Head-to-head trial of pegunigalsidase alfa versus agalsidase beta in patients with Fabry disease and deteriorating renal function: results from the 2-year randomised phase III BALANCE study.

BACKGROUND: Pegunigalsidase alfa is a PEGylated α-galactosidase A enzyme replacement therapy. BALANCE (NCT02795676) assessed non-inferiority of pegunigalsidase alfa versus agalsidase beta in adults with Fabry disease with an annualised estimated glomerular filtration rate (eGFR) slope more negative than -2 mL/min/1.73 m2/year who had received agalsidase beta for ≥1 year. METHODS: Patients were randomly assigned 2:1 to receive 1 mg/kg pegunigalsidase alfa or agalsidase beta every 2 weeks for 2 years. The primary efficacy analysis assessed non-inferiority based on median annualised eGFR slope differences between treatment arms. RESULTS: Seventy-seven patients received either pegunigalsidase alfa (n=52) or agalsidase beta (n=25). At baseline, mean (range) age was 44 (18-60) years, 47 (61%) patients were male, median eGFR was 74.5 mL/min/1.73 m2 and median (range) eGFR slope was -7.3 (-30.5, 6.3) mL/min/1.73 m2/year. At 2 years, the difference between median eGFR slopes was -0.36 mL/min/1.73 m2/year, meeting the prespecified non-inferiority margin. Minimal changes were observed in lyso-Gb3 concentrations in both treatment arms at 2 years. Proportions of patients experiencing treatment-related adverse events and mild or moderate infusion-related reactions were similar in both groups, yet exposure-adjusted rates were 3.6-fold and 7.8-fold higher, respectively, with agalsidase beta than pegunigalsidase alfa. At the end of the study, neutralising antibodies were detected in 7 out of 47 (15%) pegunigalsidase alfa-treated patients and 6 out of 23 (26%) agalsidase beta-treated patients. There were no deaths. CONCLUSIONS: Based on rate of eGFR decline over 2 years, pegunigalsidase alfa was non-inferior to agalsidase beta. Pegunigalsidase alfa had lower rates of treatment-emergent adverse events and mild or moderate infusion-related reactions. TRIAL REGISTRATION NUMBER: NCT02795676.

Impact of Infliximab-dyyb (Infliximab Biosimilar) on Clinical and Patient-Reported Outcomes: 1-Year Follow-up Results from an Observational Real-World Study Among Patients with Inflammatory Bowel Disease in the US and Canada (the ONWARD Study).

INTRODUCTION: To date, there are limited real-world studies published on the use of infliximab-dyyb, a biosimilar to reference product (RP) infliximab approved for the treatment of moderate to severe inflammatory bowel disease (IBD), including Crohn's disease (CD) and ulcerative colitis (UC) in North America. This study examined utilization patterns and the effects of infliximab-dyyb on clinical outcomes, patient-reported outcomes (PROs), and healthcare resource use (HCRU) in IBD patients in a real-world setting. METHODS: In this prospective, observational study, adult IBD patients in the US and Canada were recruited to initiate treatment with infliximab-dyyb and followed for 12 months. Patients included biologic-naïve users of infliximab-dyyb and patients switching from RP infliximab or other biologics to infliximab-dyyb. Partial Mayo (pMAYO) and Harvey Bradshaw Index (HBI) scores measured clinical outcomes for the UC and CD cohorts, respectively. Key PRO measures included the SIBDQ, EQ-VAS, and psychological outcomes. In addition, work productivity, HCRU, and adverse events (AEs) were assessed. RESULTS: A total of 67 CD and 48 UC patients were enrolled (51% female; mean age 44 years; 87% Caucasian; mean BMI 27.9). Thirty-nine patients were biologic-naïve, 57 switched from RP infliximab, and 19 switched from other biologics. Among UC biologic-naïve users, pMAYO decreased from 5.67 to 1.09 (p < 0.0001) and the remission rate increased from 5.6 to 90.9% (p = 0.0015). For UC patients switching from RP infliximab, pMAYO decreased from 1.38 to 0.29 (p = 0.0103). For CD biologic-naïve users, HBI scores and remission rates did not significantly change. The scores on all the PROs significantly improved from baseline to 12 months. A total of 22 AEs occurred consistent with the known AE profile for infliximab. CONCLUSIONS: Clinical outcomes among biologic-naïve users of infliximab-dyyb improved for UC and were maintained for CD patients. Biologic-naïve users of infliximab-dyyb showed significant improvements in PROs. Patients switching from RP infliximab to infliximab-dyyb maintained their clinical outcomes and PROs. TRIAL REGISTRATION: ClinicalTrials.gov Registration Number: NCT03801928 (February 23, 2018).

