ai3Bio has emerged from stealth with $48 million in funding and a buzzing platform for targeting T cells in autoimmune disease.
The Massachusetts-based biotech is the product of Corner Therapeutics’ autoimmune technology splitting off and merging with the University of Pittsburgh-backed Novasenta. The funding was led by UPMC Enterprises and Ziff Capital Partners. They backed the complementary and foundational technology innovations from both Corner and Novasenta, which were combined to create ai3Bio, according to the company.
“We endeavor to be the first company to be able to deplete diseased T cells specifically,” said Jonathan Kagan, Ph.D., scientific co-founder of ai3Bio and professor at Harvard Medical School, in an interview with Fierce. “We want to use today's knowledge of our of inflammation to instruct tomorrow's drugs.”
ai3Bio is focused on targeting Th17-expressing diseased T cells. Th17 cells are a specialized subset of proinflammatory helper T cells. In autoimmune diseases, they can often be dysregulated and drive chronic inflammation and tissue damage.
The company is approaching Th17 cells using a different mechanism of action than other drugs on the market that revolve around this subset of cells, such as Novartis’ Cosentyx. That drug was developed to selectively bind and neutralize pro-inflammatory cytokine IL-17a, primarily produced by Th17 cells.
“Immunologically, the cytokine is the bullet, and the cell is the gun,” Kagan explained. “We want to take the take this gun out of the hands of the immune system when it's misbehaving.”
The company’s platform is a two-pronged artificial intelligence discovery platform paired with technology to eliminate Th17 cells: StarX and T Deplete. The StarX platform is a lipid nanoparticle delivery system with an mRNA payload directed to CD161, which is expressed on Th17 cells in autoimmune disease. The payload triggers cell death of the diseased Th17 cells by activating the cGAS-STING pathway.
This pathway acts as an alarm-activated kill switch, alerting the immune system to a foreign pathogen and initiating programmed cell death, or apoptosis.
The other part of ai3Bio’s platform, T Deplete, is a complementary approach that uses a targeting antibody to recruit the body's own immune cells to clear the same cells.
The company is emerging with an advisory board that houses immunologist Vijay Kuchroo, Ph.D., whose lab was the first to describe pathogenic Th17 cells, along with National Academy of Sciences members Ruslan Medzhitov, Ph.D., Alexander Rudensky, Ph.D., and Arlene Sharpe, M.D., Ph.D.
“We have a nice combination of events in a positive way, a perfect storm,” Kagan said. “The company is established in a well-oiled machine; the R&D is checking all the preclinical boxes along the way, and the community is starting to pay more attention and get more excited about what's next in cell therapy space.”
ai3Bio CEO Steven Altschuler, M.D., told Fierce that it is currently in another fundraising round with hopes to get assets to the clinic in 2027 or 2028. “The reception has been excellent. This is an approach that makes a lot of sense in an area where there's a real clinical need and there are not good therapies,” Altschuler said. “We've had both interests from investors and from a large biopharma as well.”
Big Pharma is no stranger to T-cell therapies for autoimmune disease. In June 2025, AbbVie bet $2.1 billion on Capstan Therapeutics to add an early-phase autoimmune drug candidate to its pipeline. A few months later, in October, Bristol Myers Squibb inked a $1.5 billion deal to acquire Orbital Therapeutics for its preclinical CD19 autoimmune program.