May 2026 Research Update

This month added more real-world evidence that enzyme replacement therapy (ERT) in Pompe disease is linked to better survival, while showing that different body systems may respond differently. In infants, heart measurements improved over the first year on ERT and survival looked better than without ERT. In adults with late-onset Pompe disease, survival also looked better in people who received ERT, and a small subgroup suggested earlier start may align with better walking and hip strength over time. [1] [2]

In infantile-onset Pompe disease, a single-center cohort reported that after 12 months of alglucosidase alfa (ERT), heart structure measurements decreased and NT-proBNP (a blood marker related to heart strain) changed at follow-up. Survival also differed across groups, with fewer deaths reported in the ERT group than the non-ERT group, while all patients in the gene therapy group in this cohort were reported alive during the study period. The same report noted that motor progress was mixed at longer follow-up, with most but not all children gaining milestones. [1]

In late-onset Pompe disease, a retrospective cohort from one Chinese center reported lower mortality in people who received ERT than those who did not, but the authors emphasized that the study design and access-to-treatment factors can bias this type of comparison. In a very small timing subgroup, people who started ERT within 1 year were reported to have better change over time in a walking test and iliopsoas (hip) strength than those who started later, but the numbers were too small to be confident this would hold up in other groups. This study also described muscle biopsy patterns and suggested glycogenin could be an early tissue marker, with other cell stress markers appearing later. [2]

For families, these studies strengthen a practical picture that ERT is often linked with longer survival in both infantile-onset and late-onset Pompe disease, based on routine-care data rather than a randomized trial. They also help set expectations about what improvements may look like: heart changes in infants were more clearly measured, while muscle and daily-function changes were more variable and sometimes limited. What remains uncertain is how much of the survival difference in the adult cohort is due to ERT itself versus differences between people who did or did not receive treatment, and whether starting earlier reliably leads to better function in larger groups. [1] [2]

This month included early research on tests that might help measure Pompe disease activity or treatment response, but the work is not yet at the point of predicting how someone will feel or function. One human study showed that antibodies against the enzyme used in ERT clearly separated treated late-onset Pompe patients from healthy people, but did not match motor function levels in that small sample. A separate mouse study reported that a specialized MRI approach produced signals that tracked muscle glycogen levels, raising the possibility of non-invasive glycogen monitoring in future research. [3] [4]

In a small case-control study of adults with late-onset Pompe disease on ERT, anti-rhGAA (anti-enzyme) antibodies were higher than in matched healthy controls, and the lab methods agreed well with each other. However, antibody levels were not significantly related to motor function grading in this dataset, which may reflect limited sample size or a true lack of connection. The main message is that antibody tests can confirm an immune response to ERT, but this study did not show they can explain differences in physical function. [3]

In a Pompe mouse model, researchers compared affected mice with healthy controls and found much higher muscle glycogen on lab testing in the Pompe mice. MRI signals designed to be sensitive to glycogen and related tissue effects correlated with the measured glycogen levels, suggesting the imaging readouts were capturing real storage differences. Because this was animal research using high-field MRI equipment, it mainly supports future tool development rather than providing a test ready for routine patient care. [4]

For patients and caregivers, these studies mainly add to research aimed at better tracking of Pompe disease rather than changing care today. Antibody testing may matter now in understanding immune responses to ERT, but this small study did not show that higher antibody levels translated into worse motor ability. The mouse MRI work matters later if it can be adapted to people, because a non-invasive way to estimate muscle glycogen could reduce reliance on more invasive measures, but that step was not tested here. [3] [4]

These studies expanded the picture beyond muscle weakness by looking at broader health risks and uncommon complications linked to newer or ongoing treatments. In a matched comparison, adults with late-onset Pompe disease had higher levels of several cardiovascular risk factors than similar people without Pompe, although differences in actual cardiovascular events were not statistically clear. Two individual case reports described significant treatment-related problems: severe allergic reactions to ERT that were eventually managed with an add-on medicine, and a sensory nerve problem after investigational AAV gene therapy. [5] [6] [7]

In the matched cohort study, adults with late-onset Pompe disease had a higher resting heart rate and higher measures related to abdominal weight distribution than controls, and a history of hypertension was more common. The study also reported more cardiovascular events in the Pompe group than controls, but this difference was not statistically significant, which the authors noted may relate to limited power because events were not frequent. In plain language, the risk-factor signals looked clearer than the event signals in this dataset. [5]

Across the 2 case reports, the shared message is that immune and nerve-related side effects can occur and may require specialized evaluation. One report described a woman with late-onset Pompe disease who had IgE-mediated hypersensitivity to ERT, where desensitization alone was only temporarily effective and adding omalizumab allowed safe reintroduction with gradual dose escalation and improved quality of life. Another report described a woman who developed sensory neuronopathy after intravenous AT845 (investigational AAV gene therapy), with partial improvement after corticosteroids but incomplete resolution after 1 year. [6] [7]

For day-to-day life, the cardiovascular study suggests it may be useful for research and long-term planning to pay attention to common heart-risk factors in late-onset Pompe disease, even though this study could not clearly prove a difference in cardiovascular events. The case reports do not describe what most people will experience, but they help document what is possible and how it was handled in individual patients, which can support future safety monitoring and research. What remains uncertain is how often these complications occur across larger groups, and which patient factors raise or lower the chance of experiencing them. [5] [6] [7]