Long-term efficacy and safety of migalastat treatment in Fabry disease: 30-month results from the open-label extension of the randomized, phase 3 ATTRACT study.

Results from the 18-month randomized treatment period of the phase 3 ATTRACT study demonstrated the efficacy and safety of oral migalastat compared with enzyme replacement therapy (ERT) in patients with Fabry disease who previously received ERT. Here, we report data from the subsequent 12-month, migalastat-only, open-label extension (OLE) period. ATTRACT (Study AT1001-012; NCT01218659) was a randomized, open-label, active-controlled study in patients aged 16-74 years with Fabry disease, an amenable GLA variant, and an estimated glomerular filtration rate (eGFR) ≥30 mL/min/1.73 m2. During the OLE, patients who received migalastat 150 mg every other day (QOD) during the randomized period continued receiving migalastat (Group 1 [MM]); patients who received ERT every other week discontinued ERT and started migalastat treatment (Group 2 [EM]). Outcome measures included eGFR, left ventricular mass index (LVMi), composite clinical outcome (renal, cardiac or cerebrovascular events), and safety. Forty-six patients who completed the randomized treatment period continued into the OLE (Group 1 [MM], n = 31; Group 2 [EM], n = 15). eGFR remained stable in both treatment groups. LVMi decreased from baseline at month 30 in Group 1 (MM) in patients with left ventricular hypertrophy at baseline. Only 10% of patients experienced a new composite clinical event with migalastat treatment during the OLE. No new safety concerns were reported. In conclusion, in patients with Fabry disease and amenable GLA variants, migalastat 150 mg QOD was well tolerated and demonstrated durable, long-term stability of renal function and reduction in LVMi.

Altered immune phenotypes in subjects with Fabry disease and responses to switching from agalsidase alfa to agalsidase beta.

Fabry disease (FD) is a rare X-linked genetic disorder caused by mutations in the GLA gene encoding the lysosomal enzyme, α-galactosidase A (α-gal A). The mutations lead to lack of or faulty enzyme causing accumulation of globotriaosylceramide (Gb3) and related glycosphingolipids including globotriaosylsphingosine (lyso-Gb3). Treatment options for FD include enzyme replacement therapy. There are two different recombinant α-gal A enzymes, where agalsidase beta has been approved by FDA for use in the USA while both agalsidase beta and agalsidase alfa are being prescribed in many other countries. Several FD patients in the USA were switched to agalsidase alfa for a certain period of time due to supply shortage of agalsidase beta but were switched back to agalsidase beta upon availability. Due to the fact that some glycolipids may serve as antigens, various immune abnormalities have been associated with several lysosomal storage disorders (LSDs). In the present clinical study we evaluated alterations in peripheral immune cell subsets in patients with FD (n=27) compared to healthy control group (n=27). Patients with FD showed persistent T cell associated abnormalities, including skewed T helper to cytotoxic T cell ratio and elevated fraction of memory T cells and expression of activation markers on T cell subsets. Further, the study elucidated the effect of switching from agalsidase alfa to agalsidase beta on immune system as well as other clinical markers. While there was relative decrease in plasma lyso-Gb3 as well as urine lyso-Gb3 over time, their levels remained above the reference values. The immune abnormalities did not correlate with gender, age or lyso-Gb3 levels, indicating that these persistent changes were inherent to FD irrespective of the extent of substrate accumulation.

Oral pharmacological chaperone migalastat compared with enzyme replacement therapy in Fabry disease: 18-month results from the randomised phase III ATTRACT study.

