAC Roos’s institute has received a grant for a clinical trial (TEVA). Translating Preclinical Data to a Human Equivalent Dose for AMT-130 AAV Gene Therapy for Early Manifest Huntington’s Disease Patients Melvin M. Evers 1 , Martin de Haan 1 , Astrid Valles-Sanchez 1 , Eileen Sawyer 2 , Steven S. Gill 3 , Raymund Roos 4 , Sander van Deventer 1 , Joseph J. Higgins 5 , and Pavlina Konstantinova 1 1 Research and Development, uniQure B.V., Amsterdam, the Netherlands; 2 Medical Affairs, uniQure, Lexington, MA, USA; 3 North Bristol NHS Trust, Southmead Hospital, Bristol, UK; 4 Leiden University Medical Center, Leiden, the Netherlands; and 5 Clinical Development, uniQure, Lexington, MA, USA ABSTRACT NUMBER. 14
Transcript of Translating Preclinical Data to a Human Equivalent Dose ...
Presented at the International Congress of Parkinson’s Disease and Movement Disorders® Nice, France, September 22-26, 2019
BACKGROUNDHuntington’s disease (HD) is a fatal neurodegenerative disorder caused by a CAG trinucleotide repeat expansion in the huntingtin (HTT) gene. The results of proof-of-concept studies in HD rodent models have been difficult to translate to humans because of significant differences in neuroanatomy and brain size. This is particularly relevant for gene therapy approaches, where distribution achieved upon local administration into the parenchyma is dependent on brain size and structure.1 The gene-lowering therapy being developed by uniQure is based on the next-generation miQURE™ technology targeting huntingtin mRNA.2 The DNA expression cassette encoding the miHTT is delivered using recombinant adeno-associated viral vector serotype 5 (rAAV5-miHTT; AMT-130) (Figure 1).
Figure 1. Mechanism of action of AMT-130
1. Upon one-time intracranial parenchymal injection of AMT-130, rAAV5-miHTT binds to neuronal cell-surface receptors and is internalized.
2. Transport to the nucleus and uncoating of the miHTT transgene which remains mostly episomal.
3. Expression and processing of the miHTT transgene by the endogenous RNA interference machinery.
4. Hairpin structured precursor is transported to the cytoplasm and further processed to mature guide miHTT. No passenger strand is formed, strongly limiting the risk of off-target activity.
5. Mature miHTT is loaded in the RNA-induced silencing complex and binds to HTT mRNA.
6. HTT mRNA is cleaved and degraded, resulting in lowering of huntingtin protein translation.
HTT, huntingtin; miHTT, microRNA targeting human HTT.
Preclinical data in HD animal models shows that lowering aberrant HTT mRNA and mutant (mut) HTT protein species by AMT-130 ameliorates the molecular, neuropathological, metabolic, and clinical phenotype in HD.3-5 Good laboratory practice (GLP) toxicology and safety studies in non-human primates (NHPs) have shown excellent tolerability and safety after a single administration of AMT-130 by intraparenchymal convection-enhanced delivery to the striatum.
OBJECTIVE ■ To determine the human equivalent dose (HED) of
AMT-130 to lower HTT RNA and mutHTT protein in the brains of adults with early manifest HD.
METHODS ■ Volumetric magnetic resonance imaging (MRI)
was performed on 19 patients from the outpatient neurological clinic.
■ T1- and T2-weighted MRI images with contrast were reconstructed and processed using in-house software to determine putamen and caudate nucleus volumes.
■ T2 volumes were used to estimate the volume of perivascular spaces in each putamen.
■ AMT-130 was administered bilaterally to the caudate nucleus and putamen in NHPs using real-time, MRI-guided convection-enhanced delivery (CED).
■ Real-time volume of distribution (Vd) and volume of infusion (Vi) data from NHPs were used to estimate a scale-up factor for the AMT-130 HED.
■ The HED to lower mutHTT was extrapolated using a regression plot based on the brain biodistribution in small and large HD transgenic models.
RESULTSStriatal volume was analyzed in 19 MRI scans:
■ The mean putamen and caudate volumes in adult patients with early manifest HD were 3.11 cm3 and 2.24 cm3, respectively (Table 1).
Table 1. Striatal volumes in healthy adults, adults with early manifest HD, and NHPs
Brainstructure
Mean ± SD volume (cm3) per hemisphere
Healthyadults6
Early manifest HD
(n = 19)
Healthy NHPs
(n = 22)6
Putamen 3.57 ± 0.17 3.11 ± 0.54 0.55 ± 0.01Caudate 2.73 ± 0.06 2.24 ± 0.36 0.41 ± 0.02Striatum 6.33 ± 0.44 5.17 ± 0.88 0.97 ± 0.04
cm3, cubic centimeters; HD, Huntington’s disease; NHPs, non-human primates; SD, standard deviation.
■ Striatal volumes in HD were approximately 13% (putamen) and 18% (caudate) less than those typically observed in healthy adults6 (Figure 2).
