Vaxart announces norovirus vaccine candidate trial data published

Vaxart (VXRT) announced that complete data from the Phase 1b trial of its first-generation oral pill norovirus vaccine candidate in elderly adults have been published in Science Translational Medicine. The data, which show strong and durable antibody responses and induction of norovirus-specific antibody and T cell responses, support immunogenicity of the vaccine candidate in a patient population that often has age-related reductions in immune responses to injected vaccines. The vaccine candidate generated durable serum antibody responses, with all three dose cohorts demonstrating statistically significant increases in serum anti-VP1 IgA compared to the placebo cohort on day 29 and day 57. No statistically significant differences were found between the two age groups within each dosing cohort. Dose-dependent increases in vaccine-induced responses were also observed for serum anti-VP1 IgG in all vaccinated cohorts on day 29 and day 57 compared to pre-vaccination levels. The vaccine induced VP1-specific IgA mucosal-homing antibody-secreting B cells and this response was independent of age. The high-dose vaccine induced mucosal-homing T cells, which may contribute to protection against persistent infections. Oral administration of the vaccine stimulated strong and durable IgA responses in saliva and the nasal cavity. Overall, the vaccine was safe and well tolerated in older adults. All solicited events were mild to moderate, with no grade 3 events related to the vaccine. Headache and malaise/fatigue were the most common solicited symptoms reported in the week following vaccine administration; headache and malaise/fatigue were reported at similar rates in the placebo group.