Parkin GT Executive Summary, Clinical Strategy, And GBA PET Rationale

Parkin GT Development Timeline And Preclinical Plan

Top planning notes:

(polyubiquitination ... 결과 없는데?) 여기서 VG, protein -> -> 3 (PGK1, CBh, and synapsin 1) were selected.
 
30 mice (male) + 30 mice (female) (Nov, 2020, planned)
50 mice (male) + 50 mice (female) (Feb, 2021, planned)
이 시험 완료되었음
 
202203:
Expression cassettes prioritized:
2 promoters (PGK and SynI) and 3 codon-optimized cDNAs
 
AAV9 vectors carrying 3 codon-optimized PRKN cDNA sequences (CpG5-2, 5-4, and 0-3) with PGK1 promoter are being evaluated in vitro and in vivo.

Table anchors:

Row / area	Content
NHP	[in vivo POC: Toxin mice] with 1-2 cassettes
MPTP + Parkin KO	HAMRI; pilot study from Jul2022 (HAMRI), -> main study from Oct2022 ->
ROA studies by ICM & Surgery	(1-2 rAAVs) (-> one capsid 결정하겠네); NSTM불필요일것
Neurosurgical/device development note	Fergus proposed an imaging step, a 7-days exploratory study and a 14-days pilot study before the main biodistribution study for device development for the neurosurgical approach.
CRO note	Takeda has worked with 3 CRO's with neurosurgery and ICM experience: CRL - Laval, CRL - Mattawan, NBR - Michigan. One of the 3 sites will be selected by end-Jul after on-site CRO visits.
DMPK / NHP	1M BD study 이슈; (i) triggered by mouse dosing study results, from 202312; (ii) 아니면 202303에 그냥 시작; 이슈: HA필요 (TO estimate HED How?); NSTM여기서 개입하면 될 것
Tox (DSRE) / NHP	3M non-GLP tox (triggered by CN): 2 candidates; 1M and 6M GLP tox (triggered by CS): 1 candidates
MC1	In vitro MC1 study complete: 2020/11~2021/03; 2022/02: MC1 PET clinical study start; 2023/02: MC1 PET clinical study compete; MC1 animal study; BCS

AAV9-Parkin Expression Comparisons

Vectors Carrying Codon-Optimized PRKN cDNA

Caption:

1 Vectors carrying codon optimized PRKN cDNA showed Parkin protein expression in the SN and striatum of PRKN KO mice (pk044 showed equivalent expression to PK012)

Plot anchors:

Plot element	Content
Y-axis	Parkin protein (% of PK012)
X-axis / bars	PK012, PK044, PK045, PK046
Dose annotation	3.2x; 1.6x 10^? VG/injection
Summary	N=4 (mouse); Mean±SEM

Human Parkin Protein In iPSC-DA

Title/caption:

AAV infection in PRKN KO hiPSC-DA neurons
3 Human Parkin protein in iPSC-DA - codon-optimized cDNAs

Plot anchors:

Plot element	Content
Y-axis	Parkin protein (pg/mg total protein)
X-axis	MOI; 10^3, 10^4, 10^5, 10^6
Legend	PK012 (WT), PK044 (CpG5-2), PK045 (CpG5-4), PK046 (CpG0-3)
Reference line	Parkin levels in control neurons
Summary	N=3; Mean±SEM

AQB1, Budget/FTE Artifact Links, And Clinical Strategy

Artifact/link text:

AQB1 (202111)
Parkin GT AQB1 for PRC PE 20211111.pptx
2021-11-10(11) AQB1 (Asset Quality Board)
 
Budget & FTE
Parkin GT PE to IND budget FTE template.xlsx

Row	Preclinical	Prodromal	Symptomatic
pathology	x	DA neuronal loss 0-50%	DA neuronal loss >50%
population	Family history, (sporadic 은 기대못할 것)	Family history + DATScan + (no RBD) + updrs 4 (?)점, kinetic tremor 제외?	blank
Preclinical support?	Yes	Yes	Sx reversal (Chung et al. 2020, PMID 32494688)
decision note	GT accepted? Onset variable. Accepted only to pathogenic variants	blank	blank
decision note	Large trial needed, hetero not plausible,	blank	blank

Rationale Of GBA PET

Rationale text:

Rationale of GBA PET
 
PK-PD-Efficacy relationship
- Protein is the main PK readout for PK-PD analysis
(CSF GBA protein's caveats)
- We need to see SN
 
• SN의 Signal change가 most clinically meaningful PD index일 것이다
• 비록, (Efficacy 없이) PK-PD relationship 관점만 보면 (가장 가능성 있는 PD index인) CSF GlcCer 와 가장 잘 맞을 것은 CSF (total) GBA protein 혹은 whole brain (total) GBA PET signal 이겠지만,
- 나중에 aSyn PET 과 regional pattern 맞춰봐야함),
 
[부가적 rationale:]
- CSF GBA protein
  • No healthy data (이건 향후 보유 예정)
  • No consensus on CSF GBA BL level in PD (only Mullin 2020 Ambroxol P2 data), that shows variability 150-310 pg/mol
- CSF GBA ACTIVITY
  • (CSF니까) Affected by lysosomal- & cellular- secretion
  • Variable: adult normal range: 1.1 - 8.1 μmol/L/d): prevail.
  • In some patients, undetectable (LLOQ: 0.56 μmol/L/d).

Imaging-schematic title and step anchors:

GBA expression evaluation by imaging
 
1) Dynamic range with the normal GBA1-specific probe
2) Dynamic range with the GBA1-nonselective probe
 
Step1: To test if the PET probe can capture GBA1 with enough S/N ratio in the control matrix
Step2: To confirm if the probe can capture GBA1 in GBA-PD matrix with reduced GBA1 protein expression

Schematic labels at the bottom/statusbar overlap:

Control
GBA-PD
GBA-PD
GBA protein

Uncertain Spans

• polyubiquitination ... 결과 없는데? top note is partially cut at the top of the body crop.
• 1.6x 10^? VG/injection is not safely readable.
• The bottom GBA PET schematic is truncated by the photo/statusbar area; use adjacent capture if available before extracting the full schematic.