Jade Biosciences Announces Appointment of Mark Eisner, M.D., M.P.H., to Board of Directors (Form 8-K)

Jade Biosciences Announces Appointment of Mark Eisner, M.D., M.P.H., to Board of Directors

San Francisco and Vancouver, British Columbia, June 26, 2026 - Jade Biosciences, Inc. (the "Company" or "Jade") (Nasdaq: JBIO), a clinical-stage biotechnology company focused on developing best-in-class therapies for autoimmune diseases, today announced the appointment of Mark Eisner, M.D., M.P.H., to its Board of Directors, effective June 25, 2026.

"We are pleased to welcome Dr. Eisner to the board," said Tom Frohlich, Chief Executive Officer of Jade Biosciences. "Mark's biopharmaceutical executive experience and proven track record guiding innovative therapies from early clinical development through regulatory approval and global commercialization will be highly valuable as Jade rapidly advances its pipeline of antibody-based therapies for autoimmune diseases."

Dr. Mark Eisner, M.D., M.P.H., has more than 25 years of leadership in clinical development and immunology. He most recently served as Executive Vice President and Chief Medical Officer of Vir Biotechnology, where he oversaw clinical development, regulatory sciences, and medical affairs. Previously, he served as Chief Medical Officer at Sonoma Biotherapeutics and FibroGen, and spent nearly 11 years at Genentech/Roche, including as Senior Vice President and Global Head of Product Development for Immunology, Infectious Disease, and Ophthalmology. In that role, he led multinational development programs and global regulatory submissions across major therapeutic areas. Prior to entering industry, Dr. Eisner was Professor of Medicine and Anesthesia at the University of California, San Francisco.

"I am excited to join the Board of Directors at Jade as the Company rapidly advances its portfolio of potential best-in-class therapies for multiple autoimmune diseases," said Dr. Eisner. "Jade is well-positioned to address areas of substantial unmet need for patients, and I look forward to contributing as a board member to support the impact."

About Jade Biosciences, Inc.

Jade Biosciences is a clinical-stage biotechnology company focused on developing best-in-class therapies that address critical unmet needs in autoimmune diseases. Jade's lead candidate, JADE101, targets the cytokine APRIL, and is currently being evaluated for the treatment of immunoglobulin A nephropathy. Jade's pipeline also includes JADE201, an afucosylated anti-BAFF-R monoclonal antibody, as well as JADE301, an undisclosed antibody program. Jade was launched based on assets licensed from Paragon Therapeutics, an antibody discovery engine founded by Fairmount. For more information, visit JadeBiosciences.com and follow the Company on LinkedIn.