Our Team

  • Jeffrey Millman | CEO and Co-Founder

    Jeffrey Millman, PhD, is a bioengineer and stem cell biologist trained at MIT and Harvard, and now a tenured Full Professor at Washington University School of Medicine. With more than two decades of stem cell experience and fifteen years dedicated to diabetes research, he is driven by a deep passion for developing transformative therapies for the diabetes community. Dr. Millman developed the original stem cell–derived islet (SC-islet) technology at Harvard that became the foundational IP for Semma Therapeutics—acquired by Vertex Pharmaceuticals for $950M and now in Phase 3 clinical trials—as well as a next-generation platform licensed to Sana Biotechnology, where he later served as Research Lead and VP of Research. Building on this legacy, he co-founded IsletForge Innovations to advance his newest SC-islet technology and bring next-generation, life-changing treatments to patients.

  • Steven Kattman | CSO and Co-Founder

    Steven Kattman, PhD, is an immunologist with postdoctoral training in developmental biology, bringing two decades of stem cell expertise and 15 years of biotech and pharmaceutical industry experience. Over more than a decade in leadership roles spanning Research, CMC, and Program Leadership, Dr. Kattman became a pioneer in developing the first manufacturing technologies to produce pluripotent stem cell–derived cell types as commercial products. He has published over 20 peer-reviewed papers, holds five patents in the stem cell field, and spent two years partnering closely with Dr. Jeff Millman as Islet Cell Program Lead at Sana Biotechnology. Building on his track record of translating stem cell science into real-world therapies, he now brings his leadership and technical vision to IsletForge Innovations to help drive next-generation islet therapies toward patients.

  • Nathaniel Hogrebe | VP and Scientific Co-Founder

    Nathaniel Hogrebe, PhD, is a biomedical engineer with a B.S. in Chemical Engineering from the University of Dayton and M.S./Ph.D. training from The Ohio State University, specializing in stem cells and directed differentiation. With 15 years of experience in stem cell engineering, he has contributed extensively to advancing stem cell–derived islet (SC-islet) technologies through his work as a postdoctoral researcher and as an Instructor at Washington University School of Medicine. Dr. Hogrebe has developed multiple next-generation SC-islet protocols and technologies, resulting in several patents and nine peer-reviewed publications in high-impact journals, including Nature Biotechnology. One of these patented innovations was licensed to Sana Biotechnology and became foundational to their diabetes program. He now brings this deep technical expertise to IsletForge Innovations to help accelerate breakthrough islet therapies.