Excision BioTherapeutics unveiled promising new data from its hepatitis B virus (HBV) and herpes simplex virus (HSV-1) keratitis programs at the American Society of Gene & Cell Therapy (ASGCT) Annual Meeting in New Orleans on May 13, 2025. The presentations highlighted the company's progress in developing CRISPR-based therapies aimed at curing serious viral infectious diseases.
The San Francisco-based biotechnology company presented data on two key programs: EBT-107 for chronic hepatitis B and EBT-104 for HSV-1 keratitis, demonstrating advancements in their proprietary gene editing technology platform.
EBT-107: Targeting Chronic Hepatitis B
A poster presentation at ASGCT showcased EBT-107's potential to reduce clinically-relevant biomarkers and HBV DNA integration, suggesting progress toward functional remission of chronic hepatitis B. The therapy employs Excision's CRISPR-based approach to target the viral genome.
Chronic hepatitis B affects approximately 296 million people worldwide and contributes to over 820,000 deaths annually from complications such as cirrhosis and hepatocellular carcinoma. Current treatments typically require lifelong administration and rarely achieve functional cure, highlighting the significant unmet medical need that EBT-107 aims to address.
"Our preclinical data demonstrates EBT-107's ability to target integrated HBV DNA, which is a critical barrier to achieving functional cure with current therapies," said a representative from Excision BioTherapeutics. "The reduction in key viral biomarkers suggests potential for durable viral suppression."
EBT-104: Addressing HSV-1 Keratitis
The company also presented compelling data on EBT-104, its gene editing therapy for herpes simplex keratitis (HSK), the leading cause of corneal blindness in the United States. Previous studies with EBT-104 demonstrated complete elimination of viral shedding in 92% of eyes in treated rabbits, suggesting curative potential.
HSK affects approximately 500,000 people in the United States alone, with many patients experiencing recurrent infections that can lead to progressive corneal scarring and vision loss. Current antiviral treatments manage symptoms but do not eliminate the latent virus, leaving patients vulnerable to recurrences.
"EBT-104 represents a potentially transformative approach to HSK treatment," noted a company scientist during an oral presentation. "By targeting the viral genome directly, we aim to eliminate the source of recurrent infections rather than merely suppressing symptoms."
The presentation highlighted how EBT-104 successfully reduced Herpes Virus DNA, addressing the root cause of recurrent infections in HSK. This approach could significantly improve outcomes for patients who currently face limited treatment options.
Advancing CRISPR-Based Viral Cures
Excision BioTherapeutics has established a growing pipeline of potential curative therapies for viral infectious diseases. The company's proprietary CRISPR-associated gene editing technology is designed to inactivate viral genomes by making precise cuts at multiple locations, reducing the likelihood of viral escape mutations.
The company has already demonstrated clinical progress with EBT-101, which successfully met its primary endpoint of safety and secondary endpoints of biodistribution and immunogenicity in a Phase 1/2 study (EBT-101-001).
"Our platform approach allows us to apply our gene editing expertise across multiple viral targets," explained a company executive. "The data presented at ASGCT reinforces the potential of our technology to address serious viral diseases with high unmet need."
Clinical Development Pathway
Excision BioTherapeutics is advancing its pipeline through a strategic development approach. While specific timelines for EBT-107 and EBT-104 clinical trials were not disclosed at the meeting, the company indicated that the positive preclinical results support continued development toward IND-enabling studies.
The company's lead program, EBT-101, has already demonstrated safety in clinical trials, providing validation for the platform technology that underpins both EBT-107 and EBT-104.
Industry experts attending the presentations noted the potential significance of these therapies. "The ability to target integrated viral DNA represents a significant advancement in our approach to chronic viral infections," commented an independent virologist present at the session. "If these preclinical results translate to humans, it could fundamentally change how we treat these conditions."
As Excision continues to develop its pipeline of CRISPR-based therapies, the company is positioned at the forefront of efforts to develop curative approaches for viral infectious diseases that have long been considered manageable but not curable with conventional treatments.
