HilleVax announced in July 2024 that topline data results from NEXT-IN1, a Phase IIb trial of HIL-214, reveal a failure to meet primary and secondary efficacy endpoints. This trial in infants around 5 months old at time of initial vaccination was conducted after a Phase IIb study in adults demonstrated “statistically significant efficacy” against moderate or severe acute gastroenteritis (AGE) caused by norovirus. The company plans to discontinue further development of HIL-214 in infants but will explore the potential for continued development of HIL-214 and HIL-216, a Phase I-ready candidate, in adults.
HIL-214 fails to meet endpoints
HIL-214 is a norovirus bivalent GI.1/GII.4 virus-like particle (VLP) vaccine intended for active immunisation to prevent AGE caused by norovirus. The latest trial was a Phase IIb, randomised, double-blind, placebo-controlled clinical trial to evaluate the efficacy, safety, and immunogenicity of HIL-214 in infants at sites in the US and Latin America. HilleVax states that in the study there were 51 primary endpoint events: 25 in the vaccine arm and 26 in the placebo arm. This resulted in vaccine efficacy of 5%.
“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 that was “consistent” with observations in the prespecified analysis of the first 200 subjects in this trial and in previously reported studies. Dr Rob Hershberg, Chair and Chief Executive Officer of HilleVax, is “disappointed” that the study did not meet its primary efficacy endpoint
“While HIL-214 previously showed clinical benefit in adults, NEST-IN1 was the first efficacy study conducted in infants for a norovirus vaccine candidate.”
Dr Hershberg suggested that 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.”
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