March 2026 Research Update

This month adds an early step in treatment development rather than new evidence about benefit for people with Hunter syndrome. A Phase I study tested verenafusp alfa in healthy volunteers and found mostly mild, short-lived side effects, along with drug-level patterns in the blood that changed with dose. This kind of result is mainly about whether a new therapy can be given and how the body handles it, before it is studied in patients. [1]

In 20 healthy adult men who received a single intravenous dose, all completed the study and side effects were reported in 6 out of 20 participants. The reported side effects were described as mild and related to lab or test changes, with one case of increased bilirubin considered possibly related to the drug. The study also found that blood exposure to the drug rose with higher doses and that clearance slowed at higher doses, meaning the body removed the drug more slowly as the dose increased. [1]

For patients and caregivers, this is a sign that early-stage testing of a potential therapy is moving forward, but it does not tell us yet whether the drug helps Hunter syndrome symptoms or progression. Because the study was in healthy volunteers and used a single dose, it mainly helps clarify short-term tolerability and basic dosing-related drug behavior in the body. What remains uncertain is how these findings translate to repeated dosing, to children, and to people living with Hunter syndrome. [1]

This month also adds a new laboratory tool aimed at understanding different IDS gene changes that can cause Hunter syndrome. The study showed that an image-based cell test could consistently detect cell-shape and cell-structure differences across multiple IDS variants, and that patient-derived cells showed similar patterns. It also showed that adding recombinant IDS partly improved the cell findings, but did not fully reset all measured cell signals at the tested time points. [2]

Researchers created 12 genome-edited cell lines, each carrying a different IDS variant, and measured IDS enzyme activity alongside a single-score image readout of cell morphology (PathScoreLC). The different variants produced distinct biochemical activity levels and reproducible cell appearance patterns, and patient-derived lines matched those patterns. When recombinant human IDS was added, biochemical and cell-morphology measures improved only partly, and gene activity patterns (transcriptional changes) were not fully restored at the studied time points. [2]

For families, this is mainly early research that may matter later by improving how scientists study IDS variants and compare how different gene changes affect cells. It helps clarify that a measurable cell-appearance signature can track differences between variants and can also detect partial changes after adding recombinant IDS in the lab. What remains uncertain is how well this cell score predicts symptoms or treatment response in real people, and whether it can become a practical tool for diagnosis, prognosis, or treatment development. [2]