HilleVax Reports Topline Data From NEST-IN1 Phase 2b Clinical Study of HIL-214 in Infants

HilleVax, Inc. recently announced topline data results from NEST-IN1. NEST-IN1 is a Phase 2b, randomized, double-blind, placebo-controlled clinical trial to evaluate the efficacy, safety, and immunogenicity of HIL-214 in infants of approximately 5 months of age at the time of initial vaccination at sites in the US and Latin America.

In the NEST-IN1 study, there were 51 primary endpoint events with 25 in the vaccine arm (n=1,425) and 26 in the placebo arm (n=1,399) resulting in vaccine efficacy of 5% (95% confidence interval; -64%, 45%). The study did not meet its primary endpoint of efficacy against moderate or severe acute gastroenteritis (AGE) events due to GI.1 or GII.4 norovirus genotypes. No clinical benefit was observed across secondary endpoints. HIL-214 exhibited a safety and immunogenicity profile consistent with what was observed in the prespecified analysis of the first 200 subjects in NEST-IN1 and in previously reported studies.

“We are disappointed that the NEST-IN1 study did not meet its primary efficacy endpoint,” said Rob Hershberg, MD, PhD, Chairman and Chief Executive Officer of HilleVax. “While HIL-214 previously showed clinical benefit in adults, NEST-IN1 was the first efficacy study conducted in infants for a norovirus vaccine candidate. We believe the efficacy in the infant setting may have been impacted by the appearance of multiple emerging GII.4 strains in this trial. We sincerely thank the trial investigators, clinical sites and the HilleVax team for conducting a highly rigorous study, and we are deeply appreciative to the infants and families that participated in this trial.”

The NEST-IN1 study was conducted after a Phase 2b study in adults, NOR-211, demonstrated statistically significant efficacy against moderate or severe AGE due to norovirus. The company plans to discontinue further development of HIL-214 in infants and is exploring the potential for continued development of HIL-214 and HIL-216, HilleVax’s Phase 1 ready vaccine candidate, in adults.

HilleVax is a clinical-stage biopharmaceutical company focused on developing and commercializing novel vaccines. Its initial program, HIL-214, is a virus-like particle (VLP) based vaccine candidate in development for the prevention of moderate-to-severe acute gastroenteritis (AGE) caused by norovirus infection. Globally, norovirus is estimated to result in over approximately 700 million cases of AGE and 200,000 deaths per year, resulting in over $4 billion in direct health system costs and $60 billion in societal costs per year. The burden of norovirus falls disproportionately on young children and older adults. For more information, visit http://www.HilleVax.com.