An AE was defined as any untoward medical occurrence in a participant administered migalastat that did not necessarily have a causal relationship with the treatment. Each AE was recorded at time of reporting; visits typically occurred every 6 months. Serious AEs were life threatening or resulted in death, resulted in disability/incapacity, hospitalization or prolonged hospitalization, or a congenital anomaly. The criteria for AE severity were: Mild: awareness of sign or symptom, does not interfere with normal everyday activities; Moderate: discomforting, interferes with normal everyday activities, but able to function; Severe: incapacitating, prevents normal everyday activities or significantly affects clinical status and requires medical intervention. A summary of serious and all other non-serious AEs regardless of causality is located in the Reported Adverse Events module.

Safety Population: All participants who received at least 1 dose of study drug after they enrolled into this open-label extension study.

The annualized rate of change in the eGFR was assessed per participant by the slope of the simple linear regression between the observed values and the assessment times. It was calculated by using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equation (eGFR [CKD-EPI]) and the Modification of Diet in Renal Disease (MDRD) equation (eGFR [MDRD]). The equations are as follows:

eGFR [MDRD] = 175 × (1/Serum Creatinine in mg/deciliter^1.154) × (1/Age in years^0.203) × 0.742 [if female] × 1.212 [if black] × 0.808 [if Japanese];

eGFR [CKD-EPI] = 141 × min(Serum creatinine [Scr]/k, 1)α × max(Scr/k, 1) - 1.209 × 0.993Age × 1.018 [if female] × 1.159 [if black],

where Scr is serum creatinine, k is 0.7 for females and 0.9 for males, α is -0.329 for females and -0.411 for males, min indicates the minimum of Scr/k or 1, and max indicates the maximum of Scr/k or 1.

Participants with at least a Baseline and a post-Baseline value are presented.

Intent-to-Treat Population: all participants who took at least 1 dose of the study drug after they had enrolled into this study.

The change from baseline in eGFR was calculated using eGFR[CKD-EPI] and eGFR[MDRD] equations. Baseline was defined as the data collected at Month 0, if not available, it was the last visit of the previous (feeder) study if done within 6 months. End of Study was the last recorded observation for each participant (approximately 30 days after last treatment). Only participants with both a Baseline value and an End of Study value were included in the change from baseline analysis.

All participants who took at least 1 dose of the study drug after they had enrolled into this study and had analyzable data at the specified time points.

Concentrations of lyso-Gb3 were measured in plasma using a qualified assay. Baseline was defined as the data collected at Month 0, if not available, it was the last visit of the previous (feeder) study if done within 6 months. End of study was the last recorded observation for each participant (approximately 30 days after last treatment). Only participants with both a Baseline value and an End of Study value were included in the change from baseline analysis.

All participants who took at least 1 dose of the study drug after they had enrolled into this study and had analyzable data at the specified time points.

The activity of the α-galactosidase A (α-Gal A) enzyme was measured in leukocyte lysate by a validated fluorometric assay method, using 4-methylumbelliferone as a reference. The activity values obtained were normalized to protein (measured using a colorimetric assay). Baseline was defined as the data collected at Month 0, if not available, it was the last visit of the previous (feeder) study if done within 6 months. End of Study was the last recorded observation for each participant (approximately 30 days after last treatment). Results for male participants are reported. Only participants with both a Baseline value and an End of Study value were included in the change from baseline analysis.

All male participants who took at least 1 dose of the study drug after they had enrolled into this study and had analyzable data at the specified time points.

A 24-hour urine sample was collected to measure 24-hour urine protein. Baseline was defined as the data collected at Month 0, if not available, it was the last visit of the previous (feeder) study if done within 6 months. End of Study was the last recorded observation for each participant (approximately 30 days after last treatment). Only participants with both a Baseline value and an End of Study value were included in the change from baseline analysis.

All participants who took at least 1 dose of the study drug after they had enrolled into this study and had analyzable data at the specified time points.

LVM was measured by echocardiography. Baseline was defined as the data collected at Month 0, if not available, it was the last visit of the previous (feeder) study if done within 6 months. End of Study was the last recorded observation for each participant (approximately 30 days after last treatment). Only participants with both a Baseline value and an End of Study value were included in the change from baseline analysis.

All participants who took at least 1 dose of the study drug after they had enrolled into this study and had analyzable data at the specified time points.

LVMi was measured by echocardiography. Baseline was defined as the data collected at Month 0, if not available, it was the last visit of the previous (feeder) study if done within 6 months. End of Study was the last recorded observation for each participant (approximately 30 days after last treatment). Only participants with both a Baseline value and an End of Study value were included in the change from baseline analysis.

All participants who took at least 1 dose of the study drug after they had enrolled into this study and had analyzable data at the specified time points.

The SF-36 is a participant self-rated questionnaire that is a general measure of perceived health status comprising 36 questions, which yields an 8-scale health profile (Physical Functioning, Role Physical, Bodily Pain, General Health, Vitality, Social Functioning, Role Emotional, and Mental Health). Scores on each item are summed and averaged (range: 0=worst to 100=best). Scores were normed to the US population. Higher score indicates less disability. A positive change from baseline indicates improvement. Baseline was defined as the data collected in the last visit of the previous (feeder) study. Only participants with both a Baseline value and an End of Study value were included in the change from baseline analysis.

All participants who took at least 1 dose of the study drug after they had enrolled into this study and had analyzable data at the specified time points.