Diamyd Medical: US Patent Allowance for Retogatein in Type 1 Diabetes Treatment

Stockholm, Sweden – February 9, 2026 – Diamyd Medical announced today that the United States Patent and Trademark Office (USPTO) has issued a Notice of Allowance for a patent covering a specific method for administering retogatein (rhGAD65) in the prevention and treatment of type 1 diabetes. This patent application centers on the intralymphatic administration of retogatein with alum, a method currently being utilized in the company’s ongoing Phase 3 clinical trial.

The allowed U.S. Patent is part of a broader international patent family, with existing rights already secured in Europe, Australia, Hong Kong, China, Canada, South Africa, Japan, Russia, and Israel. According to Diamyd Medical, this U.S. Patent, once granted, will significantly strengthen the company’s intellectual property position surrounding its antigen-specific immunotherapy platform. The patent is anticipated to be valid until 2035.

“This Notice of Allowance further strengthens our global intellectual property for our precision medicine and antigen-specific immunotherapy in type 1 diabetes,” stated Ulf Hannelius, President and CEO of Diamyd Medical. “Securing patent protection in the U.S. Is a key milestone as retogatein advances toward potential commercialization.”

Understanding Type 1 Diabetes and Retogatein

Type 1 diabetes is an autoimmune disease where the body’s immune system mistakenly attacks and destroys insulin-producing cells in the pancreas. This leads to a deficiency in insulin, a hormone crucial for regulating blood sugar levels. Currently, management of type 1 diabetes relies on lifelong insulin therapy. However, research efforts are focused on therapies that can preserve endogenous (naturally produced) insulin production and potentially delay or prevent disease progression.

Retogatein (rhGAD65) is an investigational antigen-specific immunotherapy developed by Diamyd Medical. It’s designed to induce immune tolerance to glutamic acid decarboxylase 65 (GAD65), a protein found in insulin-producing cells. The goal is to “re-educate” the immune system to stop attacking these cells, thereby preserving the body’s ability to produce insulin. Retogatein is formulated with alum, an adjuvant commonly used to enhance the immune response to vaccines and immunotherapies.

The Intralymphatic Administration Method

The patent application specifically covers the intralymphatic administration route. This involves delivering retogatein directly into the lymphatic system, a network of vessels that plays a critical role in immune function. The lymphatic system allows for direct exposure of the immunotherapy to immune cells, potentially enhancing its effectiveness. This method is currently being evaluated in the Phase 3 DIAGNODE-3 trial.

DIAGNODE-3 Trial and Future Prospects

The ongoing Phase 3 DIAGNODE-3 trial is a confirmatory study evaluating the efficacy of intralymphatic retogatein administration in children, adolescents, and adults recently diagnosed with Stage 3 type 1 diabetes. Stage 3 refers to clinically diagnosed, symptomatic type 1 diabetes. The trial is being conducted at 57 clinics across eight European countries and in the United States.

Diamyd Medical anticipates an interim efficacy readout from the DIAGNODE-3 trial, aligned with FDA requirements, by the end of March 2026. This readout will provide early insights into retogatein’s potential to preserve insulin production in newly diagnosed patients. The trial is specifically enrolling patients who carry the HLA DR3-DQ2 gene, a genetic marker present in approximately 40% of individuals with type 1 diabetes in Europe and the US.

Beyond patent protection, retogatein, as a biological product, is also eligible for regulatory market exclusivity in both the United States and Europe, contingent upon regulatory approval. This exclusivity provides a period of time during which competitors cannot market a similar product, even if they don’t infringe on the patent.

Orphan Drug and Fast Track Designations

Retogatein has received both Orphan Drug Designation and Fast Track Designation from the U.S. Food and Drug Administration (FDA) for the treatment of Stage 3 type 1 diabetes. Orphan Drug Designation is granted to therapies intended for rare diseases, providing incentives for development. Fast Track Designation is intended to expedite the development and review of drugs that address unmet medical needs. The FDA has also granted Fast Track Designation for the treatment of Stage 1 and 2 (pre-symptomatic) type 1 diabetes.

Manufacturing and Future Development

Diamyd Medical is currently developing a biomanufacturing facility in Umeå, Sweden, dedicated to the production of retogatein. The company also holds significant shares in NextCell Pharma AB, a stem cell company, and MainlyAI AB, an artificial intelligence company, suggesting a broader interest in innovative therapeutic approaches for diabetes and related conditions.

The granting of this Notice of Allowance represents a significant step forward for Diamyd Medical as it progresses towards potential commercialization of retogatein. The ongoing Phase 3 trial and anticipated data readout will be crucial in determining the future of this investigational immunotherapy for type 1 diabetes.