A Milligan

Clinical prodromes of neurodegeneration in Anderson-Fabry disease

Objective: To estimate the prevalence of prodromal clinical features of neurodegeneration in patients with Anderson-Fabry disease (AFD) in comparison to age-matched controls. Methods: This is a single-center, prospective, cross-sectional study in 167 participants (60 heterozygous females and 50 hemizygous males with genetically confirmed AFD, 57 age-matched controls) using a clinical screening program consisting of structured interview, quantitative tests of motor function, and assessments of cognition, depression, olfaction, orthostatic intolerance, pain, REM sleep behavior disorder, and daytime sleepiness. Results: In comparison to age-matched controls (mean age 48.3 years), patients with AFD (mean age 49.0 years) showed slower gait and transfer speed, poorer fine manual dexterity, and lower hand speed, which was independent of focal symptoms due to cerebrovascular disease. Patients with AFD were more severely affected by depression, pain, and daytime sleepiness and had a lower quality of life. These motor and nonmotor manifestations significantly correlated with clinical disease severity. However, patients with AFD did not reveal extrapyramidal motor features or signs of significant cognitive impairment, hyposmia, orthostatic intolerance, or REM sleep behavior disorder, which commonly precede later neurodegenerative disease. In our cohort, there were no differences in neurologic manifestations of AFD between heterozygous females and hemizygous males. Conclusions: Aside from cerebrovascular manifestations and small fiber neuropathy, AFD results in a distinct neurologic phenotype comprising poorer motor performance and specific nonmotor features. In contrast to functional loss of glucocerebrosidase in Gaucher disease, α-galactosidase deficiency in AFD is not associated with a typical cluster of clinical features prodromal for neurodegenerative diseases, such as Parkinson disease.

A randomised, double-blind, placebo-controlled, crossover study to assess the efficacy and safety of three dosing schedules of agalsidase alfa enzyme replacement therapy for Fabry disease

Anecdotal reports suggest that the currently approved dosing interval of agalsidase alfa (0.2 mg/kg/2 weeks) for Fabry disease treatment is too long. This randomised, double-blind, placebo-controlled, crossover study investigated three altered dosing intervals. 18 Fabry patients received three agalsidase alfa dosing schedules, each for four weeks (A: 0.2 mg/kg∗2 weeks, B: 0.1 mg/kg/week, C: 0.2 mg/kg/week). Health state, pain levels, sweat volume and latency and plasma and urinary globotriaosylceramide levels were recorded throughout the study. No significant differences were found among the schedules for the primary efficacy outcome of self-assessed health state, or for pain scores. A trend toward increased sweat volume on QSART testing, and reduced urine globotriaosylceramide concentration were seen with treatment schedule C. Agalsidase alfa was safe and well tolerated with all schedules. In conclusion, the primary analyses did not find weekly infusions of agalsidase alfa to be statistically better than the approved dosing schedule however the data indicates that further studies with more patients over a longer period are required to more accurately determine the optimum dose and schedule.