Swedish Researchers Find Targeted Therapy Slows Blood Sugar Decline in Type 1 Diabetes

A study from Sweden, conducted by researchers at the prestigious Karolinska Institutet, has uncovered promising results for a targeted immunotherapy approach in young people recently diagnosed with Type 1 diabetes (T1D). The treatment — a drug called GAD-alum (Diamyd®) delivered directly into lymph nodes — may help preserve the body's remaining insulin-producing ability in patients who carry a specific genetic profile.

What the Swedish Researchers Did

The DIAGNODE-2 trial enrolled 109 patients aged 12 to 24 who had been recently diagnosed with T1D. All participants had detectable levels of GAD65 antibodies (a hallmark of autoimmune diabetes) and some remaining beta cell function, measured by fasting C-peptide levels above 0.12 nmol/L. Patients were randomly assigned to receive either three intralymphatic injections of GAD-alum plus daily oral vitamin D, or a placebo. Continuous glucose monitors (CGMs) tracked their blood sugar over 14-day periods at the start of the study, at 6 months, and at 15 months.

The research team focused special attention on participants carrying the HLA DR3-DQ2 genetic haplotype — a common genetic pattern that significantly raises the risk of developing Type 1 diabetes. Approximately 40–50% of people with T1D in the US and Europe carry this genetic variant, making these findings broadly relevant.

Key Findings — In Plain English

In the DR3-DQ2-positive group, patients who received GAD-alum maintained far better blood sugar control over 15 months compared to those on placebo. Here's what that looked like in practice:

• Time in Range (TIR): The target blood sugar range used in this study was 70–180 mg/dL (converted from 3.9–10 mmol/L). Treated patients lost only 5.1% of their time in this healthy range, while placebo patients lost 16.7% — a clinically meaningful difference (p=0.0075).
• High blood sugar spikes: Treated patients spent significantly less time above 250 mg/dL (converted from 13.9 mmol/L), meaning fewer dangerous highs (p=0.0036).
• Glucose Management Indicator (GMI): A CGM-based estimate of average blood sugar control also improved significantly in treated patients (p=0.0025).
• Glycemic variability: Blood sugar swings — a major quality-of-life concern — increased less in the treated group (p=0.0219).
• No increased low blood sugar risk: Importantly, the therapy did not increase episodes of hypoglycemia (below 70 mg/dL).

How This Compares to US Guidelines

The American Diabetes Association (ADA) currently recommends that T1D patients aim for at least 70% Time in Range (70–180 mg/dL). The fact that placebo patients lost nearly 17% of their TIR over just 15 months highlights how quickly control can deteriorate after diagnosis — and why preserving beta cell function matters so much early on. The ADA also now recognizes CGM as the standard of care for T1D monitoring, making these CGM-based findings directly applicable to US patients.

Why This Matters for US Patients

Most current T1D treatments manage symptoms — they don't address the underlying autoimmune attack that destroys insulin-producing beta cells. GAD-alum represents a fundamentally different approach: training the immune system to stop attacking itself. For the estimated 1.6 million Americans living with Type 1 diabetes, a therapy that slows disease progression — especially in those with a specific genetic profile — could mean fewer complications, less insulin dependence over time, and better quality of life. While GAD-alum is not yet FDA-approved, this Phase 2b data brings it closer to larger trials. US patients with T1D, especially those newly diagnosed, may want to ask their endocrinologist about HLA genetic testing and eligibility for upcoming clinical trials.

Study Citation

Nowak, Lind, Sumnik et al. "Intralymphatic GAD-Alum (Diamyd®) Improves Glycemic Control in Type 1 Diabetes With HLA DR3-DQ2." The Journal of Clinical Endocrinology & Metabolism, 2022. PMID: 35665810. DOI: 10.1210/clinem/dgac343