Without treatment the infantile form (which can typically be predicted by mutation analysis) of the disease is particularly lethal - in these cases time to get on treatment is critical, with evidence that days (not weeks or months) matter.Myozyme (alglucosidase alfa) is a recombinant form of the human enzyme acid alpha-glucosidase, and is also currently being used to replace the missing enzyme. In a study which included the largest cohort of patients with Pompe disease treated with enzyme replacement therapy (ERT) to date findings showed that Myozyme treatment clearly prolongs ventilator-free survival and overall survival in patients with infantile-onset Pompe disease as compared to an untreated historical control population. Furthermore, the study demonstrated that initiation of ERT prior to 6 months of age, which could be facilitated by newborn screening, shows great promise to reduce the mortality and disability associated with this devastating disorder. Taiwan and several states in the United States have started the newborn screening and results of such regimen in early diagnosis and early initiation of the therapy have dramatically improved the outcome of the disease; many of these babies have reached the normal motor developmental milestones.Another factor affecting the treatment response is generation of antibodies against the infused enzyme, which is particularly severe in Pompe infants who have complete deficiency of the acid alpha-glucosidase. Immune tolerance therapy to eliminate these antibodies has improved the treatment outcome.A Late Onset Treatment Study (LOTS) was published in 2010.
On June 14, 2007, the Canadian Common Drug Review issued their recommendations regarding public funding for Myozyme therapy. Their recommendation was to provide funding to treat a tiny subset of Pompe patients (Infants less one year of age with cardiomyopathy).On May 26, 2010, FDA approved Lumizyme, a similar version of Myozyme, for the treatment of late-onset Pompe disease. Lumizyme and Myozyme have the same generic ingredient (alglucosidase alfa) and manufacturer (Genzyme Corporation). The difference between these two products is in the manufacturing process. Myozyme is made using a 160-L bioreactor, while Lumizyme uses a 4000-L bioreactor. Because of the difference in the manufacturing process, the FDA claims that the two products are biologically different. Moreover, Lumizyme is FDA approved as replacement therapy for late-onset (noninfantile) Pompe disease without evidence of cardiac hypertrophy in people 8 years and older. Myozyme is FDA approved for replacement therapy for infantile-onset Pompe disease.In July 2021, the European Medicines Agency (EMA) recommended the authorization of avalglucosidase alfa. Avalglucosidase alfa (Nexviazyme) was approved for medical use in the United States in August 2021. Prognosis
The prognosis for individuals with Pompe disease varies according to the onset and severity of symptoms, along with lifestyle factors.