ai3Bio Raises $48 Million Series A to Develop Th17-Targeting Autoimmune Therapies

ai3Bio, a Pittsburgh- and Watertown-based biotechnology startup, has raised $48 million in a Series A venture round to advance medicines that "reset" the immune systems of patients with autoimmune diseases, the company announced on September 29, 2026. The startup was assembled from assets of two biotechs: Corner Therapeutics and Novasenta, a cancer immunology company spun out of the University of Pittsburgh Medical Center. Harvard pediatrics professor Jonathan Kagan serves as scientific founder, while former Children's Hospital of Philadelphia CEO Steven Altschuler is chief executive. Rather than pursue B cell-depleting cell therapies, ai3Bio targets Th17 cells implicated in inflammatory skin and gut disorders. Its two preclinical approaches—lipid nanoparticle-delivered self-destruct instructions and a targeted antibody—preserve the broader immune system. Early safety studies supporting a human trial application are underway; lead indications were not disclosed. UPMC Enterprises and Ziff Capital Partners led the round, joined by Cockrell Partners and Tanis Ventures. Alnylam Pharmaceuticals CEO John Maraganore is a strategic advisor.