Open Label Extension Study of 1 mg/kg Pegunigalsidase Alfa Every 2 Weeks in Patients With Fabry Disease

No primary or secondary endpoints were specified for this trial. Evaluation of safety was a main objective.

A treatment-emergent adverse event (TEAE) was defined as any adverse event (AE) occurring after the start of study treatment and within the time of residual drug effect (20 days after last administration of study treatment) or a pre-treatment AE or medical condition that worsened in severity after the start of study treatment and within the time of residual drug effect. Each TEAE was classified for severity based on the Common Terminology Criteria for Adverse Events (CTCAE) v4.03 and for causality in the categories unrelated, unlikely, possible, probable and definitely. Treatment-related AEs were TEAEs with causality assessed as possible, probable or definitely related to study treatment. TEAEs were coded using the Medical Dictionary for Regulatory Activities (MedDRA) version (v)19.0. Related TEAEs reported in ≥2 percent of participants by Preferred Term are reported.

The eGFR, calculated based on serum creatinine values, according to the Chronic Kidney Disease - Epidemiology Collaboration (CKD-EPI) formula (2009).

The annualized eGFR slope was added in the statistical analysis plan. Individual eGFR slopes were derived for each participant using a linear regression model and summarized descriptively.

The UPCR was assessed by spot urine test. Participants were categorized according to UPCR at baseline and subsequent visits.

Plasma concentrations of Lyso-Gb3 and Gb3 (biomarkers for Fabry disease) were assessed at baseline and subsequent time points and change from baseline was assessed.

The short form Brief Pain Inventory (BPI) consists of 4 pain severity items (pain at its worst in the last 24 hours, pain at its least in the last 24 hours, pain on average and current pain) and 7 pain interference items (general activity, mood, walking ability, normal work, relations with other people, sleep and enjoyment of life) assessed over a 24-hour recall period. Each item is rated on a scale from 0 (no pain/interference) to 10 (worst pain imaginable/complete interference). Participants report percentage of pain relief by analgesics over the past 24 hours as well. Assessment of pain (by the BPI) was performed at baseline and subsequent time points.

The MSSI represents patients with Fabry disease. Overall scores of <20, ≥20 and ≤40 and >40 indicate that patients are mildly, moderately or severely affected, respectively. An increase in the score indicates increased severity of the disease. Symptom assessment by the MSSI was performed at baseline and at subsequent time points.

The ranges for the MSSI general, neurological, cardiovascular and renal dysfunction domain scores are 0 to 18, 0 to 20, 0 to 20 and 0 to 18 respectively. The overall score considered for the study is the sum of the domain scores - min 0 max 76

At baseline, participants were categorized by the number of pain medications used (0, 1 and 2+ pain medications). Shifts from baseline to 72 months in the number of participants using pain medications (categorized by number of pain medications used) are presented.

Quality of life was assessed by administering the EuroQoL-5 Dimensions-5 Levels (EQ-5D-5L) questionnaire at baseline and subsequent time points. The assessment includes the EuroQoL-5 Dimensions (EQ-5D) descriptive system and the EQ VAS. For the EQ VAS, participants rated their current health on a vertical VAS which has endpoints labelled 'the best health you can imagine' (score of 100) and 'the worst health you can imagine' (score of 0). An increase in score indicates improvement.

Cardiac assessment was performed by cardiac magnetic resonance imaging (MRI) at baseline and subsequent time points and various parameters including the left ventricular mass index (LVMI) (g/m^2) with and without hypertrophy were assessed.

Infusion premedication use was not collected in studies PB-102-F01/F02/F03. Changes in use of infusion premedication were analyzed in a pooled sample of participants enrolled from studies PB-102-F20 and PB-102-F30. Participants were categorized at baseline by number of infusion premedications used (0, 1, 2 and 3 or more) and shifts from baseline to 12 months in the number of participants using infusion premedications, categorized by number of infusion premedications used, are presented.

Infusion premedication use was not collected in studies PB-102-F01/F02/F03. Changes in use of infusion premedication were analyzed in a pooled sample of participants enrolled from studies PB-102-F20 and PB-102-F30. Participants were categorized at baseline by number of infusion premedications used (0, 1, 2 and 3 or more) and shifts from baseline to 24 months in the number of participants using infusion premedications, categorized by number of infusion premedications used, are presented.

Infusion premedication use was not collected in studies PB-102-F01/F02/F03. Changes in use of infusion premedication were analyzed in a pooled sample of participants enrolled from studies PB-102-F20 and PB-102-F30. Participants were categorized at baseline by number of infusion premedications used (0, 1, 2 and 3 or more) and shifts from baseline to 48 months in the number of participants using infusion premedications, categorized by number of infusion premedications used, are presented.

Infusion premedication use was not collected in studies PB-102-F01/F02/F03. Changes in use of infusion premedication were analyzed in a pooled sample of participants enrolled from studies PB-102-F20 and PB-102-F30. Participants were categorized at baseline by number of infusion premedications used (0, 1, 2 and 3 or more) and shifts from baseline to 72 months in the number of participants using infusion premedications, categorized by number of infusion premedications used, are presented.

The ADA status was assessed as per the schedule of assessments based on sequential evaluation. The participant was considered ADA-positive if IgG screening was presumptive positive and subsequent IgG immunodepletion was positive.

The ADA status at a visit was decided based on a sequential evaluation as per the schedule of assessments. If the IgG screening was negative, the participant was ADA-negative at that visit. If the IgG screening was presumptive positive, an IgG immunodepletion test was performed and the participant was considered ADA-positive or -negative at the visit based on whether the test was positive or negative. Baseline was the last assessment before the first infusion of pegunigalsidase alfa. Participants were considered to be treatment-emergent ADA-positive if they had titer-boosted or treatment-induced ADA. The ADA were titer-boosted if participants were ADA-positive at baseline and ADA titer had increased by at least 4-fold from baseline during treatment. The ADA were treatment-induced if participants were ADA-negative at baseline and ADA-positive in at least one timepoint post-first infusion.

An IRR was defined as a reaction to the infusion of pharmacological and/or biological substances; symptoms could appear within minutes to 2 hours following the end of the infusion and could include pruritus, flushing, swelling, dyspnea, bronchospasm and hypotension. IRRs could be evaluated up to 24 hours from occurrence. Two time frames were considered for IRR analysis: IRR-2H and IRRs occurring during the infusion or within 24 hours after its completion (IRR-24H). All IRR-2H were also classified as IRR-24H. The IRR-2H reported for more than one participant overall by MedDRA PT are presented.

An IRR was defined as a reaction to the infusion of pharmacological and/or biological substances; symptoms could appear within minutes to 2 hours following the end of the infusion and could include pruritus, flushing, swelling, dyspnea, bronchospasm and hypotension. IRRs could be evaluated up to 24 hours from occurrence. Two time frames were considered for IRR analysis: IRR-2H and IRR-24H. All IRR-2H were also classified as IRR-24H. IRR-24H reported for more than one participant overall by MedDRA PT are presented.