NeoVac has reported positive first-in-human Phase 1 and Phase 2 clinical results for NeomiVac, an investigational mRNA-LNP covid-19 vaccine, marking the first clinical evaluation of the company’s proprietary next-generation lipid nanoparticle delivery platform. The data suggest an improved safety and tolerability profile compared with currently authorised mRNA covid-19 vaccines, supporting broader use of the platform across vaccines and therapeutic indications.

The results, which have been made publicly available as a preprint on The Lancet platform, come from a dose-escalation study in healthy adult volunteers vaccinated against SARS-CoV-2. The trial evaluated safety, tolerability and immunogenicity across multiple dose levels to generate early human data for NeoVac’s mRNA-LNP technology.

According to the company, NeomiVac demonstrated biological activity alongside favourable tolerability. NeoVac said the safety profile compared positively with approved mRNA vaccines from Moderna and Pfizer BioNTech, addressing one of the key barriers that has limited wider clinical adoption of mRNA-based medicines at clinically meaningful dose levels.

mRNA technologies have been validated through their use in vaccines for infectious diseases, most notably during the covid-19 pandemic. However, their application beyond prophylactic vaccination has faced challenges related to safety, tolerability and delivery efficiency. These constraints have limited exploration of mRNA approaches in areas such as cancer immunotherapy, inflammatory and autoimmune diseases, protein replacement and gene-based therapies.

NeoVac’s delivery platform has been designed to overcome these limitations through rational design of lipid nanoparticles. The company said the technology allows tuning of immunogenicity, biodistribution and pharmacokinetic profiles, with the aim of improving both safety and biological activity. NeomiVac uses LNPs optimised specifically for vaccination against infectious diseases, while the underlying platform is intended for broader therapeutic use.

The Phase 1 and Phase 2 study represents the first clinical proof-of-concept for the LNP platform. Improved tolerability observed in the trial may support repeat dosing and chronic administration, which are considered critical for expanding mRNA-based medicines beyond vaccines into long-term therapeutic settings.

Jan Egberts, ceo of NeoVac, said: “Our data suggest that next-generation mRNA-LNP technologies can combine meaningful biological activity with improved tolerability, opening the door to entirely new therapeutic possibilities.”

NeoVac said the findings support continued development of the platform across infectious diseases, vaccines and additional indications. Ongoing programmes include product candidates in cancer immunotherapy and inflammatory and immune-mediated diseases, with several efforts being advanced in collaboration with development partners.

The study also highlights the role of delivery technology in determining the safety and effectiveness of mRNA medicines. Advances in lipid nanoparticle design are increasingly viewed as a key factor in enabling broader clinical use of mRNA across diverse disease areas.

Adrian Hill, co-founder of the AstraZeneca covid-19 vaccine, added: “This work highlights how advances in delivery platforms can materially change the risk–benefit profile of vaccines and other mRNA-based interventions. Improved safety is not only beneficial for patients, it is also essential for expanding the scope of diseases that can realistically be addressed using mRNA technologies.”

Dan Peer, co-founder of NeoVac, said the results validate long-term investment in delivery science. He said: “mRNA is a remarkably powerful therapeutic modality, but its success depends critically on how it is delivered.”

The full manuscript, titled Safety, tolerability, and immunogenicity of NeomiVac, a candidate next-generation lipid nanoparticle mRNA vaccine against SARS-CoV-2 in healthy volunteers, is available on The Lancet preprint server.