ai3Bio, a biotechnology company focused on treating autoimmune disease at its cellular source, has officially launched with US$48 million in Series A funding. The company, based in Watertown, Massachusetts, announced that the financing was led by founding investors UPMC Enterprises and Ziff Capital Partners, with additional support from Cockrell Interests and Tanis Ventures. The capital will fund preclinical and IND-enabling studies designed to advance two proprietary therapeutic platforms toward first-in-human trials in autoimmune disease.
A Root Cause Strategy for Autoimmune Disease
Current autoimmune therapies often suppress the immune system broadly, leaving disease-causing cells untouched and patients vulnerable to relapse. Many newer in vivo approaches target B cells through indirect, multi-step processes rather than addressing the T cells that drive inflammation. ai3Bio aims to reset the immune system by directly targeting and eliminating disease-causing Th17 cells in vivo, in a single step, while preserving broader immune function.
Two Complementary Platforms
ai3Bio is advancing two platforms built around this mechanism: STARx and T Deplete. STARx uses a lipid nanoparticle to deliver messenger RNA that triggers a targeted anti-inflammatory self-destruct process in disease-causing Th17 cells. T Deplete uses a targeting antibody to recruit the body’s own immune cells to clear the same pathogenic population.
Preclinical Validation
Preclinical evidence supports the therapeutic potential of both STARx and T Deplete. Blood samples from patients with autoimmune disease demonstrated that the lipid nanoparticle technology effectively removed disease-causing Th17 cells. The antibody platform also showed potent efficacy in a non-human primate model, with IND-enabling safety studies now underway and additional work planned to support first-in-human trials.
Leadership and Scientific Advisory Board
ai3Bio is led by Chief Executive Officer Steven Altschuler, M.D., alongside Scientific Co-founder Jonathan Kagan, Ph.D., Chief Technology Officer Michael Lyman, Ph.D., and Chief Financial and Business Officer Nick Seaver. The company has also assembled a scientific advisory board that includes Alnylam Pharmaceuticals founding CEO John Maraganore, Ph.D., and immunologists Vijay Kuchroo, DVM, Ph.D., Ruslan Medzhitov, Ph.D., Alexander Rudensky, Ph.D., and Arlene Sharpe, M.D., Ph.D. This group brings deep experience in drug discovery, immunology, and the clinical development of novel therapies.
Investor Confidence and Market Context
The global market for autoimmune disease treatment has surpassed US$130 billion, yet millions of patients continue to cycle through therapies that manage symptoms without delivering lasting remission. More than 15 million Americans live with autoimmune diseases, and current treatments often leave the underlying disease-causing cells untouched. ai3Bio’s investors argue that the company’s ability to combine artificial intelligence-enabled discovery with precise in vivo biology could create disease-modifying therapies across a broad range of autoimmune conditions.
Strategic Vision and Support
Fabian Tenenbaum, Executive Vice President at UPMC Enterprises and Board Chair at ai3Bio, said the company represents a fundamentally new approach by targeting pathogenic cells that drive disease rather than suppressing symptoms. He added that pairing AI-enabled discovery with precise in vivo biology gives the platform the potential to improve the lives of millions of patients. UPMC Enterprises and Ziff Capital Partners backed the foundational technology innovations that were combined to create ai3Bio.
With US$48 million in Series A funding and a leadership team with deep biotechnology experience, ai3Bio is positioning itself to advance a new class of autoimmune therapies. The company’s dual platform strategy reflects a broader shift in immunology toward selective immune reset rather than broad immunosuppression. If successful in clinical testing, this approach could offer patients a path toward lasting remission and fundamentally change the management of autoimmune disease.