Treatment-related benefit and satisfaction in patients with Fabry disease in France: insight into patients’ expectations and preferences from the prospective, non-interventional SATIS-Fab study

BACKGROUND: Fabry disease (FD) is a progressive X-linked lysosomal disorder caused by GLA variants resulting in deficient α-galactosidase A enzyme activity, glycolipid accumulation, and multisystemic dysfunction. Approved treatments include intravenous enzyme replacement therapy (ERT) or the oral small-molecule chaperone migalastat. METHODS: SATIS-Fab was a 2-year, prospective, longitudinal, multicentre, non-interventional, non-comparative study conducted in France. Enrolled patients were aged ≥ 16 years, had FD (migalastat-amenable variant), and were receiving/planned to initiate ERT or migalastat. The primary endpoint during follow-up (6-monthly assessments) was the FD-specific Patient Benefit Index (PBI), derived from the French-validated Patient Needs Questionnaire-Fabry and corresponding Patient Benefit Questionnaire. Secondary endpoints included the Treatment Satisfaction Questionnaire for Medication-9 (TSQM-9). RESULTS: Of 69 enrolled patients (mean age 51.7 years; 63.8% male; 60.9% late-onset phenotype), 39/69 were already receiving migalastat and 17/69 ERT. At the baseline visit, 82.6% (57/69) were prescribed migalastat and 17.4% (12/69) ERT. Twelve-month PBI remained stable (mean [SD] 2.36 [0.91] and 2.49 [0.94] at months 12 [n = 55] and 24 [n = 47], respectively; P = 0.173). Mean (SD) 24-month PBI was 2.43 (0.92), and 92.3% of patients (48/52) had a clinically relevant treatment benefit (24-month PBI ≥ 1). Correlations between 24-month PBI and TSQM-9 effectiveness, convenience, and global satisfaction domain scores were 0.63, 0.43, and 0.61, respectively (all P < 0.0001; post hoc analysis); these results confirm the external validity of the PBI. Ten patients switched from ERT to migalastat at/after the baseline visit and before month 24; none switched from migalastat to ERT. For those with available data (n = 8), mean (SD) 12-month PBI increased by 1.14 (0.96) after switching (P = 0.008) and TSQM-9 domain scores improved (all P < 0.05). CONCLUSIONS: Patients with FD, mostly receiving migalastat, reported a relatively high level of treatment benefit that remained stable over 2 years. Switching from ERT to migalastat was associated with significantly increased treatment benefit. The FD-specific PBI could support shared decision making about treatment. TRIAL REGISTRATION: NCT04043273 (registered 31 July 2019).