BACKGROUND: Fabry disease is an X-linked lysosomal storage disorder caused by GLA mutations, resulting in α-galactosidase (α-Gal) deficiency and accumulation of lysosomal substrates. Migalastat, an oral pharmacological chaperone being developed as an alternative to intravenous enzyme replacement therapy (ERT), stabilises specific mutant (amenable) forms of α-Gal to facilitate normal lysosomal trafficking. METHODS: The main objective of the 18-month, randomised, active-controlled ATTRACT study was to assess the effects of migalastat on renal function in patients with Fabry disease previously treated with ERT. Effects on heart, disease substrate, patient-reported outcomes (PROs) and safety were also assessed. RESULTS: Fifty-seven adults (56% female) receiving ERT (88% had multiorgan disease) were randomised (1.5:1), based on a preliminary cell-based assay of responsiveness to migalastat, to receive 18 months open-label migalastat or remain on ERT. Four patients had non-amenable mutant forms of α-Gal based on the validated cell-based assay conducted after treatment initiation and were excluded from primary efficacy analyses only. Migalastat and ERT had similar effects on renal function. Left ventricular mass index decreased significantly with migalastat treatment (-6.6 g/m2 (-11.0 to -2.2)); there was no significant change with ERT. Predefined renal, cardiac or cerebrovascular events occurred in 29% and 44% of patients in the migalastat and ERT groups, respectively. Plasma globotriaosylsphingosine remained low and stable following the switch from ERT to migalastat. PROs were comparable between groups. Migalastat was generally safe and well tolerated. CONCLUSIONS: Migalastat offers promise as a first-in-class oral monotherapy alternative treatment to intravenous ERT for patients with Fabry disease and amenable mutations. TRIAL REGISTRATION NUMBER: NCT00925301; Pre-results.

Treatment of Fabry's Disease with the Pharmacologic Chaperone Migalastat.

BACKGROUND: Fabry's disease, an X-linked disorder of lysosomal α-galactosidase deficiency, leads to substrate accumulation in multiple organs. Migalastat, an oral pharmacologic chaperone, stabilizes specific mutant forms of α-galactosidase, increasing enzyme trafficking to lysosomes. METHODS: The initial assay of mutant α-galactosidase forms that we used to categorize 67 patients with Fabry's disease for randomization to 6 months of double-blind migalastat or placebo (stage 1), followed by open-label migalastat from 6 to 12 months (stage 2) plus an additional year, had certain limitations. Before unblinding, a new, validated assay showed that 50 of the 67 participants had mutant α-galactosidase forms suitable for targeting by migalastat. The primary end point was the percentage of patients who had a response (≥50% reduction in the number of globotriaosylceramide inclusions per kidney interstitial capillary) at 6 months. We assessed safety along with disease substrates and renal, cardiovascular, and patient-reported outcomes. RESULTS: The primary end-point analysis, involving patients with mutant α-galactosidase forms that were suitable or not suitable for migalastat therapy, did not show a significant treatment effect: 13 of 32 patients (41%) who received migalastat and 9 of 32 patients (28%) who received placebo had a response at 6 months (P=0.30). Among patients with suitable mutant α-galactosidase who received migalastat for up to 24 months, the annualized changes from baseline in the estimated glomerular filtration rate (GFR) and measured GFR were -0.30±0.66 and -1.51±1.33 ml per minute per 1.73 m(2) of body-surface area, respectively. The left-ventricular-mass index decreased significantly from baseline (-7.7 g per square meter; 95% confidence interval [CI], -15.4 to -0.01), particularly when left ventricular hypertrophy was present (-18.6 g per square meter; 95% CI, -38.2 to 1.0). The severity of diarrhea, reflux, and indigestion decreased. CONCLUSIONS: Among all randomly assigned patients (with mutant α-galactosidase forms that were suitable or not suitable for migalastat therapy), the percentage of patients who had a response at 6 months did not differ significantly between the migalastat group and the placebo group. (Funded by Amicus Therapeutics; ClinicalTrials.gov numbers, NCT00925301 [study AT1001-011] and NCT01458119 [study AT1001-041].).

Reduction of Plasma Globotriaosylsphingosine Levels After Switching from Agalsidase Alfa to Agalsidase Beta as Enzyme Replacement Therapy for Fabry Disease.

