A Potent Bispecific

Pieris Pharmaceuticals’ leading immuno-oncology asset, cinrebafusp alfa (PRS-343), is a bispecific fusion protein that combines a 4-1BB-targeting Anticalin® protein and a HER2-targeting antibody. 4-1BB is an immunoreceptor that powerfully enhances T cell proliferation, survival, and activity. 

Cinrebafusp alfa bridges 4-1BB immune cells with HER2-expressing tumor cells, causing the immune cells to cluster around cancerous cells. By combining a 4-1BB-targeting Anticalin proteinwith a HER2-targeting antibody, cinrebafusp alfa focuses 4-1BB activation locally on the tumor, increasing the efficiency of the immune response and reducing systemic toxicity, compared to 4-1BB-targeting antibodies alone. 

Cinrebafusp alfa has shown both clinical benefit linked to a 4-1BB mechanism of action, and robust durability, and has been observed to be safe and well-tolerated at all doses and schedules tested.