Six presentations highlight significant
advancements across the Company's Gene Therapy platform
Preclinical data supports potential of
P-OTC-101 to correct severe Ornithine Transcarbamylase Deficiency
(OTCD) following a single dose
Data presented establishes proof-of-concept
for site-specific knock-in of a transgene using Cas-CLOVER™,
Poseida's high-precision gene editing technology
SAN
DIEGO, May 18, 2023 /PRNewswire/ -- Poseida
Therapeutics, Inc. (Nasdaq: PSTX), a clinical-stage cell and gene
therapy company advancing a new class of treatments for patients
with cancer and rare diseases, today highlights its two oral and
four poster presentations on the Company's preclinical gene therapy
programs and platforms at the American Society of Gene and Cell
Therapy (ASGCT) 2023 Annual Meeting, being held at the Los Angeles Convention Center in Los Angeles and virtually May 16 – 20, 2023.
"We are excited to highlight multiple advancements across our
gene therapy programs and platform technologies at ASGCT, which
underscore the significant progress our company has made in the
past year," said Brent Warner,
President, Gene Therapy at Poseida
Therapeutics. "We are making encouraging progress with our
P-OTC-101 program, where our hybrid LNP+AAV approach has shown its
potential to deliver a functional cure for severe, pediatric-onset
OTCD with a single dose. In addition, early preclinical data
utilizing our Cas-CLOVER and non-viral piggyBac®
technologies continue to show great promise as we seek to unlock
the potential of non-viral gene therapies for patients."
Oral Presentations
Title: Preclinical Proof-of-Concept: A Novel
Hybrid Gene Therapy Approach to Treat Severe Early-Onset Ornithine
Transcarbamylase Deficiency
Session Title: Metabolic, Storage, Endocrine, Liver and
Gastrointestinal Diseases I
Presentation Time: Thursday, May 18, 2023, 2:30 –
2:45 PM PST
Location: Room 403 AB
Abstract Number: 127
Ornithine Transcarbamylase Deficiency (OTCD) is an X-linked urea
cycle disorder that prevents the breakdown and excretion of
ammonia, allowing it to rise to toxic levels and affect the central
nervous system, leading to coma, seizures, brain damage, and death.
Poseida has developed P-OTC-101, a liver directed gene therapy
utilizing a hybrid lipid-nanoparticle (LNP) and adeno-associated
virus (AAV) delivery system based on its piggyBac® DNA
insertion system to enable integration of the therapeutic human OTC
gene into the genome. In this study, researchers demonstrated
correction of severe OTCD following a single dose in a stringent
mouse model of the disease. Researchers also reported preclinical
pharmacology showing dose-response behavior as well as favorable
translational safety and pharmacology in mice and non-human
primates using this hybrid platform approach, which supports
further development of P-OTC-101 towards evaluation in humans.
Title: Cas-CLOVER Technology Enables Precise Gene
Editing and Site-Specific Transgene Insertion in Mouse Liver
Session Title: Gene Targeting and Gene Correction:
Liver
Presentation Time: Thursday, May
18, 2023, 3:00 – 3:15 PM PST
Location: Room 515 AB
Abstract Number: 157
This presentation highlights the potential of Cas-CLOVER,
Poseida's high-fidelity, proprietary gene editing technology
co-formulated with guide RNAs as a single LNP. Data demonstrated
highly efficient editing and favorable tolerability in mice
following a single dose of Cas-CLOVER with extremely low off-target
editing in the liver. The study establishes proof-of-concept for
knock-in of a transgene using Cas-CLOVER and a fully non-viral
delivery system in mice and further supports the potential of this
technology to develop effective therapies for rare diseases.
