LigoCyte Pharmaceuticals, Inc. announced that it has initiated its third human clinical trial of its norovirus vaccine. The phase I/II study will assess safety and immunogenicity associated with LigoCyte's investigational, nasally-delivered, dry powder vaccine in healthy adults. The study will also assess potential protection against clinical symptoms of norovirus infection by including a live virus challenge of subjects that have received either the vaccine or placebo. Clinical studies to date have shown the vaccine to be immunogenic and generally well tolerated in human subjects.

"Norovirus infections are now being recognized as a widespread problem that can have very serious consequences," said Donald P. Beeman, CEO of LigoCyte. "The worldwide impact of this highly contagious virus has been increasingly appreciated with the continued closures of hospital wards, long-term care facilities, and schools."

Norovirus infection, well known as the "stomach flu," is the most common cause of acute gastroenteritis, afflicting nearly 23 million Americans annually. Norovirus infection is characterized by the acute onset of nausea, vomiting, abdominal cramps, diarrhoea, and occasionally fever. Severe clinical outcomes are associated with at-risk populations, where complications caused by infection can disrupt primary treatment regimens and even lead to death.

Noroviruses are highly infective and easily transmitted. Epidemic outbreaks occur in community environments, particularly hospitals, hotels, schools, and nursing homes, resulting in significant risk to immunocompromised individuals and mounting socioeconomic cost to families, the health care system and businesses. Military units are also affected, as outbreaks represent a significant readiness issue for naval vessels and land-based installations.

LigoCyte's norovirus vaccine is a needle-free, dry powder formulation based on virus like particle (VLP) antigens, which are highly purified protein products. By preserving the authentic conformation of the viral capsid, VLPs mimic the antigen presentation of the live virus while lacking the ability to reproduce or cause illness. LigoCyte's vaccine formulation also includes the adjuvant Monophosphoryl Lipid A, provided under license from GlaxoSmithKline, and chitosan (ChiSys) to enhance nasal delivery, under license from Archimedes Development Ltd. LigoCyte's challenge study will utilize a live Norwalk virus inoculum developed at Baylor College of Medicine with funding from the National Institutes of Health.

LigoCyte is an immunology company developing a new generation of vaccines for the prevention of infectious diseases. LigoCyte's expertise in virus-like particle vaccines supports a pipeline of enhanced products, including vaccines against norovirus, influenza and respiratory syncytial virus.