Recently, with a surge in cases of respiratory syncytial virus (RSV) infection, competition among big pharmaceutical companies in the preventive antibody and vaccine market has intensified.
The U.S. pharmaceutical company Merck (MSD) has joined the market for preventive antibody injections for infants, which is dominated by France's Sanofi and the United Kingdom's AstraZeneca. Meanwhile, U.S. Moderna has entered the adult vaccine market, where the United Kingdom's GlaxoSmithKline (GSK) and U.S. Pfizer have been competing.
On the 9th (local time), Merck announced that its RSV preventive antibody injection for infants, Enflonsia, received product approval from the U.S. Food and Drug Administration (FDA).
RSV is a class 4 legal infectious disease; in Korea, it typically spreads during the winter season between October and March, while in the U.S., it spreads from November to April. Major symptoms include fever, headache, runny nose, and sore throat, which are similar to a cold, but it can be dangerous for infants, the elderly, and those with weakened immune systems. According to the World Health Organization (WHO), around 3 million children under 5 are hospitalized each year due to RSV infection, and of those, 100,000 die.
Before Enflonsia, the market was monopolized by Beyfortus, jointly developed by Sanofi and AstraZeneca. Beyfortus was approved in Europe in 2022 and in the U.S. in 2023. Last year, it recorded sales of 1.7 billion euros (approximately 2 trillion won) worldwide. In Korea, SK bioscience launched it this year.
Both Beyfortus and Enflonsia are monoclonal antibodies that bind to a specific antigen protein of the virus. They have a short-term effect of preventing virus infection as long as the antibodies are maintained in the human body after injection.
The two antibody injections target different antigen proteins of the virus, making direct comparison difficult. However, while Beyfortus has two dosing options based on the infant's weight, the new product Enflonsia has a single dosage, which is considered more convenient.
On the other hand, the preventive effect against RSV is superior in the predecessor, Beyfortus. Enflonsia reduced the incidence of RSV lower respiratory infection in clinical trials for infants by 60% compared to a placebo. In the same trial, Beyfortus showed a 75% reduction effect.
Competition in the adult RSV vaccine market is also intensifying. GSK's Arexvy and Pfizer's Abrysvo have been leading the competition, and Moderna's mRESVIA is expected to join this line-up after receiving FDA approval in 2024.
Vaccines induce an immune response by administering a non-toxic virus or parts of it to the human body, prompting the production of corresponding antibodies. When vaccinated, the body continues to produce antibodies, meaning the preventive effect against the virus lasts longer than that of antibody injections.
GSK's Arexvy was approved by the FDA in 2023 for RSV vaccination in adults aged 60 and older. Based on the results of a phase 3 clinical trial evaluating the immune response and safety of the RSV vaccine in 570 adults aged 50 to 59, the minimum age was expanded to 50 last year.
Pfizer's Abrysvo received FDA approval in 2023 for adults aged 60 and older and for pregnant women between 32 and 36 weeks. Last year, it also received approval for chronic disease patients and immunocompromised individuals aged 18 to 59.
Moderna's mRESVIA is the world's first messenger ribonucleic acid (mRNA) vaccine, approved for individuals aged 60 and older. It is the first case in which an mRNA vaccine, previously limited to the COVID-19 vaccine, has been expanded to other infectious diseases. The mRNA enters the body, synthesizing viral proteins and inducing an immune response.
The global disease forecasting agency Airfinity has projected that the RSV vaccine market will reach $10.5 billion (approximately 14 trillion won) by 2030. Global pharmaceutical companies have been conducting research and development (R&D) on vaccines targeting the F protein of the RSV virus, as proposed by the U.S. National Institutes of Health (NIH) over a decade ago.