GCB-BTV Executive summary tempo code, Biodistribution Studies, Comp Bio E-selectin, Competitor (Roche / BIAL LTI-291 / NCT05819359 ACTIVATE)

GCB BTV Executive summary: tempo code 43/6-100

LGE	PE	CN	PDE	CS	IND
	202406 PQR on 24-Apr NSRB on 20240606 PE on 20-Jun	202505	202505	202512	202612

Biodistribution Studies

#1. NHP Biodistribution/imaging study’

objective	content
	NHP imaging study with fcfFR cross-react with radiolabeled protein
	to observe the brain biodistribution and CSF/Blood PK of GCB-BTV delivery (correct?) — Yes. And also to see peripheral of interest where tox is concerned
Animal	will be limited because NHP can’t have fTFR KI, so the study #2 will provide information that would translate better to humans
Where	What radioisotope will be used in the study #2? TBD by Paul
Lead?	Gabi is generating D409V-fTFR-KI mouse
what and how will we image?	TBD by Paul McQuade group DDU Gabi is planning
	TBD. Maybe general PK assay without imaging is preferred

#2. Imaging study with hTFR mouse with radiolabeled protein

Comp Bio

ISELE (=E-selectin)

• ↑ TNFα and IL-1β → e-selectin induced on endothelium → E-selectin interacts with two major glycoprotein ligands, E-selectin ligand-1 (ESL-1) and PSGL-1, →
• NLRP3 inflammasome activation → ↑ inflammation
• In cancer cells, CD44, death receptor-3 (DR3), LAMP1, and LAMP2 were identified as E-selectin ligands present on colon cancer cells, [17]

Assay:

• Olink® Target 96 Cardiovascular III (P16581), Uses only 1 μL of biological sample

Competitor

Roche — GCB BTV (Gehrlein, 2023 #2475)

Preclinical

• In vitro binding,
• In vitro GBA activity
• In vitro cellular uptake: fig 2a, b, (total) GBA activity (using substrate, β-glucopyranoside)
• In vitro: staining, colocalising with lysosome,
• In vitro: ↓ GlcSph
• In vitro: staining coloc with LAMP1
• IN VIVO: plasma and brain exposure, ↓ GlcSph, ↓ NfL

BIAL (AGN-242647) (Lysosomal Therapeutics → BIAL)

Our in-house preclinical study indicates that potency of LTI-291 is insufficient to provide efficacy in the brain at clinically relevant doses. To activate GBA, LTI-291 required about 5 μM in biochemical (cell-free) conditions, over 10 μM in cell cultures, and 300 mg/kg administration in the mouse brain.

