HilleVax is a clinical-stage biopharmaceutical company focused on developing vaccines to prevent norovirus, the most common cause of viral acute gastroenteritis globally. HilleVax's lead asset is HIL-214, a bivalent virus-like particle (VLP)-based vaccine candidate targeting the two main norovirus genogroups responsible for most human infections. HIL-214 was originally developed by Takeda and licensed to HilleVax in 2021. While a Phase 2b trial in adults demonstrated 62% efficacy against norovirus, HilleVax's pivotal infant trial completed in July 2024 failed to meet its primary efficacy endpoint with no benefit observed across secondary endpoints. Following this failure, HilleVax is exploring strategic alternatives, including partnering, out-licensing, or a sale of the company or its assets. HilleVax also holds a second candidate, HIL-216, a hexavalent VLP vaccine targeting six norovirus genotypes, in-licensed from Chengdu Kanghua Biological Products in January 2024, with HilleVax holding worldwide rights outside China. HilleVax has no approved products and no product revenue, funding operations through capital raises. The company does not manufacture its own products, relying on third-party contract manufacturers. With only 14 full-time employees and its primary commercial path disrupted by the infant trial failure, HilleVax's future is highly uncertain.