Sonoma Biotherapeutics Co-Founder Fred Ramsdell Awarded 2025 Nobel Prize in Physiology or Medicine for Pioneering FOXP3 Discovery and Advancing Treg Immunotherapy
Sonoma Biotherapeutics, Inc., a leading clinical-stage biotechnology company focused on developing engineered regulatory T cell (Treg) therapies for autoimmune and inflammatory diseases, proudly announced that its co-founder, past Chief Scientific Officer (CSO), and current chair of the Scientific Advisory Board, Fred Ramsdell, PhD, has been awarded the 2025 Nobel Prize in Physiology or Medicine. The recognition honors Dr. Ramsdell’s groundbreaking discovery of the FOXP3 gene, a pivotal finding that redefined the understanding of immune tolerance and opened a transformative era in immunotherapy.
A Landmark Discovery That Transformed Immunology
Dr. Ramsdell’s journey toward this historic achievement began decades ago, driven by a deep curiosity about the mechanisms that keep the immune system in balance. His pioneering research led to the identification of FOXP3, a gene whose mutations were found to cause devastating autoimmune diseases in mice and humans. This discovery provided the key to understanding the critical role of regulatory T cells (Tregs) — specialized immune cells that prevent the immune system from attacking the body’s own tissues.
By uncovering the molecular mechanisms that enable Tregs to suppress immune responses, Dr. Ramsdell and his collaborators laid the scientific foundation for a new therapeutic paradigm: restoring immune tolerance through Treg-based cell therapy. The FOXP3 gene became recognized as the “master regulator” of Treg development and function, a revelation that profoundly influenced immunology, autoimmunity research, and modern therapeutic design.
Celebrating a Lifelong Scientific Contribution
“Congratulations to Fred Ramsdell, co-founder of Sonoma Biotherapeutics and a valued friend and colleague,” said Jeff Bluestone, PhD, Chief Executive Officer and President of Sonoma Biotherapeutics. “Like many great scientists, Fred spent years working behind the scenes to identify the gene that caused devastating systemic autoimmune diseases in a little-known strain of mice. The discovery of FOXP3 changed our understanding of peripheral tolerance and led to an entirely new field of immunotherapy.”
Bluestone, himself a leading authority in immune tolerance and co-founder of the company, emphasized how Dr. Ramsdell’s dedication has inspired the next generation of scientists. “SonomaBio is proud to have had Fred as our previous Chief Scientific Officer and current advisor,” he added. “His seminal work—together with Alexander Rudensky, PhD, Sonoma co-founder and scientific advisor—has guided our development of Treg cell therapies. We are confident these therapies will revolutionize treatment for some of the most challenging autoimmune diseases.”
A Career Defined by Discovery and Leadership
Over nearly three decades, Dr. Fred Ramsdell has established himself as one of the foremost figures in immunology and biotechnology. His ability to connect fundamental biological insights with translational science has shaped the modern landscape of immune-based therapies.
After earning his doctoral degree in microbiology and immunology from the University of California, Los Angeles (UCLA) and a bachelor’s degree in biochemistry and cell biology from the University of California, San Diego (UCSD), Ramsdell pursued postdoctoral research at the National Institutes of Health (NIH). There, he began exploring the complex regulation of T cell activation and tolerance—an early focus that foreshadowed his Nobel-winning work.
Ramsdell’s professional trajectory spans leadership positions at several major biotechnology companies and research institutions:
- Immunex Corporation – He initiated studies on T cell activation and tolerance, emphasizing gene discovery and functional characterization.
- Darwin Molecular (acquired by Celltech R&D) – Here, Ramsdell led the team that identified and characterized FOXP3, a milestone that ultimately became the cornerstone of his Nobel Prize recognition.
- ZymoGenetics – Beginning in 2004, he directed programs investigating novel immune regulatory proteins with potential applications in autoimmune disease therapy.
