ISR Immune System Regulation Holding AB (publ) (ISR.ST) is a Sweden-based biotechnology company focused on developing immunostimulatory drugs and innovative inhaled vaccines targeting chronic infectious diseases including HIV, hepatitis B (HBV), and COVID-19, as well as oncology indications; its pipeline features candidates such as ISR048 and ISR049 for HIV treatment, ISR050 with immunostimulatory properties explored in chronic infection models like tuberculosis, a spray-dried nasal powder vaccine formulation for SARS-CoV-2 and variants, and broader platforms for respiratory viral infections and cancer immunotherapies. Founded in 2007 and headquartered in Solna, Sweden, near Karolinska Hospital, the company operates primarily in Europe with a small team of approximately five employees led by CEO Ola Winqvist, emphasizing preclinical and clinical research to advance immunotherapy solutions for global markets. Recent developments include signing development agreements with Catalent in 2022 to scale up its spray-dried nasal COVID-19 vaccine powder for phase trials, though partnerships such as with Iconovo for the ICOone inhalator platform were terminated in September 2024 due to payment issues allowing ISR to refocus resources, alongside ongoing efforts in vaccine pipeline expansion against multiple viral threats.