Clinical trial table

Phase	Trial / Identifier	Target population	status	number	design	Tx	Primary outcome	Secondary
1 (LTI-291-001) FIH	(LTI-291-001)	healthy aged volunteers (middle and older) (LTI-291-002) NTR6705; LTI-291-002; NL62048.056.17; NTRCN27917; CHDR1709; NL62048-056-17	COMPLETED	40 (planned 237)	DB, Placebo, MAD, 14d 40명	SAD FIH (LTI-291) planned 237 in MAD	To characterize the plasma and CSF (PK) of LTI-291 NeuroCart assessments about 1 percent of plasma LTI-291 entered the brain, achieving a concentration of 1 μM or better, based on the amount of free drug in CSF. This would be sufficient to double GBA activity.	glycolipid biomarker assessments, plasma, PBMCs CSF not mentioned
P2a (LTI-291-003)	EudraCT2017-002233-37; NL62047-056-17CHDR1708; NTR6598 (자꾸 이걸 p1b 라고도 부르네)	GBA+PD H&Y 1-4, MMSE>18 (LTI-291-003)		40	RCT, PLACEBO, two doses (10 & 60 mg/d) (1:1:1)	10, 30, 60 mg/d, placebo n-10/group 위: 056-17 HV, 이게 FIH (LTI-291-001)	[primary] Time from baseline to clinically meaningful progression on motor aspects of experiences of daily living (as assessed by ≥2-point increase from baseline in MDS-UPDRS Part II score and no improvement in the Motor Examination, as assessed by ≥0-point increase from baseline in MDS-UPDRS Part III score. Time from baseline to clinically meaningful progression on motor signs of the disease (≥5-point increase from baseline in the MDS-UPDRS Part III score)	CGI-C, PGI-C, MDS-UPDRS Total (I-IV), H&Y, PDQ-39 Safety, biomarker (PBMCs) and plasma were analyzed for glycosphingolipid (GSL; 5 GluCer species, 7 LacCer species, and GluSph) changes at Days 6, 14 and 28. CSF was analyzed for GSL changes by comparing a Day 28 CSF sample to pre-dose CSF.
P2 (NCT05819359 "ACTIVATE")	BIA 28-6156-201, 2022-501783-18-00	GBA+PD PD dx between 1 to 7 y, H&Y ≤2.5, and a MOCA ≥22. Subjects on a stable dose of PD symptomatic medication will continue to receive it throughout the study.		(n=10 per group) 39 finished, Dose-ranging	placebo 10, 30 or 60 mg once daily for 28 day, fMRI AND FDG-PET		At all doses, in PBMC: GluCer and LacCer 오히려 temporality increase (day 7-14, and stabilized (see 202004xxxx alzform) at day 27. (Question: e. Do you want to keep it increased? Then at what level? 그들주장: (on the salvage(=recycling) pathway) ceramide의 downstream 인 GlcCer & LacCer 를 올리자. ie, Let's increase GSL flux! 환자에서 이것들이 준 증거가 있나?)	GSL changes in GBA-PD patients with 'severe' mutations were larger than in those with 'mild' mutations
P2 = NL7061 LTI-291-004; LSO882EC-178821; NTR7299	(LTI-291-004)	GBA+PD GBA-PD WT	15 stopped, follow up (?)	15	Inclusion 28d	10 or 60 mg once daily for 28 day, fMRI AND FDG-PET: enhanced brain blood flow by arterial spin labeling, increased brain glucose metabolism by FDG PET, and better functional connectivity in the default mode network on fMRI scans. The effects were similar in all treated patients, but not statistically significant in this small cohort. (Analysis, by David Eidelberg's group): (2 placebo and 9 treated) revealed that "anti-Parkinsonian" changes were clearly seen in 2 of patients in the high-dose group. Both of these patients also produced the characteristic peripheral intracellular (PBMC2겠군) GluCer increase at 7 and 14 days.	P2 ongoing 1y test

GSL changes — Sato sho note

Sato sho: We never see transient increase in both. We can clearly conclude GCS inhibitor never show transient increase since we tried to see GlcCer at earlier time points. We never see transient increase in GlcCer in mouse after treatment of LTI-291 (at 76h in brain, QDx3, T-729 below). But this is just a WT C57 mouse data but not in mouse model.

CSF sample to pre-dose CSF.

GBA activation table (cell-free / iPSC-DaNs / SNCA tripl)

	WT (N370S/4MUG, pH4.7) cell-free assay	L444P iPSC-DaNs (reduction by cerezyme is defined as 100%)	SNCA triplication iPSC NEURONS FROM PATIENTS
GBA activation	(MICE) 118% at 300 mg/kg Cf) iPS: LTI-177 0.1 μM: 127%, LTI-179: 140% (20150217 Slides, p14) Cf) iPS: LTI-177 0.1 μM: 113, 211, 382% @ 0.1/1/10 μM Cf) NIH-758: ~170% (20150217 Slides, p12) EC350: 5.2 μM 3% at 300 mg/kg	Cf) NIH-758: ~170%	↓ by ~70%
GlcCer		No effect up to 10 μM
GlcSph			50%
aSyn			↓ by ~70%

Questions to BIAL

• aSyn? no quantitative correlation between GBA activity & CSF aSyn level
• All gba mutation? effective in at least (L444P, N370S, E326K)
• CSF data, No positive outcome, should be only effective in confined system (intracellular, particularly membrane)
• GlcSph detectible?
• LYSOSOMAL function, proteolysis?
• Ceramide 도 봤나? 우리 inhouse: ↓ (GD), BUT Guede 2017: ↑ Cer, ↑ LacCer

Uncertain Spans

location	transcription	uncertainty
GBA activation table / 113, 211, 382%	reads as written	the comma-separated percentages match the OCR; preserved verbatim.