Eledon Reports Preliminary Data from First Six Patients with Type 1 Diabetes Treated with Tegoprubart as the Core Immunosuppressant Following Islet Transplantation in Investigator-Initiated Trial at UChicago Medicine

Eledon Pharmaceuticals, Inc. (“Eledon”) (NASDAQ: ELDN) today announced preliminary results from an investigator-initiated trial conducted at the University of Chicago Medicine’s Transplant Institute and presented at the Rachmiel Levine-Arthur Riggs Diabetes Research Symposium, held November 14-17, 2025 at City of Hope in Los Angeles, California.

The ongoing trial, which has been extended to include a total of 12 subjects, is evaluating tegoprubart, Eledon’s investigational anti-CD40 Ligand (anti-CD40L) antibody, as the core of a tacrolimus-free immunosuppression drug regimen for the prevention of islet transplant rejection in individuals with type 1 diabetes (T1D). The results, presented by Piotr Witkowski, M.D., Ph.D., Director of the Pancreas and Islet Transplant Program at UChicago Medicine, provide updated preliminary data on the first six subjects in the trial, demonstrating the ability of tegoprubart to prevent the rejection of transplanted islet cells in the absence of calcineurin inhibition resulting in sustained insulin-free management of hemoglobin A1C (HbA1c) in patients with T1D.

All six transplanted subjects demonstrated marked improvements in glycemic control, achieving and maintaining insulin independence after one or two islet transplants, primarily depending on the subjects’ body mass and baseline daily insulin requirements. The first three participants were transplanted over a year ago and have remained insulin-free, including a patient who has maintained stable blood glucose control reflected by an HbA1c as low as 4.7%, for over 15 months without the use of exogenous insulin. Two subsequent subjects transplanted in July 2025 achieved insulin independence within approximately four weeks following a single islet transplantation and have maintained an HbA1c below 6% for over 3 months. A sixth subject, who was transplanted in early August 2025, recently underwent a second islet infusion and is now insulin free with an HbA1c of 5.3%. All six patients have been free of severe hypoglycemic episodes since their transplants. Tegoprubart was generally well tolerated, with no reported serious infections, no thromboembolic or rejection events, and no signs of the kidney or neurological toxicity often observed with traditional calcineurin inhibitor-based immunosuppression.

“For years, clinicians have been working to find a new medication that can prevent rejection of islet cells while offering a better safety profile than calcineurin inhibitors including tacrolimus, which remain the current standard of care but are often associated with debilitating metabolic, neurologic, and cardiovascular toxicities,” said Dr. Witkowski. “These preliminary data in the first six subjects with T1D as part of our UChicago Medicine clinical trial are very encouraging, with all six subjects achieving insulin independence, and suggest that tegoprubart may be the innovative immunosuppression therapy we need to transform islet transplantation in the years ahead.”

“Breakthrough T1D continues to be encouraged by the data from the investigational use of tegoprubart as a novel immunosuppression alternative to advance islet transplantation,” said Esther Latres, Ph.D., Breakthrough T1D Senior Vice President, Research. “We look forward to continuing to support this promising research and to more data on tegoprubart in islet transplants in the future.”

This clinical trial is funded by Breakthrough T1D (formerly JDRF), with initial support from The Cure Alliance. Breakthrough T1D has also committed to fund a second study evaluating tegoprubart as part of a calcineurin inhibitor-free immunosuppression drug regimen to prevent islet transplant rejection in individuals with T1D and chronic kidney disease.

About Islet Transplantation for Type 1 Diabetes

Pancreatic islet transplantation is a minimally invasive procedure developed to provide blood glucose control for subjects with type 1 diabetes and minimize or eliminate dependence on insulin. During the procedure, pancreatic islets containing insulin-producing beta cells are isolated from the pancreas of a deceased organ donor and infused through a small catheter into the patient’s liver. The islet cells lodge in small blood vessels in the liver and release insulin. Post-procedure, subjects remain on immunosuppression therapy to prevent transplant rejection.

About Eledon Pharmaceuticals and tegoprubart

Eledon Pharmaceuticals, Inc. is a clinical stage biotechnology company that is developing immune-modulating therapies for the management and treatment of life-threatening conditions. The Company’s lead investigational product is tegoprubart, an anti-CD40L antibody with high affinity for the CD40 Ligand, a well-validated biological target that has broad therapeutic potential. The central role of CD40L signaling in both adaptive and innate immune cell activation and function positions it as an attractive target for non-lymphocyte depleting, immunomodulatory therapeutic intervention. The Company is building upon a deep historical knowledge of anti-CD40 Ligand biology to conduct preclinical and clinical studies in kidney allograft transplantation, xenotransplantation, and amyotrophic lateral sclerosis (ALS). Eledon is headquartered in Irvine, California. For more information, please visit the Company’s website at www.eledon.com .

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Forward-Looking Statements

This press release contains forward-looking statements that involve substantial risks and uncertainties. Any statements about the company’s planned clinical trials, the development of product candidates, expected or future results of tegoprubart trials and its ability to prevent rejection in connection with islet cell transplantation, as well as other statements containing the words “believes,” “anticipates,” “plans,” “expects,” “estimates,” “intends,” “predicts,” “projects,” “targets,” “looks forward,” “could,” “may,” and similar expressions, constitute forward-looking statements within the meaning of the Private Securities Litigation Reform Act of 1995. Forward-looking statements are inherently uncertain and are subject to numerous risks and uncertainties, including: risks relating to the safety and efficacy of our drug candidates; risks relating to clinical development timelines, including interactions with regulators and clinical sites, as well as patient enrollment; and risks relating to costs of clinical trials and the sufficiency of the company’s capital resources to fund planned clinical trials. Actual results may differ materially from those indicated by such forward-looking statements as a result of various factors. These risks and uncertainties, as well as other risks and uncertainties that could cause the company’s actual results to differ significantly from the forward-looking statements contained herein, are discussed in our quarterly 10-Q, annual 10-K, and other filings with the U.S. Securities and Exchange Commission, which can be found at www.sec.gov . Any forward-looking statements contained in this press release speak only as of the date hereof and not of any future date, and the company expressly disclaims any intent to update any forward-looking statements, whether as a result of new information, future events or otherwise.

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Investor Contact:

Stephen Jasper Gilmartin Group (858) 525 2047 [email protected]

Media Contact:

Jenna Urban CG Life (212) 253 8881 [email protected]

Source: Eledon Pharmaceuticals