Slide 1: Targeting Hepatitis B cccDNA with a Sequence-Specific ARCUS Nuclease to Eliminate HBV In Vivo
Targeting Hepatitis B cccDNA with a Sequence-Specific ARCUS Nuclease to Eliminate Hepatitis B Virus In Vivo April 26, 2023 Global Hepatitis Summit Cassie Gorsuch, PhD VP Gene Therapy Discovery
Slide 2: Forward-Looking Statements
Forward-Looking Statements This presentation contains forward-looking statements, as may any related presentations, within the meaning of the Private Securities Litigation Reform Act of 1995. The Company intends such forward-looking statements to be covered by the safe harbor provisions for forward-
Slide 3: Disclosures
Disclosures • I am an employee of Precision BioSciences, Inc. (Nasdaq: DTIL) 3
Slide 4: ARCUS: Engineering Nature's Genome Editing System
ARCUS: Engineering Nature’s Genome Editing System • ARCUS is derived from I-CreI, a naturally-occurring green algae homing endonuclease • Single protein of two linked monomers, which recognize a 22 bp DNA target site • Can be optimized for high specificity • Small size (364 amino acids) facilitates
Slide 5: ARCUS Gene Editing: Rationale for HBV Cure
ARCUS Gene Editing: Rationale for HBV Cure ARCUS-mediated inactivation of cccDNA and integrated HBV could result in a ARCUS functional cure HBV Infected Hepatocyte LNP inactivate Chronic HBV (cHBV) unmet need is massive cccDNA US >860,000 cHBV infections Globally >200 million cHBV infections • >90%
Slide 6: Dual Action Therapeutic Strategy for HBV-Targeting ARCUS Nucleases
Dual Action Therapeutic Strategy for HBV-Targeting ARCUS Nucleases Outcomes cccDNA Targeting is Unique to ARCUS Degradation by Loss of cccDNA exonuclease Loss of HBsAg 1 HBV cccDNA DNA break HBV cccDNA occurs “Indel” via DNA Mutated cccDNA repair Loss of HBsAg Mutated HBV DNA 2 Integrated DNA break
Slide 7: ARCUS Nuclease Activity in HBV-Infected Primary Human Hepatocytes
ARCUS Nuclease Activity in HBV-Infected Primary Human Hepatocytes • In HBV-infected primary human hepatocytes (PHH), ARCUS-POL showed an 85% reduction in cccDNA and 30% of the remaining cccDNA contained indels. cccDNA Degradation cccDNA Indels ARCUS LNP 30% 150 ARCUS 30 (cccDNA/non-targeting) % To C
Slide 8: ARCUS Nuclease Activity in HBV-Infected Primary Human Hepatocytes
ARCUS Nuclease Activity in HBV-Infected Primary Human Hepatocytes • ARCUS-POL treated cells demonstrated an 80% reduction in extracellular HBV DNA and a 77% reduction in secreted sAg, and no change in albumin. Extracellular HBV DNA Extracellular HBsAg Extracellular Albumin 150 150 250 Non-targeting
Slide 9: HBV Episomal In Vivo Model
HBV Episomal In Vivo Model AAV-HBsAg ARCUS-POL Liver Injection LNP Injection Necropsy • AAV HBsAg Dose: 5e11vg • ARCUS-POL LNP Dose: 2 mg/kg • Weekly blood draws for HBsAg 9
Slide 10: Episomal Mouse Model—Molecular Analyses
Episomal Mouse Model—Molecular Analyses • The ARCUS-POL nuclease significantly reduced AAV copies in the liver compared to the PBS control group. • The remaining AAV had an average of 86% indels in the ARCUS-POL treated group. • The AAV degradation and indel formation resulting from ARCUS-POL cuttin
Slide 11: Episomal Mouse Study—Liver HBsAg Immunohistochemistry
Episomal Mouse Study—Liver HBsAg Immunohistochemistry • Mice treated with ARCUS-POL showed a significant loss in HBsAg in the liver compared to non-nuclease treated mice. Group 1: No Nuclease Group 2: ARCUS-POL Blue = Nucleus Brown = HBsAg Gorsuch et al, 2022. Molecular Therapy 11
Slide 12: cccDNA Integration into the Genome of HBV Infected PHHs
cccDNA Integration into the Genome of HBV Infected PHHs isolate and sequence junctions HBV HBV integrates fragment DNA Chromosomes Chromosomes with Chromosome Fragments Integrated HBV 12
Slide 13: cccDNA Integration into the Genome of HBV Infected PHHs
cccDNA Integration into the Genome of HBV Infected PHHs Mock (HBV only) ARCUS Cut Site known off- target site? Early-Generation ARCUS Treated Gorsuch et al, 2022. Molecular Therapy 13 13
Slide 14: cccDNA Integration into the Genome of HBV Infected PHHs
cccDNA Integration into the Genome of HBV Infected PHHs Mock (HBV only) ARCUS Cut Site known off- target site? Optimized ARCUS Treated Gorsuch et al, 2022. Molecular Therapy 14
Slide 15: Conclusions
Conclusions • ARCUS demonstrates high levels of editing against cccDNA with subsequent reduction of HBsAg and HBV DNA in PHHs. • We have demonstrated durable HBsAg reductions after a single LNP administration in an AAV mouse model of HBV. • Our gene editing approach demonstrates high on-target activ
Slide 16: Acknowledgements
Acknowledgements Precision BioSciences, Inc. • Emily Harrison • Greg Falls • Amod Joshi • Paige Nemec • Jason Holt • Tyler Goodwin • Amy Rhoden Smith • Wendy Shoop • Rob Brown • Jeff Smith • Emma Sevigny • Neil Leatherbury • Janel Lape • Forrest Karriker • Derek Jantz Gilead Sciences • Mei Yu • Dong
Slide 17: Dedicated To Improving Life
Overcome cancer. Cure genetic disease. Dedicated To Improving Life