July 2026 Research Update

This month, studies in adults with late-onset Pompe disease focused on what happens when enzyme therapy is adjusted over time, especially when people worsen on alglucosidase alfa. Across real-world reports, the clearest signal was in walking ability, which tended to stabilize or improve after a switch to avalglucosidase alfa, while breathing test results were more likely to stay similar over the first 1 to 2 years. [1]

In the French Pompe registry, adults who switched because they were doing poorly on alglucosidase alfa had a change in their walking test trend, with a decline before switching and stabilization or improvement in the first year after switching. By the second year, the average walking change was less clear, and breathing measurements did not show a clear improvement over 1 to 2 years. The same registry analysis reported that younger age at switch, higher body mass index, and greater decline before switching were linked with better motor response after switching. [1]

A separate chart review from India also painted a mixed, real-world picture for adults receiving enzyme replacement therapy, with some people showing stabilization on walking tests and others worsening, including some loss of independent walking over follow-up. For breathing, the small group with before-and-after test data split between those who declined and those who stayed stable, and a few developed sleep-related breathing problems that required nighttime breathing support. A small number of patients switched from alglucosidase alfa to avalglucosidase alfa, and limited data suggested some breathing-test improvement after switching in some individuals. [2]

One modeling study compared long-term outcomes for cipaglucosidase alfa plus miglustat (a newer enzyme therapy plus an add-on medicine) versus alglucosidase alfa in adults with late-onset Pompe disease. The model predicted slower progression with cipaglucosidase alfa plus miglustat, including more years without needing mobility or breathing support, and longer time spent with wheelchair dependence or invasive breathing support in the alglucosidase alfa group. Because this is a simulation built from earlier studies and registry information, it is an estimate rather than a direct head-to-head patient comparison. [3]

For patients, this month adds detail about what may happen in routine care when a person with late-onset Pompe disease is not doing well on one enzyme therapy and changes to another. The most consistent real-world finding here was that walking ability may be more likely to stabilize in the first year after switching to avalglucosidase alfa, while breathing measures may not change much over the same time window. It remains uncertain how long any walking benefit lasts for many people, and how well modeled predictions for cipaglucosidase alfa plus miglustat match what individuals will experience in everyday care. [1]

These studies also highlight that day-to-day outcomes can vary widely between individuals, even when people receive the same type of enzyme therapy. Some adults showed stability while others declined, and sleep-related breathing issues appeared in a subset, which is a reminder that Pompe disease can affect breathing in ways that are not always captured by a single clinic breathing test. Because the evidence here comes from observational reports and modeling, it mainly adds context for understanding expected ranges of response rather than providing definitive comparisons between treatments. [2]

This month also added practical information about living with Pompe disease that goes beyond which drug is used: how treatment is delivered and how muscle health might be tracked. A large pediatric experience suggested that home enzyme infusions can be carried out with manageable infusion reactions, and an exploratory study suggested a painless electrical muscle measurement may reflect muscle changes and everyday function. Together, these studies point toward care that is both more home-centered and more measurable, while still needing confirmation in different settings. [4] [5]

In the Netherlands, a long-running pediatric cohort compared hospital-based and home-based infusions of recombinant human alpha-glucosidase (rhGAA), the enzyme replacement used in Pompe disease. Infusion-associated reactions were reported less often at home than in the hospital, and severe reactions were uncommon in both settings; all reactions were reported as manageable. Most reactions occurred in children with classic infantile Pompe, which helps clarify which group contributed most to the reaction counts in this dataset. [4]

A separate observational study evaluated electrical impedance myography, a quick, noninvasive way to measure how muscles conduct a small electrical signal. People with Pompe disease had lower values than healthy controls, with the biggest differences reported in infantile and pediatric Pompe, and lower measurements lined up with more muscle fat on imaging and worse motor performance. Participants with Pompe disease also reported more problems with pain, mobility, stress, and physical function, linking these measurement differences to aspects of daily life. [5]

For families, the home-infusion report may matter now because it describes real-world experience with where infusions happen and what reactions looked like, with fewer infusion reactions reported at home in this dataset. It does not prove that home infusion is safer for every child, since this depends on having appropriate infrastructure and clinical support, but it helps make the range of observed risks more concrete. [4]

The muscle measurement study may matter more for the future, because it suggests a possible way to track muscle health without a scan or a biopsy. If confirmed in larger and longer studies, this type of test could potentially make it easier to follow changes over time and relate them to function, but the current evidence is an early snapshot rather than proof that it predicts long-term outcomes. [5]

Two animal studies reported encouraging effects of very early (newborn) systemic gene therapy on heart-related outcomes in Pompe disease models. The shared picture is stronger improvement in heart or overall cardiorespiratory function than in skeletal muscle measures, suggesting that some organs may be easier to rescue than others with current approaches. These results are important as research progress but cannot predict how well a similar approach would work in people. [6] [7]

In a knock-in mouse model carrying a Pompe disease variant, neonatal AAV-based gene therapy increased the missing enzyme activity in heart and liver and greatly reduced glycogen buildup in the heart. Heart imaging showed the thickened heart muscle improved toward normal, while skeletal muscle results were more modest, with no clear change in forelimb grip strength and only limited improvement in gait measures. The researchers described this model as a platform for testing next-generation genetic strategies that better target both heart and skeletal muscle. [6]

A separate neonatal rat study also reported that systemic gene therapy restored cardiorespiratory function in a Pompe disease model. The summary did not provide details about specific organs or the size of the effect, but it adds to the general pattern that early gene delivery can improve heart and breathing-related function in animals. [7]

For patients and caregivers, these gene therapy studies mainly matter as early-stage research showing what might be biologically possible, especially for heart involvement. They strengthen the idea that getting the missing enzyme gene into the body early can reverse some heart changes in animals, while highlighting that improving skeletal muscle remains a harder challenge. What is still unknown is how these results translate to safety, durability, and meaningful daily-life benefits in humans, since these experiments were done in newborn animals. [6]