- Novo Nordisk – In 2008, Ramsdell played a key role in establishing the company’s Inflammation Research Center in Seattle, leading the Immunobiology group to explore novel immune mechanisms relevant to chronic inflammatory disorders.
- Parker Institute for Cancer Immunotherapy (PICI) – As Chief Scientific Officer, Ramsdell helped shape the Institute’s early scientific direction, overseeing innovative programs in cancer immunology and immune regulation.
Through these experiences, Dr. Ramsdell cultivated a deep understanding of how immune pathways can be modulated to treat disease — a philosophy that now underpins Sonoma Biotherapeutics’ clinical vision.
A Scientific Vision Realized Through Sonoma Biotherapeutics
Founded by pioneers in immunology, including Drs. Fred Ramsdell, Alexander Rudensky, and Jeff Bluestone, Sonoma Biotherapeutics is dedicated to harnessing Treg cell therapy to restore immune balance in patients suffering from serious autoimmune and inflammatory diseases. The company’s mission directly builds upon the scientific legacy of FOXP3 and the field of Treg biology that Ramsdell helped create.
Sonoma’s platform combines cell engineering, precision gene editing, and proprietary manufacturing processes to generate highly stable, disease-targeted Treg therapies. These therapies are designed to suppress pathological immune responses without compromising the body’s ability to fight infections. By selectively re-establishing immune tolerance, Sonoma aims to transform the treatment landscape for conditions such as rheumatoid arthritis, multiple sclerosis, type 1 diabetes, and inflammatory bowel disease.
Bluestone noted that the company’s research culture is steeped in the same collaborative spirit that fueled Ramsdell’s discovery. “Fred and Alex Rudensky showed the world that fundamental curiosity-driven science can change medicine forever. Their work is the reason we now believe that precision-engineered Tregs can be the next revolution in immunotherapy,” he said.
A Legacy of Recognition and Impact
Dr. Ramsdell’s Nobel Prize marks a crowning achievement in a career already distinguished by prestigious honors. In 2017, he and Dr. Rudensky were jointly awarded the Crafoord Prize in Polyarthritis, a recognition often seen as complementary to the Nobel, for their contributions to understanding autoimmune diseases. The Nobel Committee’s selection in 2025 underscores the enduring global impact of their discovery.
Beyond the accolades, Ramsdell’s work has left an indelible mark on scientific thought and clinical innovation. His identification of FOXP3 not only explained the mechanisms underlying immune tolerance but also paved the way for targeted therapies that could one day replace systemic immunosuppression with more durable and precise interventions. Thousands of researchers and clinicians around the world now draw upon his findings in developing treatments for autoimmune disorders, transplantation tolerance, and even cancer.
Inspiring Future Generations of Scientists
The Nobel announcement serves as both recognition of the past and a call to the future. For Sonoma Biotherapeutics, it reaffirms the company’s role at the forefront of a field that bridges fundamental discovery and patient-centered innovation. For the global scientific community, Ramsdell’s achievement highlights the value of perseverance, curiosity, and collaboration in solving the immune system’s greatest mysteries.
In reflecting on Ramsdell’s contributions, Bluestone summed up the spirit of the company and its founder: “Fred’s work reminds us that transformative discoveries come from those willing to follow the science wherever it leads — even when the answers take years to reveal themselves. His discovery of FOXP3 didn’t just change immunology; it changed how we think about treating disease.”
About Sonoma Biotherapeutics
Sonoma Biotherapeutics is a clinical-stage biotechnology company developing engineered regulatory T cell (Treg) therapies aimed at restoring balance to the immune system and treating serious autoimmune and inflammatory diseases. Founded by leading experts in Treg biology and cell therapy, the company is leveraging proprietary technologies and platform approaches to develop a new generation of targeted, durable, and disease-modifying therapies. Headquartered in South San Francisco, California, with additional operations in Seattle, Washington, Sonoma Biotherapeutics represents a convergence of cutting-edge cell engineering and world-class immunology research.
For more information, visit sonomabio.com and follow the company on LinkedIn and X (formerly Twitter).
