LB 01.2 - Engineering FVIII protein for enhancing expression and secretion profile to achieve normal level of FVIII in plasma utilizing noninvasive transcutaneous ultrasound mediated gene delivery.

Sunday, June 23, 2024

09:45 – 10:00 ICT

Room: Plenary Hall

Presenting Author(s)

Ivan Krivega, PhD

Senior Director Gene Therapy
SonoThera
SOUTH SAN FRANCISCO, California, United States

Co-Author(s)

IK

Ivan Krivega

Senior Scientist
SonoThera
SOUTH SAN FRANCISCO, California, United States
JP

Julia Poniatowski

Senior Research Associate
Sonothera
South San Francisco, California, United States
DK

David Kim

Scientist
SonoThera
South San Francisco, California, United States
ED

Elizabeth Del Greco

Associate Scientist
SonoThera
South San Francisco, California, United States
SR

Surabhi Rao

Scientist
SonoThera
South San Francisco, California, United States
VF

Victor Foster

Senior Research Associate
SonoThera
South San Francisco, California, United States
BF

Bert Frederich

Senior Scientist
SonoThera
South San Francisco, California, United States
BC

Barry Campbell

Former employee
SonoThera
South San Francisco, California, United States
AA

Adel Alonso

Research Associate
SonoThera
South San Francisco, California, United States
GA

Glenda Arauz

Research Associate
SonoThera
South San Francisco, California, United States
CO

Celia Ortiz

Research Associate
SonoThera
South San Francisco, California, United States
OC

Oliver Chen

Research Associate
SonoThera
South San Francisco, California, United States
DB

Dhruv Bole

Senior Research Associate
SonoThera
South San Francisco, California, United States
KB

Katie Benthal

Associate Director
SonoThera
South San Francisco, California, United States
AR

Anagha Rao

Former employee
SonoThera
South San Francisco, California, United States
DS

David Satyadi

Research Associate
SonoThera
South San Francisco, California, United States
ZG

Zoya Gluzman-Poltorak

Former employee
SonoThera
South San Francisco, California, United States
SF

Steve Feinstein

CSO
SonoThera
South San Francisco, California, United States
KG

Kenneth Greenberg

CEO
SonoThera
South San Francisco, California, United States

Background: The recent approval of viral vector-mediated gene therapy for HemA provides the potential for a once-a-lifetime treatment option. However, several limitations including high product cost, preexisting immunity to viral vectors, lack of durable FVIII expression, and lack of redosing capability suggest the need to develop alternative non-viral HemA gene therapy treatments to overcome these major limitations.

Aims: To develop an engineered FVIII protein with superior expression and secretion profile and optimize transcutaneous ultrasound-mediated gene delivery (UMGD) for efficient delivery of FVIII expression vector to the liver.

Methods: Using genetic engineering and screening of next-generation DNA payload formats, we developed an optimized episomal DNA payload expressing an oversized FVIII transgene (FVIII-ST). In vitro and in vivo testing was used to confirm FVIII-ST activity relative to the clinically validated FVIII-V3. To evaluate the potential of UMGD as a nonviral HemA treatment option, we delivered an optimized HemA payload using proprietary acoustic energy profiles and FDA-approved ultrasound components.

Results: The FVIII-ST outperformed FVIII-V3 yielding several fold higher human FVIII expression and secretion in vitro and in vivo. By optimizing the UMGD in vivo delivery acoustic profiles, we have been able to efficiently deliver the FVIII-ST payload to the liver of normal and HemA mice and reach durable therapeutic levels of FVIII in mouse plasma without triggering liver toxicity. Repeated UMGD treatments led to a significant increase in transgenic FVIII levels in plasma up to normal levels, suggesting a redosing treatment regimen is feasible for elevating or maintaining a normal physiological level of circulating exogenous FVIII.

Conclusion(s): Highly potent engineered FVIII protein was developed along with a non-viral ultrasound-mediated mode of delivery raising up to normal FVIII expression level in Hemophilia A mouse model.