SK bioscience will advance a novel respiratory syncytial virus (RSV) monoclonal antibody for global health under license from the Gates Medical Research Institute (Gates MRI).

SK bioscience announced today that it has entered into a license agreement with Gates MRI, a nonprofit medical research organization, an affiliate of the Gates Foundation, to develop and commercialize a clinical-stage monoclonal antibody (mAb) candidate prophylactic treatment for the prevention of RSV infection.

While RSV prevention options, including maternal immunization and preventive antibodies, are available, gaps in protection remain. Maternal immunization requires vaccination during a specific window of pregnancy, which may limit coverage for some infants, and currently available preventive antibodies are high-cost interventions with access largely concentrated in high-income countries. As a result, some newborns and young infants are not adequately protected against RSV in certain settings.

The RSV preventive mAb candidate, engineered by Adimab in collaboration with Gates MRI is designed to be administered to newborns and infants born during or entering their first RSV season, with a single dose intended to provide rapid and durable protection through an RSV season. If the mAb candidate is proven safe and effective in clinical trials, this approach could support broader supply and expand access to RSV prevention, enabling more infants to benefit and helping to address current gaps where protection remains limited for a variety of reasons.

In preclinical studies, the antibody (known as RSM01) demonstrated strong inhibition of viral infection and replication in both in vitro and in vivo models, including activity against certain RSV strains reported to show reduced susceptibility to currently available licensed products. In a Phase 1a first-in-human study conducted in healthy adults in the United States, the candidate was shown to be generally safe and well-tolerated in healthy adults, and the data suggested the potential for sustained protection throughout the RSV season following a single administration. Based on these findings, SK bioscience plans to move swiftly into a Phase 1b clinical trial in infants to accelerate this mAb’s development.

Under the license agreement, SK bioscience has secured exclusive worldwide rights to commercialize the candidate mAb if proven safe and effective, including in high-income countries, with non-exclusive supply in India and Gavi-eligible countries. In addition, the agreement includes Global Access commitments by SK bioscience that are aligned with the Gates MRI’s charitable mission to advance equitable access to lifesaving health technologies for populations most in need. In parallel, the company plans to advance large-scale manufacturing process development to enable affordable supply to low-resource settings, where RSV-associated infant mortality remains high. This approach reflects a balanced commitment to both generating commercial value in developed markets and the public health mission of SK bioscience to address unmet medical needs in resource-limited settings.

RSV is a leading cause of severe lower respiratory tract disease in infants and young children worldwide, with an estimated 100,000 deaths annually among infants under six months of age?a critical window targeted for protection by monoclonal antibodies. Approximately 97% of these deaths occur in low- and middle-income countries, reflecting the unequal global burden of RSV-related disease.

Global demand for RSV prevention continues to rise. According to Evaluate Pharma, the global market for RSV preventive antibodies is projected to reach 4.5 billion USD by 2032, with further growth expected as access expands beyond currently commercialized markets.

The World Health Organization (WHO), in its Global Market Study on RSV Immunization Products (2024), likewise noted that demand for RSV antibodies could increase sharply depending on affordability and inclusion in national immunization programs (NIPs), identifying the segment as a priority public-health market in the coming years.

Jaeyong Ahn, CEO of SK bioscience, said, “This newly in-licensed RSV preventive monoclonal antibody candidate is a strategic program that aligns public-health impact with commercial viability, and it will be a key priority for strengthening our portfolio competitiveness over the mid- to long- term. Going forward, we will continue to enhance our business capabilities and drive sustainable growth through technology-driven investment and expanded global partnerships.”

SK bioscience has a long commitment to advancing global public health. Beginning in 2013, SK received grant funding from the Gates Foundation to support the production and clinical development of affordable vaccines intended for use in low-income economies, including vaccines to prevent typhoid fever and COVID-19.