Press Release

Eureka Therapeutics Announces Successful Preclinical Results of InvisiMask™ Human Antibody Nasal Spray Against SARS-CoV-2 Infection

– Newly published study reports InvisiMask™, a self-administered nasal spray, protects against SARS-CoV-2 infection for up to 10 hours in mice

– InvisiMask human antibody nasal spray is designed to neutralize SARS-CoV-2 from airborne droplets and particles in the nasal cavity, the primary entry point of infection

– Company is preparing an Investigational New Drug application with the U.S. Food and Drug Administration for a clinical trial of the InvisiMask nasal spray

Emeryville, California, December 14, 2020 – Eureka Therapeutics, Inc. announced today successful preclinical results from its InvisiMask™ Human Antibody Nasal Spray in mice, which offers protection against SARS-CoV-2 S pseudotyped virus infection for up to 10 hours. InvisiMask is an intra-nasal application of a proprietary human monoclonal antibody that is intended to be used as a prophylactic against contracting SARS-CoV-2 infection. Results of the study, which has not been peer reviewed, are available on the preprint server bioRxiv.

Eureka’s InvisiMask human antibody nasal spray is designed to neutralize SARS-CoV-2 from airborne droplets and particles in the nasal cavity, the primary entry point of SARS-CoV-2 infection. The Eureka antibodies function by binding to the S1 spike protein of SARS-CoV-2, the virus that causes COVID-19, and prevent them from binding to the ACE2 receptor on cells in the upper respiratory system. This blocks SARS-CoV-2 from entering cells and triggering an infection.

Eureka’s monoclonal antibodies have been engineered with a proprietary adhesion technology that increases the retention of the antibody on respiratory mucosal surfaces, extending the duration of protection from infection. Furthermore, the InvisiMask nasal spray can be stored and used at room temperature which would simplify distribution and expand access.

Eureka used a human antibody as the spike protein binder to reduce the risk of adverse effects from immunogenicity which might occur if the binder was an antibody of animal origin or a foreign peptide. In addition, Eureka’s antibodies were developed with high binding affinity and specificity to the spike protein, and can bind and inhibit more than 20 SARS-CoV-2 variants, including the highly infectious D614G mutation. At the lowest dose of 25 μg, the antibodies provided at least 10 hours of protection against infection to mice exposed to the highest viral load tested (107 virus particles administered intra-nasally). No adverse effects were observed in the pre-clinical studies.

“We envision a daily nasal spray that functions like an invisible mask in slowing the spread of COVID-19,” said Cheng Liu, PhD, President and CEO and Eureka Therapeutics. “Anti-SARS-CoV-2 antibodies have demonstrated their effectiveness in treating patients with confirmed cases of COVID-19 and the FDA recently granted two companies emergency use authorization to use them intravenously as a therapeutic. Using antibodies in a preventive nasal spray adds to the arsenal of tools that we have to fight the spread of COVID-19, and the concept can be applied to other airborne diseases. We are excited about the results and are working to advance the product for human use.”

“We have found Eureka’s antibodies to be quite potent against the SARS-CoV-2 virus,” said collaborator Warner Greene, MD, PhD, Professor of Medicine, Microbiology and of Immunology at UCSF and the founding Director of the Gladstone Institute of Virology and Immunology. “Their nasal spray is an innovative approach to preventing the spread of COVID-19 particularly in high-risk individuals.”

“A preventive nasal spray is a complement to vaccines, therapeutics and other preventive measures,” said Jan Lin, MD, a frontline physician treating COVID-19 patients in San Jose, California. “Certain populations such as young children, seniors, frontline health workers, athletes, people with severe allergies, or immunocompromised patients could benefit immediately from a nasal spray.”

Eureka is preparing an Investigational New Drug application with the U.S. Food and Drug Administration for a clinical trial of the InvisiMask nasal spray.

To learn more about InvisiMask nasal spray, visit www.eurekatherapeutics.com/COVID19.

ABOUT EUREKA THERAPEUTICS, INC.

Eureka Therapeutics, Inc. is a clinical-stage biotechnology company focused on developing novel cancer T cell therapies to improve the lives of patients with cancer. The company is developing safer and more effective T cell therapies for the treatment of solid tumors and hematologic malignancies using its ARTEMIS® cell receptor platform and E-ALPHA® antibody discovery platform. Its lead compound ET140203 is in a US-based Phase I/II clinical trial in patients with advanced hepatocellular carcinoma (HCC). The company is headquartered in the San Francisco Bay Area. For more information, please visit: www.eurekatherapeutics.com. Follow us on Twitter at @EurekaThera.

Contacts:

Eureka Therapeutics, Inc.
Natalie Liu
Investor Relations
510-318-9215
IR@eurekainc.com

KKH Advisors
Kimberly Ha
917-291-5744
kimberly.ha@kkhadvisors.com