Longhorn Vaccines and Diagnostics Presents New Data on its Best-In-Class Infectious Disease Vaccine and Antibody Portfolio at ECCMID 2024

Longhorn Vaccines and Diagnostics, a One Health company developing vaccines and diagnostic tools for global public health and zoonosis concerns, presented positive data from three key studies of its infectious disease franchise at the European Congress of Clinical Microbiology and Infectious Diseases (ECCMID) 2024. ECCMID is taking place online and in-person in Barcelona, Spain from April 27-30, 2024.

Longhorn's vaccine and antibody product candidates focus on rapidly mutating viruses that include influenza, coronavirus, and antimicrobial resistant pathogens. The candidates presented include LHNVD-105, an adjuvanted composite peptide vaccine that targets multiple stages of the viral replication process, and a monoclonal antibody cocktail that targets a protein that may play a significant role in allowing tuberculosis to remain in a latent stage.

Influenza is a prevalent zoonotic respiratory virus, with pigs acting as a middleman for generating new virus strains transferrable to humans, birds, and other swine with pandemic potential. This poses a major public health issue and challenges to the swine industry. The first of two studies on LHNVD-105, Longhorn's universal influenza vaccine, showcased how unconjugated multi-epitope peptides, formulated with AddaVax^TM adjuvant, generated antibodies that were broadly reactive across multiple influenza virus strains when administered to pigs at low doses. Results included:

• Pigs immunized with LHNVD-105 generated IgG antibodies that bound to multiple strains of influenza virus 21 days post primary immunization after a single dose.
• Pigs receiving low vaccine doses (1 and 5?g) generated binding antibodies to influenza viruses equal to or higher than pigs in the high dose groups (50 and 100?g).
• No adverse reactions to the vaccine were observed.

"We are very excited to present the first data from our universal influenza vaccine in pigs," said Jeff Fischer, President Longhorn Vaccines and Diagnostics. "Pigs are an ideal model for influenza and the results mirrored the significant rodent data that has been previously published."

Seasonal circulation of rapidly evolving influenza strains are potential threats in human populations. For individuals with increased risk of exposure to influenza or immunocompromised, new strains resistant to antiviral therapies pose a life-threatening risk. The second study on LHNVD-105 evaluated the binding and functional capabilities of four different isotype-specific anti-influenza mAbs in mice to determine their candidacy for a cocktail therapy approach to influenza. Results demonstrated:

• Anti-influenza mAbs LD9 (IgG1, anti-HA), NB5 (IgG2a, anti-NA), GA4 (IgG1, anti-Matrix), and CG6, (IgG3, anti-Matrix) bound equally well to H3N2, but differentially to other contemporary and pandemic strains.
• Anti-HA mAb LD9 and anti-Matrix mAb GA4 (both IgG1) preferentially bound to pandemic H5N1 influenza strain, while anti-Matrix mAb CG6 was more reactive with influenza B.
• Anti-NA mAb NB5 and anti-Matrix mAb CG6 both had higher affinities to H3N2 and influenza B, but reacted less well to H1N1 and H5N1.
• Neutralizing activity of all four mAbs was demonstrated against H1N1 and H3N2.

"Tuberculosis is one of the most common and deadly diseases in the World. Up to one third of the World's population has been infected with the bacterium Mycobacterium tuberculosis but does not have active disease," said Gerald W. Fischer, MD, CEO of Longhorn Vaccines and Diagnostics. "The heat shock protein may play a significant role in shielding the bacterium from the immune system and allowing it to survive. The data being presented suggests that both our heat shock protein vaccine candidate and monoclonal antibody cocktail could play a significant role in preventing and treating multi-drug resistant tuberculosis infections."

Mycobacterium tuberculosis (MTB) is a virus that is becoming increasingly resistant to antibiotics and a key pathogen contributing to antimicrobial resistance worldwide. The third study, conducted by the University of Pretoria, explored Longhorn's monoclonal antibodies for the prevention and treatment of infections caused by MTB and gram-positive bacteria. The study analyzed the binding capabilities of IgG2a (anti- heat shock protein (HSP16.3)) and IgG2b (anti- Peptidoglycan (PGN)) mAbs to clinical MTB isolates. Results found:

• Both IgG2a and IgG2b mAbs demonstrated good binding activity to live and ethanol-killed MTB, and to mid-logarithmic and stationary phase MTB.
• The mAbs demonstrated good binding to live clinical MTB isolates at concentrations as low as 0.25 µg/mL.

For more information about Longhorn, visit www.LHNVD.com.

About Longhorn Vaccines and Diagnostics

Longhorn Vaccines and Diagnostics is a closely held One Health company based in Maryland that is developing broad coverage vaccines and diagnostic tools for worldwide public health concerns and to prevent future pandemics. Since its inception in 2006, Longhorn has focused on developing broad coverage vaccines and diagnostic tools that can impact a pandemic on a global scale and at all socio-economic levels. Since pandemics flow between humans and animals, Longhorn products play a significant role to surveil, diagnose, prevent and treat the next infectious disease.