Figure 2. Sagittal 3T volumetric MRI scans showing progressive brain atrophy in adults with early manifest HD
Control Pre-manifest HD Early manifest (Stage 1/2 HD)
~30% striatal atrophy;10% decrease in total brain volume
Modified from Tabrizi SJ, et al.7 Volumes are corrected for intracranial volume. HD, Huntington’s disease; MRI, magnetic resonance imaging.
The infusion parameters for MRI-guided CED of AMT-130 in humans per hemisphere was based on the following:
■ 200 μL filled ~50% of the NHP striatum6 with a Vd/Vi ratio of 2.0.
■ A conversion factor of 5.3 was calculated based on the striatal volumes in adult patients with early manifest HD to achieve the same degree of AMT-130 filling in humans.
■ A Vd/Vi ratio of 2.0 and an infusion volume of 1.50 mL per striatum is predicted to fill ~50% of the structure.
■ The putamen will be infused twice with 0.50 mL and the caudate once with 0.5 mL.
■ Simulated surgical planning indicates that anterior catheter trajectories are feasible in patients with early manifest HD to infuse the caudate and putamen (Figure 3).
Figure 3. Potential anterior catheter trajectories for the delivery of AMT-130 in adults with early manifest HD
■ To translate preclinical efficacy to a HED, a bio-analytical data model using preclinical data from HD mouse and pig models was generated, based on the relationship between concentration of vector genome copies and lowering of human mutHTT protein.
■ The modeling predicted a linear relationship between lowering of brain mutHTT protein and the number of AMT-130 genome copies (Figure 4).
Figure 4. Regression plot AMT-130 genome copies versus human mutHTT expression
Hum
an m
utH
TT (%
)
125
100
75
50
25
0104
AMT-130 vector genome copies105 106 107
mutHTT, mutant huntingtin protein.
■ The regression plot showed that the correlation between the vector concentration and effect is irrespective of the animal species and brain size, as long as it contains human HTT gene sequence.
■ The calculated AMT-130 HED to achieve a 75% lowering of mutHTT in the striatum and 50% in the frontal cortex was 6 × 1013 genome copies per brain.
The estimated clinical doses for the phase I/IIa clinical study in patients with early manifest HD are based on the achieved NHP brain genome copies and scale-up factor (Table 2).
Table 2. AMT-130 gene therapy HED calculation based on bioanalytical modeling
Total genome copies
per brain
Total injection
volume per hemisphere
Anticipated mutHTT lowering
Striatum CortexLow dose 6 × 1012 1.5 mL 50% 25%
High dose 6 × 1013 1.5 mL 75% 50%
Concentrations for lower doses are based on the model, keeping the injection volume constant to ensure striatal fill of >50%.
HED, human equivalent dose; mutHTT, mutant huntingtin protein
CONCLUSION ■ The AMT-130 HED and injection volumes to lower
mutHTT in the brains of adult patients with early manifest HD are based on bioanalytical modeling and ~50% filling of the striatum.
■ Preclinical data in HD mice shows that a 25% to 50% lowering of mutHTT ameliorates the molecular, neuropathological, metabolic, and clinical phenotype.
■ Bioanalytical modeling predicts that 6 × 1012 genome copies per brain delivered by real-time MRI-guided CED will lower mutHTT in the striatum and cortex by 50% and 25%, respectively. A higher dose at 6 × 1013 genome copies per brain is expected to lower mutHTT by 75% in the striatum and 50% in the cortex.
■ These doses will be tested in a dose-escalation, double-blind, imitation surgery-controlled phase I/IIa clinical study cleared by the FDA.
REFERENCES1. Miniarikova J, et al. (2018) Mol Ther. 26(4):947-962.2. Miniarikova J, et al. (2016) Mol Ther Nucleic Acids. 22;5:e297.3. Miniarikova J, et al. (2017) Gene Ther. 24(10):630-639.4. Evers MM, et al. (2018) Mol Ther. 26(9):2163-2177.5. Spronck EA, et al. (2019) Mol Ther Methods Clin Dev. 16(13):334-343. 6. Yin D, et al. (2009) J Neurosci Methods. 176(2):200-205.7. Tabrizi SJ, et al. (2009) Lancet Neurol 8(9):791-801.
DISCLOSURES M. Evers, M. de Haan, A. Valles. E. Sawyer, S. v Deventer, J. Higgins, and P. Konstantinova are uniQure B.V. employees. S Gill is Medical Director of Renishaw PLC. RAC Roos’s institute has received a grant for a clinical trial (TEVA).
Translating Preclinical Data to a Human Equivalent Dose for AMT-130 AAV Gene Therapy for Early Manifest Huntington’s Disease Patients
Melvin M. Evers1, Martin de Haan1, Astrid Valles-Sanchez1, Eileen Sawyer2, Steven S. Gill3, Raymund Roos4, Sander van Deventer1, Joseph J. Higgins5, and Pavlina Konstantinova1
1Research and Development, uniQure B.V., Amsterdam, the Netherlands; 2Medical Affairs, uniQure, Lexington, MA, USA; 3North Bristol NHS Trust, Southmead Hospital, Bristol, UK; 4Leiden University Medical Center, Leiden, the Netherlands; and 5Clinical Development, uniQure, Lexington, MA, USA
ABSTRACT NUMBER. 14
