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.

Long-term safety and efficacy of pegunigalsidase alfa: A multicenter 6-year study in adult patients with Fabry disease.

PURPOSE: Fabry disease (FD) is a rare lysosomal storage disorder caused by pathogenic variants in the GLA gene encoding α-galactosidase (α-Gal)-A. We evaluated long-term safety/efficacy of pegunigalsidase alfa, a novel PEGylated α-Gal-A enzyme replacement therapy (ERT) now approved for FD. METHODS: In a phase-1/2 dose-ranging study, 15 ERT-naive adults with FD completed 12 months of pegunigalsidase alfa and enrolled in this 60-month open-label extension of 1 mg/kg pegunigalsidase alfa infusions every 2 weeks. RESULTS: Fifteen patients enrolled (8 males; 7 females); 10 completed ≥48 months (60 months total treatment), and 2 completed 60 months (72 months total treatment). During treatment, most treatment-emergent adverse events were mild/moderate in severity and all infusion-related reactions were mild/moderate in severity. Four patients were transiently positive for anti-pegunigalsidase alfa IgG. Patients showed continuous reduction in plasma lyso-Gb3 concentrations with mean (standard error) reduction of 76.1 [25.1] ng/mL from baseline to month 24. At 60 months, the estimated glomerular filtration rate slope was comparable to that observed in patients treated with other ERTs. Cardiac function assessments revealed stability; no cardiac fibrosis was observed. CONCLUSION: In this first long-term assessment of pegunigalsidase alfa administration in patients with FD, we found favorable safety/efficacy. Our data suggest long-term continuous benefits of pegunigalsidase alfa treatment in adults with FD.

A novel unbiased method reveals progressive podocyte globotriaosylceramide accumulation and loss with age in females with Fabry disease.

While females can suffer serious complications of Fabry disease, most studies are limited to males to avoid confounding by mosaicism. Here, we developed a novel unbiased method for quantifying globotriaosylceramide (GL3) inclusion volume in affected podocytes (F+) in females with Fabry disease independent of mosaicism leading to important new observations. All podocytes in male patients with Fabry are F+. The probability of observing random profiles from F+ podocytes without GL3 inclusions (estimation error) was modeled from electron microscopic studies of 99 glomeruli from 40 treatment-naïve males and this model was applied to 28 treatment-naïve females. Also, podocyte structural parameters were compared in 16 age-matched treatment-naïve males and females with classic Fabry disease and 11 normal individuals. A 4th degree polynomial equation best described the relationship between podocyte GL3 volume density and the estimation error (R2 =0.94) and was confirmed by k-fold cross-validation. In females, this model showed that age related directly to F+ podocyte GL3 volume (correlation coefficient (r = 0.54) and podocyte volume (r = 0.48) and inversely to podocyte number density (r = -0.56), (all significant). F+ podocyte GL3 volume was significantly inversely related to podocyte number density (r = -0.79) and directly to proteinuria. There was no difference in F+ podocyte GL3 volume or volume fraction between age-matched males and females. Thus, in females with Fabry disease GL3 accumulation in F+ podocytes progresses with age in association with podocyte loss and proteinuria, and F+ podocyte GL3 accumulation in females with Fabry is similar to males, consistent with insignificant cross-correction between affected and non-affected podocytes. Hence, these findings have important pathophysiological and clinical implications.

Exponential increase in neutralizing and spike specific antibodies following vaccination of COVID-19 convalescent plasma donors.

BACKGROUND: With the recent approval of COVID-19 vaccines, recovered COVID-19 subjects who are vaccinated may be ideal candidates to donate COVID-19 convalescent plasma (CCP). CASE SERIES: Eleven recovered COVID-19 patients were screened to donate CCP. All had molecularly confirmed COVID-19, and all but one were antibody positive by chemiluminescence immunoassay (DiaSorin) prior to vaccination. All were tested again for antibodies 11-21 days after they were vaccinated (Pfizer/Moderna). All showed dramatic increases (~50-fold) in spike-specific antibody levels and had at least a 20-fold increase in the IC50 neutralizing antibody titer based on plaque reduction neutralization testing (PRNT). The spike-specific antibody levels following vaccination were significantly higher than those seen in any non-vaccinated COVID-19 subjects tested to date at our facility. CONCLUSION: Spike-specific and neutralizing antibodies demonstrated dramatic increases following a single vaccination after COVID-19 infection, which significantly exceeded values seen with COVID-19 infection alone. Recovered COVID-19 subjects who are vaccinated may make ideal candidates for CCP donation.

