Safety analysis of self-administered enzyme replacement therapy using data from the Fabry Outcome and Gaucher Outcome Surveys.

Background: Fabry disease and Gaucher disease are rare genetic disorders characterized by defective degradation of glycosphingolipids caused by enzymatic deficiencies in α-galactosidase A and β-glucocerebrosidase, respectively, and often require life-long treatment. Treatment options for these disorders include replacing the deficient enzymes via enzyme replacement therapy (ERT). Agalsidase alfa for Fabry disease and velaglucerase alfa for Gaucher disease are two ERT options with demonstrated efficacy, safety, and tolerability. ERT infusions administered by a health care provider (HCP) in the clinic/hospital, or at the patient's home are considered HCP-supported infusions. Self-administration of ERT (by patient, partner, relative, or caregiver) is optional in patients who tolerate the HCP-supported infusions at home and have a suitable home environment. This analysis explored the safety profiles of self-administered agalsidase alfa (202 patients) and velaglucerase alfa (30 patients) versus HCP-supported infusions using data from the Fabry Outcome Survey (FOS) and Gaucher Outcome Survey (GOS) registries.

Results: The frequency of infusion-related reactions (IRRs) adverse events (AEs) recorded in the two registries was lower in patients self-administering (FOS: 4.5%, GOS: 0%) versus patients receiving HCP-supported infusions (FOS: 13.6%, GOS: 1.6%). In the FOS registry, AE rates per 100 patient-years (100PY) of follow-up were similar between the self-administration (7.99) and HCP-supported infusion (6.78) groups. In patients self-administering agalsidase alfa, cardiac disorders were the most frequently reported AEs (19 [9.4%] patients) and serious AEs (12 [5.9%]) and gastrointestinal disorders were the most frequently reported IRRs (3 [1.5%]). In the GOS registry, AE rates per 100PY were similar between self-administration (4.97) and HCP-supported infusion (4.67) groups. In patients self-administering velaglucerase alfa, skin and subcutaneous disorders (4 [13.3%]) and infections and infestations (2 [6.7%]) were the most reported AEs and serious AEs, respectively, and no IRRs were reported.

Conclusions: These findings suggest that self-administration of agalsidase alfa or velaglucerase alfa infusions are not associated with additional safety risks compared with HCP-supported infusions and are a suitable option for qualifying patients. Further research is warranted to support these findings and to explore further the long-term safety and efficacy of ERT self-administration. FOS trial registration: ClinicalTrials.gov, NCT03289065. Registered 01 April 2001, https://clinicaltrials.gov/study/NCT03289065 . GOS trial registration: ClinicalTrials.gov, NCT03291223. Registered 27 July 2010, https://classic.

Clinicaltrials: gov/ct2/show/NCT03291223 .