2nd June 2026 Dr. Michael Rosenblum leading University of California (UCSF) immunologist and dermatologist appointed to Immuthera Scientific Advisory Board June 1, 2026 – Immuthera, the USA subsidiary of PolTREG S.A., an emerging leader in engineered T regulatory (CAR-Treg) cell therapies, today announced the appointment of renowned dermatologist and immunologist Michael Rosenblum, M.D., Ph.D., to its Scientific Advisory Board (SAB). Dr. Rosenblum will help guide the clinical advancement of Immuthera’s first-in-class CD6/CTLA4 CAR-Treg platform as it relates to the development of this therapy in severe dermatological and related autoimmune and inflammatory diseases. Dr. Rosenblum is a Professor in the Department of Dermatology at the University of California, San Francisco (UCSF) and is widely recognized as one of the world’s leading skin immunologists and Treg biologist. His pioneering laboratory research has deeply illuminated how regulatory T cells (Tregs) are distributed and operate in peripheral tissues—particularly the skin. His work established that Tregs are heavily localized in barrier tissues like skin and the GI tract, where they are critical not only for immunosuppression but also for tissue repair, epithelial regeneration, and controlling fibrosis. Over his distinguished career, Dr. Rosenblum’s translational achievements have been recognized with highly prestigious honors, including the Burroughs Wellcome Fund Career Award for Medical Scientists and the NIH Director’s New Innovator Award. A successful biotech entrepreneur, he is also the scientific co-founder of Delinia Bio (acquired by Celgene) and co-founded TRex Bio, Sitryx Bio and Radera Therapeutics. He will now bring his profound understanding of tissue-resident Tregs and autoimmune disease to Immuthera’s SAB. “Immuthera’s CD6/CTLA4 CAR-Treg platform represents a true paradigm shift in targeted cellular therapy,” said Dr. Rosenblum. “By combining CD6 targeting with a Treg-specific CTLA4 signaling domain, the company is addressing the root causes of autoimmune and inflammatory conditions right at the tissue level. I am excited to join the Scientific Advisory Board and work alongside this exceptional team to bring these life-changing therapies to patients.” Immuthera’s trailblazing CAR-Treg is the first to target autoreactive T-cells and the first to utilize the potent, Treg-specific CTLA4 signaling domain to improve cell function and create a highly localized immunosuppressive microenvironment. The therapy has already demonstrated safety and achieved compelling early clinical signs of efficacy in patients with skin and joint involvement in a Phase I study of patients suffering from chronic Graft versus Host Disease (cGVHD – Oral presentation at ASH December 2025). An IND for a Phase 1 Safety study in Stage 3 Type 1 Diabetes was authorized in December 2025 and is now recruiting. The company is considering a basket study in dermatological and neuroinflammatory autoimmune diseases. The CD6/CTLA4 CAR-Treg is truly a “Pipeline in a Product”. “We are honored to welcome Dr. Rosenblum to our Scientific Advisory Board,” said Professor Piotr Trzonkowski, MD, Chief Executive Officer of Immuthera and parent company PolTREG. “Dr. Rosenblum’s groundbreaking insights into how Tregs control immune responses in skin are unmatched. His expertise will be invaluable as we accelerate the clinical development of our CD6/CTLA4 CAR-Tregs in dermatological autoimmune diseases in parallel to our efforts in neuroinflammatory autoimmune diseases and Type 1 Diabetes.” Immuthera’s SAB also consists of: · Dr. Jay Skyler, Professor of Medicine, Pediatrics, & Psychology, Division of Endocrinology Diabetes & Metabolism, Department of Medicine, Leonard M. Miller School at the University of Miami. · Dr. Desmond Schatz, Professor of Pediatrics, Medical Director of the Diabetes Institute and Director of the Clinical Research Center at the University of Floriday, Gainesville. · Dr. Lawrence Steinman, George A. Zimmermann Professor and Professor of Pediatrics. Professor of Neurology and Neurological Sciences, Pediatrics, and Genetics. Stanford University. · Dr. Antoinette Moran is the Marguerite & James Dugger Professor in Pediatrics, Division of Pediatric Endocrinology in the Department of Pediatrics Division of Endocrinology and Diabetology at the University of Minnesota. · Dr. Jason Gaglia, MMSC, is an Assistant Professor of Medicine: Harvard Medical School, an Attending Physician at the Joslin Diabetes Center and Beth Israel Deaconess Medical Center, the Director of the Hood Center for the Prevention of Childhood Diabetes at Joslin, and a Principal Investigator at the Joslin Diabetes Center affiliated with Harvard Medical School. · Dr. Jeffrey Cohen, is Professor of Neurology in the Cleveland Clinic Lerner college of Medicine, holds the Hazel prior Hostetler Endowed Chair, and is the Director of the Neuroimmunology Fellowship program. About Immuthera: Immuthera is advancing the first-in-class CD6/CTLA4 CAR-Treg (licensed from City of Hope) in North America. The CD6/CTLA4 CAR-Treg is the first T-cell directed CAR-Treg and the first to have a Treg specific signaling domain to improve cell function in-vivo. This asset has been evaluated in an initial Phase I study of 6 patients with chronic Graft Versus Host Disease up to 2 years with excellent safety and strong initial efficacy signals. A second IND has been approved for a Phase I study in Stage 3 T1D. Immuthera will expand into dermatological and neuroinflammatory autoimmune diseases through Phase I Basket studies. Immuthera will have full access to PolTREG’s Research and Development capabilities, asset pipeline, and low COGS cell therapy manufacturing centre in Gdansk. Immuthera is currently seeking investment to pursue the clinical development of this asset in the United States. More information at: https://immuthera.bio/ About PolTREG: PolTREG is a global leader in developing autoimmune therapies based on T-regulatory cells (Tregs). Its lead product, PTG-007+Rituximab, is an autologous Treg treatment for stage 3, early-onset Type-1 Diabetes (T1D) where the company is filing for an EMA Marketing Authorization Approval. A Phase II/III study in presymptomatic stage 1 children, as young as 3, is currently ongoing. PolTREG has established a robust and diverse platform of cell therapy approaches, including CAR-TREG, multi-edited, allogeneic CAR-Tregs, and In-vivo Antigen-Specific Tregs for T1D and neuroinflammatory autoimmune diseases. More information at: https://poltreg.bio/ For additional information please contact: Media contact: Michał Wierzchowski, cc groupTel.: +48 531 613 067michal.wierzchowski@ccgroup.pl Contact for investors: ir@poltreg.com Agata Dzięciołowska, cc groupTel.:+48 606 205 119agata.dzieciolowska@ccgroup.pl