Pompe disease (or Glycogen-storage disease type II) is a metabolic myopathy characterised by a deficiency of acid maltase or acid alpha-glucosidase, an enzyme that is necessary in glycogen degradation. The late-onset form of the disease (late-onset Pompe Disease or LOPD), although it has a better prognosis than the infant-onset form, can lead to highly incapacitating muscle deficiency and respiratory involvement. An enzyme replacement therapy (ERT) has been available for 15 years and has proved beneficial, especially in the infant-onset form, where the effect can be spectacular. However, its benefit in the late-onset form is still controversial.
Indeed, in an article published in April 2021, Swiss clinicians performed a meta-analysis of literature data regarding the clinical efficacy of ERT in LOPD. Sixteen studies or articles were selected from 619 that were initially chosen, corresponding in all to 589 patients. By compiling these patient results, the authors concluded that the benefit with respect to walking is real and statistically significant. Observed over an equal period, they estimate that the distance gained in terms of ability to walk is 32 metres. In contrast, the effect on respiratory function is modest and not statistically significant, and no change is observed in terms of muscle strength per se.