Poster Presentations
Title: Demonstration of Human Factor VIII
Expression and Activity Following Single and Repeat Dosing of a
Non-Viral Integrating Gene Therapy
Session Title: Wednesday Poster Session
Session Date/Time: Wednesday, May 17,
2023, 12:00 PM PST
Location: West Hall A
Abstract & Poster Board Number: 638
P-FVIII-101 is a fully non-viral liver-directed gene therapy
combining Poseida's proprietary piggyBac® technology
with nanoparticle delivery for the treatment of Hemophilia A. This
study demonstrated the potential of P-FVIII-101 to produce durable
human FVIII expression over six months in an adult mouse model of
severe Hemophilia A following a single dose. The study also
highlighted the potential of repeat dosing to achieve therapeutic
levels of human FVIII activity. An integration site analysis
revealed a favorable insertion profile and well-controlled
integrated vector copy number. These data provide
proof-of-principle evidence toward a potential functional cure for
Hemophilia A.
Title: Development of a Novel Non-Viral Gene
Therapy Platform
Session Title: Thursday Poster Session
Session Date/Time: Thursday, May 18,
2023, 12:00 PM PST
Location: West Hall A
Abstract & Poster Board Number: 945
The piggyBac® DNA insertion system is a
transposon-based gene therapy platform that enables stable
integration of the therapeutic transgene into the genome, thereby
offering the potential for durable and lifelong activity. This
poster details formulation discovery work on an LNP comprising a
novel degradable ionizable lipid with unique capabilities for
efficient DNA delivery to the liver, as well as discovery and
optimization of an LNP-based delivery system capable of
co-encapsulating mRNA and DNA for delivery of piggyBac®
transposon system components.
Title: Editing of a γ-Globin (HBG1/HBG2)
cis-Regulatory Element in Human Hematopoietic Stem and Progenitor
Cells Using Cas-CLOVER™ Technology Reactivates Fetal
Hemoglobin
Session Title: Thursday Poster Session
Session Date/Time: Thursday, May 18,
2023, 12:00 PM PST
Location: West Hall A
Abstract & Poster Board Number: 1212
This study demonstrates that high-fidelity Cas-CLOVER nuclease
targeting of gamma globin genes provides efficient editing and
reactivation of fetal hemoglobin expression. Cas-CLOVER-mediated
gene editing of gamma globin genes was also shown to produce up to
70% positivity for fetal hemoglobin among differentiated red blood
cells. Further, Cas-CLOVER-mediated gene editing did not adversely
affect stem cell capabilities, including potential to produce the
red blood cell lineage. These data support Cas-CLOVER editing of
gamma globin genes as a potential therapeutic strategy for genetic
diseases such as β-thalassemia and sickle cell disease.
Title: Development and Optimization of Novel Super
piggyBac®-Based Hybrid Gene Therapy
Approach
Session Title: Friday Poster Session
Session Date/Time: Friday, May 19,
2023, 12:00 PM PST
Location: West Hall A
Abstract & Poster Board Number: 1318
This presentation describes the discovery and optimization of a
novel LNP formulation suitable for delivery of Poseida's super
piggyBac® transposase to the liver. In addition, these
studies highlighted in vivo safety and pharmacology of Poseida's
lead LNP formulation in mice and non-human primates for use in
liver-directed hybrid gene therapy applications. The presentation
further characterizes the use of Poseida's hybrid gene therapy
platform in a mouse model of OTCD to achieve disease resolution at
significantly lower doses of AAV. These data demonstrate the
versatility of the piggyBac® hybrid platform and its
potential to achieve durable transgene expression when administered
early in life.
About Poseida Therapeutics, Inc.
Poseida Therapeutics is a clinical-stage biopharmaceutical
company advancing differentiated cell and gene therapies with the
capacity to cure certain cancers and rare diseases. The Company's
pipeline includes allogeneic CAR-T cell therapy product candidates
for both solid and liquid tumors as well as in vivo gene therapy
product candidates that address patient populations with high unmet
medical need. The Company's approach to cell and gene therapies is
based on its proprietary genetic editing platforms, including its
non-viral piggyBac® DNA Delivery System, Cas-CLOVER™
Site-Specific Gene Editing System and nanoparticle and hybrid gene
delivery technologies. The Company has formed global strategic
collaborations with Roche and Takeda to unlock the promise of cell
and gene therapies for patients. Learn more at
www.poseida.com and connect with Poseida on Twitter and
LinkedIn.
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SOURCE Poseida Therapeutics, Inc.