InThera, a Korean biotechnology company, announced Thursday that it has received clearance from the Ministry of Food and Drug Safety (MFDS) to initiate a phase 1 clinical trial of its norovirus vaccine candidate, INT101.

INT101 is a recombinant virus-like particle (VLP) vaccine designed to prevent foodborne illness caused by norovirus. The upcoming trial will evaluate the safety and immunogenicity of three intramuscular doses of INT101 in healthy adults.

InThera is developing a trivalent VLP-based norovirus vaccine with funding support from Korea’s Vaccine Commercialization Technology Development Project Group, part of the Ministry of Health and Welfare. The company says its candidate leverages a proprietary VLP platform that enables rapid and high-yield production using E. coli expression systems.

“Our VLP vaccine is based on proprietary core technology, allowing for high-purity, uniform particles through optimized in vitro self-assembly of antigen proteins, without cellular contaminants,” InThera CEO Choi Deog-young said.

Norovirus is a highly contagious virus that causes acute gastroenteritis, typically spread through contaminated food or water. According to the World Health Organization (WHO), the virus infects around 700 million people annually and results in approximately 200,000 deaths worldwide. Due to its ability to cause infection with only a small number of viral particles, norovirus has long been a challenge for public health systems across the globe.

Unlike other viruses, norovirus cannot be cultured in laboratory conditions, making it difficult to develop traditional, propagation-based vaccines. As a result, researchers have turned to alternative technologies such as VLPs, which mimic the structure of viruses without containing infectious material.

Despite the significant global burden of norovirus, no vaccine for the virus has been approved to date. International development efforts have also faced considerable setbacks.

U.S. biotech firm Moderna, which previously attempted to develop a norovirus vaccine using its mRNA platform, recently halted its clinical program. Similarly, HilleVax—a joint venture between Takeda and Frazier Healthcare Partners—discontinued a pediatric trial after it failed to demonstrate efficacy last July, although studies in adult populations are still ongoing.

One of the main challenges in norovirus vaccine development is the virus’s high genetic variability. To date, at least 48 genotypes have been identified, and new strains continue to emerge. Common variants include GII.4, GII.3, and GII.2, while newer strains like GII.17 have been detected in Europe, the U.S., and other regions.

Aside from InThera, CHA Vaccine Institute is also working on a universal norovirus vaccine using recombinant VLP technology in Korea. The company plans to develop a quadrivalent formulation incorporating four VLP antigens with an immune-enhancing adjuvant.