La Jolla Institute for Immunology Discovers First Measles-Neutralizing Antibody, Paving the Way for Therapeutic Development
Discovery of First Measles-Neutralizing Antibody
The research team led by Dr. Erica Ollmann Saphire at the La Jolla Institute for Immunology (LJI) has discovered the first human neutralizing antibodies that fundamentally block the entry of the measles virus into cells. Worldwide, over 10 million measles infections occur annually due to vaccine hesitancy and other factors, but there are currently no approved therapeutics, resulting in a significant unmet medical need. The research team extracted over 100 monoclonal antibodies from memory B cells in the blood of vaccinated individuals, providing a scientific breakthrough for therapeutic development.
Dual-Target Cell-Blocking Mechanism
Analysis using cryo-electron microscopy (Cryo-EM) revealed that the four key antibodies selected strongly bind to the hemagglutinin (H) and fusion (F) proteins on the surface of the measles virus. The H protein-targeting antibody blocks the virus from attaching to the host cell surface, and the F protein-targeting antibody prevents the virus from physically penetrating the cell membrane. By elucidating this dual-pathway cell-blocking mechanism, it is now possible to design highly effective cocktail therapeutics that are resistant to variant viruses.
Efficacy Verified Through Animal Models
In preclinical studies using immunocompromised cotton rats, administration of these antibodies resulted in inhibition of measles virus replication in vivo and a reduction in viral load by over 500-fold, demonstrating remarkable therapeutic efficacy. As a result, the research team has begun to seek bio companies for joint research and commercial partnerships to move beyond the preclinical stage and begin full-scale clinical trials. Meanwhile, in the private sector, Invivyd (ticker: IVVD) is developing a measles antibody candidate, 'VMS063,' targeting the F protein, and is accelerating its progress with the goal of submitting an Investigational New Drug (IND) application by the end of 2026, creating a competitive landscape.
Prospects for Treating Infants and High-Risk Groups
Currently, the global measles vaccine market is estimated at approximately $2.02 billion (about 2.7 trillion won) as of 2025 and is dominated by global big pharma companies such as Merck, GSK, and Sanofi. However, infants under 12 months of age and immunocompromised patients cannot receive the live MMR vaccine, leaving them vulnerable to measles infection and life-threatening complications. The development of this neutralizing antibody therapeutic not only provides a post-infection treatment but also presents a new approach for passive immunization in high-risk groups who cannot be vaccinated, and is expected to create a large therapeutic market.
The fact that there are no approved therapeutics for the measles virus, which causes over 10 million infections annually, provides new drug developers with an opportunity to gain a dominant market share. This preclinical-stage antibody discovery by LJI presents a direct challenge to the dominance of Merck (MRK) and GSK in the commercial vaccine market, and lays the groundwork for creating a new market for infants and immunocompromised individuals who cannot be vaccinated. In the short term, technology transfer and joint research agreements for clinical entry of the substance will be activated, and in the medium to long term, competition with Invivyd (IVVD), which is developing 'VMS063' with the goal of submitting an IND by the end of 2026, will accelerate. In particular, similar to the success of Sanofi's RSV prophylactic antibody 'Beyfortus,' the market for long-acting passive immunization antibodies for infants has the potential to generate billions of dollars in revenue annually, which will accelerate capital inflows.