LogicBio Therapeutics : ESGCT 2021 – Tyrosinemia

Delivering the hope of genetic medicine to people impacted by devastating diseases

1. novel endonuclease-free genome editing technology to edit hepatocytes in vivo led
   to a full molecular liver transplant and cured mice in preclinical models of Tyrosinemia Type 1

CW Ko, S Amarwani, J Vora, L Freland, N Ramesh, G Preston, Y Chen, J Liao, N Walsh, L Drouin, M Hebben, J Xiong, and M Nacht

P253, ESGCT 2021

2 HT1 indication overview

Tyrosinemia Type I and GeneRide™

• Hereditary Tyrosinemia Type 1 (HT1) is monogenetic disease caused by loss-of-function mutations in fumarylacetoacetate hydrolase (FAH), leading to accumulation of toxic metabolites causing multiple organ failure.
• Nitisinone (NTBC) plus diet restriction is an effective treatment and standard of care for HT1. However, significant unmet medical need remains due to requirement for lifelong strict adherence to medication and medical diet, impaired neurocognition and elevated risk of hepatocellular carcinoma (HCC) due to noncompliance.1
• GeneRide™ is a novel AAV-basedendonuclease-free genome editing technology showing superior durability compared to canonical AAV gene transfer.2 In addition, leveraging the regenerative nature of liver, we have observed selective expansion of GeneRide-edited hepatocytes in disease animal models that cause liver stress, such as Methylmalonic Acidemia.3
• 1. Van Ginkel, WG., et al. "Long-Term Outcomes and Practical Considerations in the Pharmacological Management of Tyrosinemia Type 1". Pediatric Drugs (2019) 21:413-426
  2. Ko, CW., et al. "Durable and Efficacious Transgene Expression Driven by GeneRide™ in Liver Injury Models". ASGCT (2020)

Confidential

NTBC

3. Chandler, RJ., et al. "Promoterless, Nuclease-Free Genome Editing Confers a Growth Advantage for Corrected Hepatocytes in Mice with Methylmalonic

Acidemia". Hepatology 73 (2021): 2223-2237

3	GeneRideTM Overview

Confidential

GeneRideTM: designed to enable therapeutic levels of protein expression through non-disruptive integration

1

2 3

4

5

GeneRide construct delivered to nucleus with synthetic virus Homologous recombination driven integration

Transcription of fused mRNA via endogenous albumin promoter Protein expression: one read, two proteins (1:1 ratio)

ALB-2A (Albumin produced from edited hepatocytes modified with a 2A peptide):

• Functions as circulating biomarker for the platform
• Measurable in blood
• Preclinical studies showed that detection in blood indicated site-specific,non-disruptive integration
• ALB-2Alevels correlate to the number of hepatocytes edited

Note: Albumin locus is the site of integration for our liver-directed programs, including LB-001 and LB-301. For non-liver indications, alternative genes will be utilized

4 Initial PoC in FRG mice

Confidential

GeneRide cured the Tyrosinemia phenotypes in FRG mice

WK pd 0 1	5	9	16
GeneRide		Sac	Sac
Vehicle	NTBC as
NTBC ON
needed	NTBC OFF

• FRG mice (Yecuris, OR) lack murine FAH gene and quickly perish due to liver failure if not treated with NTBC. In this study, FRG mice were maintained on NTBC drinking water (8 mg/L) since birth and treated with GeneRide encoding human FAH (GR-hFAH) or vehicle.
• GeneRide treatment completely rescued the lethality phenotype observed in vehicle group, restored normal body growth, and normalized liver function despite NTBC discontinuation and normal diet.

% BW of WK1

	Body Weight Growth					ALT
NTBC	NTBC	NTBC			NTBC	NTBC NTBC
200 ON	as needed	OFF		150	ON	as needed	OFF
							perish
		WT mice		125			perish
150		(JAX4)	(U/L)	100
		GR-hFAH (n=8)	75			perish
		ALT
		All animals survived
100				50
		Vehicle(n=6)					perish
		All animals perished		25			Normal
							range

50					0
0	4	8	12	16	0	4	8	12	16

Weeks post dose

Weeks post dosing

Bilirubin (mg/dL)

			Bilirubin
		(terminal)
12
			13 (WK6)
9	10 (WK6)	12 (WK4)
6
11 (WK9)
			9 (WK9)
3			14 (WK4)
0.3						LLoQ
0.0
	Vehicle GR-hFAH

4. https://www.jax.org/jax-mice-and-services/strain-data-sheet-pages/body-weight-chart-000664

5 Initial PoC in FRG mice

Confidential

GeneRide-edited hepatocytes showed full liver replacement in FRG mice

WK pd 0 1	5	9	16
GeneRide		Sac	Sac
Vehicle	NTBC as
NTBC ON
needed	NTBC OFF

• Rapid selective expansion of GeneRide-edited hepatocytes was observed in FRG mice, as evidenced by >100-fold increase in the circulating GeneRide biomarker (ALB-2A) within 4 weeks post dose
• As GeneRide is hypothesized to edit only one albumin allele per cell, the observed 50% genomic editing frequency suggested that essentially all of the hepatocytes were replaced. Using immunohistochemistry to detect the FAH protein, we further confirmed absence of FAH-negative regions in liver sections from GeneRide-treated FRG mice

GeneRide circulating biomarker

Genomic editing frequency

NTBC

60

2A (ug/mL)

1000

100

ON

as Needed				OFF

hepatocytes	theoretical limit	*
50
40
30
% in
20

ALB-

10

1

0

2

4

6

8

10

weeks post dose

Int	10
gDNA
0.0
	Vehicle	GeneRide

*: data showing the genomic editing frequency in hepatocytes isolated from the GeneRide-treated liver.