Diamyd Speeds Up Pivotal Type 1 Diabetes Trial After FDA Pact

STOCKHOLM, SWEDEN – December 29, 2025 – In a significant development for the treatment of type 1 diabetes, Diamyd Medical announced today it has reached an agreement with the U.S. Food and Drug Administration (FDA) to accelerate its pivotal Phase 3 trial. The primary efficacy results for DIAGNODE-3, a registrational study of the company's investigational therapy Diamyd®, will now be available nine months earlier than originally planned, a move that could dramatically shorten the timeline to potential market approval.

Following a recent Type C meeting with the agency, the primary efficacy readout will now be assessed at 15 months post-treatment instead of the previous 24-month mark. This change aligns with recent FDA guidance and provides a clearer, faster route to evaluating the therapy's effectiveness in newly diagnosed patients. The decision injects a new sense of urgency and optimism into the quest for a therapy that can preserve the body's own insulin-producing capabilities.

"We are very pleased with the FDA's feedback as it provides a clear way forward," said Ulf Hannelius, CEO of Diamyd Medical, in a statement. "The proposed change meaningfully shortens the timeline to the full primary efficacy readout in our registrational Phase 3 trial, while maintaining a robust assessment of long-term efficacy."

A Faster Path to Key Data

The core of the trial's acceleration lies in the adjustment of its primary endpoints. The study is designed to measure two key markers: C-peptide area under the curve (AUC), which is a reliable indicator of the body's endogenous insulin production, and HbA1c, a standard measure of long-term blood sugar control. While initially slated for a 24-month assessment, the FDA has agreed that a 15-month analysis will be sufficient for the primary evaluation of efficacy.

This modification, which will be formalized in a protocol amendment, does not discard the long-term view. The original 24-month assessment will be retained as a critical secondary endpoint, allowing researchers to evaluate the durability of Diamyd®'s treatment effect over a more extended period. This dual approach balances the need for speed with the scientific rigor required to understand the therapy's long-term impact.

Even before the full 15-month data becomes available, the company is on track for another major catalyst. An interim efficacy readout, involving approximately 170 of the trial's participants, is still scheduled for the end of March 2026. According to the company, this interim analysis may be sufficient to support an accelerated Biologics License Application (BLA) pathway, potentially bringing the therapy to patients even sooner.

Precision Medicine for an Autoimmune Disease

DIAGNODE-3 is a randomized, double-blind, placebo-controlled Phase 3 trial, the gold standard in clinical research. It aims to enroll approximately 300 individuals recently diagnosed with Stage 3 type 1 diabetes. What sets this trial apart is its focus on a specific, genetically defined population.

Diamyd® is an antigen-specific immunotherapy designed to halt the autoimmune attack that characterizes type 1 diabetes. The therapy works by introducing a modified form of the GAD65 protein, an autoantigen that the immune system mistakenly targets, to retrain the body's defenses and preserve the function of remaining insulin-producing beta cells. Crucially, the therapy has shown the most promise in individuals who carry a specific genetic marker known as HLA DR3-DQ2.

This genetic profile is common, found in approximately 40% of all patients with type 1 diabetes in Europe and the United States. By exclusively recruiting this patient subgroup for the DIAGNODE-3 trial, Diamyd Medical is employing a precision-medicine strategy, aiming to deliver the right treatment to the right patients. This targeted approach is built on a foundation of previous research, including a large-scale meta-analysis and a European Phase 2b trial, which both demonstrated significant results in preserving insulin production within this specific genetic group.

Navigating a Favorable Regulatory Landscape

The acceleration of the trial timeline is the latest in a series of positive regulatory developments for Diamyd Medical. The FDA has already granted the therapy significant support, recognizing its potential to address a major unmet medical need.

Diamyd® holds Fast Track Designation for all three stages of type 1 diabetes, a status designed to facilitate the development and expedite the review of drugs that treat serious conditions. It has also been granted Orphan Drug Designation in the U.S. for Stage 3 type 1 diabetes, providing incentives to encourage the development of drugs for rare diseases.

Perhaps most importantly, the FDA has confirmed that C-peptide is an acceptable surrogate endpoint that may support an accelerated approval pathway. This means that a demonstrated ability to preserve C-peptide levels—proving the preservation of insulin production—could be enough for an initial approval, with long-term clinical outcomes confirmed later. This combination of designations creates a highly supportive regulatory environment for the therapy's development.

As the DIAGNODE-3 trial continues to actively recruit patients across 57 clinics in Europe and the U.S., the company is also looking ahead. A biomanufacturing facility is under construction in Umeå, Sweden, to produce the recombinant GAD65 protein, the active ingredient in Diamyd®. This investment signals the company's confidence in the therapy and its commitment to being prepared for commercial-scale production should the trial prove successful.