INTRODUCTION: Agalsidase alfa and agalsidase beta, recombinant enzyme preparations for treatment of Fabry disease (FD), have different approved dosing schedules: 0.2 mg/kg and 1.0 mg/kg every other week (EOW), respectively. METHODS: This open-label, multicenter, exploratory phase 4 study evaluated plasma globotriaosylsphingosine (lyso-GL-3) and plasma and urine globotriaosylceramide (GL-3) levels at baseline and 2, 4, and 6 months after the switch from agalsidase alfa (0.2 mg/kg EOW for ≥12 months) to agalsidase beta (1.0 mg/kg EOW) in 15 male patients with FD. Immunoglobulin (Ig)G antidrug antibody titers were assessed, and safety was monitored throughout the study. RESULTS: Plasma lyso-GL-3 concentrations decreased significantly within 2 months after switch and reductions continued through month 6 (mean absolute changes, -12.8, -16.1, and -16.7 ng/mL at 2, 4, and 6 months, respectively; all P < 0.001). The mean percentage reduction from baseline was 39.5% (P < 0.001) at month 6. For plasma GL-3, the mean absolute change from baseline (-0.9 µg/mL) and percentage reduction (17.9%) at month 6 were both significant (P < 0.05). Urine GL-3 measurements showed intra-patient variability and changes from baseline were not significant. No clinical outcomes were assessed in this 6-month study, and, therefore, no conclusions can be drawn regarding the correlation of observed reductions in glycosphingolipid concentrations with clinically relevant outcomes. There were no differences in IgG antidrug antibody titers between the two enzymes. The switch from agalsidase alfa to agalsidase beta was well tolerated. CONCLUSION: Plasma lyso-GL-3 and GL-3 levels reduced after switching from agalsidase alfa to agalsidase beta, indicating that agalsidase beta has a greater pharmacodynamic effect on these markers at the recommended dose. These data further support the use of agalsidase beta 1.0 mg/kg EOW as enzyme replacement therapy in FD.

Effect and Tolerability of Agalsidase Alfa in Patients with Fabry Disease Who Were Treatment Naïve or Formerly Treated with Agalsidase Beta or Agalsidase Alfa.

OBJECTIVES: In a multicenter, open-label, treatment protocol (HGT-REP-059; NCT01031173), clinical effects and tolerability of agalsidase alfa (agalα; 0.2 mg/kg every other week) were evaluated in patients with Fabry disease who were treatment naïve or switched from agalsidase beta (switch). Over 24 months, data were collected on the safety profile; renal and cardiac parameters were assessed using estimated glomerular filtration rate (eGFR), left ventricular mass index (LVMI), and midwall fractional shortening (MFS). RESULTS: Enrolled patients included 71 switch (median [range] age, 46.6 [5-84] years; male to female [M:F], 40:31) and 29 treatment naïve (38.7 [12-74] years; M:F, 14:15). Adverse events (AEs) were consistent with the known safety profile of agalα. Two switch patients had hospitalization due to possibly/probably drug-related serious AEs (one with transient ischemic attack, one with infusion-related AEs). One switch and two treatment-naïve patients discontinued treatment because of AEs. Three patients (one each switch, treatment naïve, and previous agalα) died; no deaths were considered drug-related. There was no significant change from baseline in LVMI or MFS in either group. Similarly, eGFR remained stable; mean ± standard error annualized change in eGFR (mL/min/1.73 m(2)) was -2.40 ± 1.04 in switch and -1.68 ± 2.21 in treatment-naïve patients. CONCLUSIONS: This is the largest cohort of patients with Fabry disease who were started on or switched to agalα in an FDA-accepted protocol during a worldwide supply shortage of agalsidase beta. Because this protocol was primarily designed to provide access to agalα, there were limitations, including not having stringent selection criteria and the lack of a placebo group.

Safety and efficacy of alternative alglucosidase alfa regimens in Pompe disease.

Emerging phenotypes in long-term survivors with Pompe disease on standard enzyme replacement therapy (ERT) (alglucosidase alfa 20 mg/kg/2 weeks) can include patients with worsening motor function. Whether higher doses of ERT improve skeletal function in these patients has not been systematically studied. This exploratory, randomized, open-label, 52-week study examined the safety and efficacy of 2 ERT regimens of alglucosidase alfa (20 mg/kg/week or 40 mg/kg/2 weeks) in 13 patients with Pompe disease and clinical decline or a lack of improvement on standard ERT: late-onset (n = 4), infantile-onset (n = 9). Cross-reactive immunologic material assay-negative patients were excluded. Eleven of 13 patients completed the study. Trends for improvement were seen in total gross motor function, but not mobility; however, 6 (late-onset, 2; infantile-onset, 4) of 11 patients (55%) who met the entry criteria of motor decline (late-onset, 4; infantile-onset, 7) showed improvement in motor and/or mobility skills. No between-regimen differences in efficacy emerged. Two case studies highlight the benefits of increased ERT dose in patients with Pompe disease experiencing clinical decline. Both alternative regimens were generally well tolerated. This study was limited by the small sample size, which is not uncommon for small clinical studies of rare diseases. Additionally, the study did not include direct assessment of muscle pathology, which may have identified potential causes of decreased response to ERT. Results were inconclusive but suggest that increased ERT dose may be beneficial in some patients with Pompe disease experiencing motor decline. Controlled studies are needed to clarify the benefits and risks of this strategy.