HilleVax, Inc. announced results from NOR-213, a Phase 2 long-term immunogenicity follow-up clinical trial of adults and older adults who previously received HIL-214, the company's investigational virus-like particle (VLP) based vaccine for the prevention of moderate-to-severe acute gastroenteritis (AGE) caused by norovirus infection. NOR-213 included 528 adult and older adult subjects that were enrolled following participation in prior clinical studies of HIL-214, including NOR-107, NOR-204, and NOR-210. The subjects received either one or two doses of HIL-214 (GI.1/GII.4 VLP combination with 500 µg alum) with or without the adjuvant monophosphoryl lipid A. Among all dose regimens of HIL-214, GI.1-specific and GII.4-specific HBGA-blocking and pan-Ig responses to vaccination persisted to year 5 of the study and, at year 5, results were similar to those previously reported at year 3. These results further support a single dose of HIL-214 (15/50 µg GI.1/GII.4 VLP combination with 500 µg alum) without MPL as the intended regimen for future development in adults and older adults.

No adverse events were deemed related to HIL-214, and no new safety risks were identified during the study. The company anticipates presenting detailed data from the NOR-213 clinical trial at a future medical meeting.