Norovirus Oral Tablet Vaccine Enters Phase 1b Trials

Vaxart enrolled its first participants for its dose-ranging and boosting regimen studies.

South San Francisco-based biotechnology company, Vaxart, announced it has enrolled its first patients in 2 phase 1b trials evaluating its oral norovirus pill vaccine candidate in a dose-ranging study in elderly subjects and a boosting regimen study, respectively.

In the dose-ranging, repeat dose trial, the investigational vaccine will be studied participants aged 55 to 80 years old, and it will evaluate the safety and immunogenicity of Vaxart’s VP1-based bivalent oral tablet vaccine. Study participants will be randomized into 2 cohorts stratified by age: cohort 1 will receive either a low dose vaccine candidate (1e10 I.U. n=16) or placebo (n=8). In cohort 2, participants will receive either a high dose vaccine candidate (1e11 I.U. n=16) or placebo (n=8). The study drug will be an oral tablet administered on days 1 and 29.

The tablet was developed to target the norovirus GI.1 Norwalk and GII.4 Sydney strains, which are the predominant strains affecting humans. Vaxart’s oral tablet vaccine candidate is designed to produce antibodies against norovirus locally in the intestine.

For the boosting regimen study, the company is planning to enroll 30 subjects aged 18 to 55 years old. The participants will be randomized into 3 cohorts: cohort 1 will receive the vaccine candidate on day 1 and week 4 of the study; cohort 2 will receive the vaccine candidate on day 1 and week 8 of the study; cohort 3 will receive the vaccine candidate on day 1 and week 12 of the study. The study is looking at safety and immunogenicity for its endpoints.

“Many think norovirus is just a virus that may infect those who go on cruises, when in fact it is a potentially fatal illness that affects around 20 million Americans every year, primarily young children or the elderly,” Vaxart CEO Andrei Floroiu, said. “Norovirus is the most common viral cause of epidemic gastroenteritis and is a major public health problem with no approved vaccine available.”

Vaxart has also developed an oral vaccine for COVID-19, which is also in clinical trials. Contagion spoke to Vaxart Chief Scientific Officer and Founder Sean Tucker, PhD, last year about the vaccine and the interview can be viewed here.

“The norovirus program is part of our broader strategy to develop prophylactic vaccines that target a range of pathogens,” Floroiu said. “We believe we have the capabilities to develop a new generation of orally administered vaccines, with the potential to benefit public health by protecting at-risk populations against infectious diseases.”

For those patients who might be hesitant about taking injections, an oral tablet vaccine could be an attractive alternative.