Initial experience from a renal genetics clinic demonstrates a distinct role in patient management.

PURPOSE: A Renal Genetics Clinic (RGC) was established to optimize diagnostic testing, facilitate genetic counseling, and direct clinical management. METHODS: Retrospective review of patients seen over a two-year period in the RGC. RESULTS: One hundred eleven patients (mean age: 39.9 years) were referred to the RGC: 65 for genetic evaluation, 19 for management of a known genetic disease, and 18 healthy living kidney donors (LKDs) and their 9 related transplant candidates for screening. Forty-three patients underwent genetic testing with a diagnosis in 60% of patients including 9 with Alport syndrome, 7 with autosomal dominant polycystic kidney disease (ADPKD), 2 with genetic focal segmental glomerulosclerosis (FSGS), 2 with PAX2-mediated CAKUT, and 1 each with autosomal recessive polycystic kidney disease (ARPKD), Dent, Frasier, Gordon, Gitelman, and Zellweger syndromes. Four of 18 LKDs were referred only for APOL1 screening. For the remaining 14 LKDs, their transplant candidates were first tested to establish a genetic diagnosis. Five LKDs tested negative for the familial genetic variant, four were positive for their familial variant. In five transplant candidates, a genetic variant could not be identified. CONCLUSION: An RGC that includes genetic counseling enhances care of renal patients by improving diagnosis, directing management, affording presymptomatic family focused genetic counseling, and assisting patients and LKDs to make informed decisions.

Pegunigalsidase alfa, a novel PEGylated enzyme replacement therapy for Fabry disease, provides sustained plasma concentrations and favorable pharmacodynamics: A 1-year Phase 1/2 clinical trial.

Pegunigalsidase alfa, a novel PEGylated, covalently crosslinked form of α-galactosidase A developed as enzyme replacement therapy (ERT) for Fabry disease (FD), was designed to increase plasma half-life and reduce immunogenicity, thereby enhancing efficacy compared with available products. Symptomatic adults with FD participated in this open-label, 3-month dose-ranging study, followed by a 9-month extension. Three cohorts were enrolled in a stepwise manner, each receiving increased doses of pegunigalsidase alfa: 0.2, 1.0, 2.0 mg/kg, via intravenous infusion every other week. Pharmacokinetic analysis occurred on Day 1 and Months 3, 6, and 12. Kidney biopsies at baseline and Month 6 assessed peritubular capillary globotriaosylceramide (Gb3) content. Renal function, cardiac parameters, and other clinical endpoints were assessed throughout. Treatment-emergent adverse events (AEs) and presence of immunoglobulin G (IgG) antidrug antibodies (ADAs) were assessed. Sixteen patients completed 1 year's treatment. Mean terminal plasma half-life (each cohort) ranged from 53 to 121 hours. All 11 male and 1 of 7 female patients presented with classic FD phenotype, in whom renal peritubular capillary Gb3 inclusions were reduced by 84%. Mean estimated glomerular filtration rate was 111 mL/min/1.73 m2 at baseline, remaining stable throughout treatment. Three patients developed treatment-induced IgG ADAs; following 1 year's treatment, all became ADA-negative. Nearly all treatment-emergent AEs were mild or moderate. One patient withdrew from the study following a serious related AE. Pegunigalsidase alfa may represent an advance in ERT for FD, based on its unique pharmacokinetics and apparent low immunogenicity.

The Impact of Fabry Disease on Reproductive Fitness.

Fabry disease (FD) is a pan-ethnic, X-linked, progressive lysosomal storage disorder caused by pathogenic mutations in the GLA gene. Published case reports and abstracts suggest that decreased reproductive fitness may occur in males with FD. In order to understand the impact of FD on reproductive fitness and increase the accuracy of reproductive genetic counseling, this study examines a large, multi-centered population of individuals with FD to determine if males have reduced reproductive fitness. Study data were collected on 376 patients through two, gender-specific surveys distributed across the United States and Canada. The number of biological live-born children among individuals with FD was compared to statistics from the general population. Information was also collected on reduced sperm count, depression, pain, use of assisted reproductive technology, and reproductive choice. On average, females affected by FD had more biological live-born children (1.8) than males affected by FD (1.1). However, males affected by FD had an increased mean number of biological children (1.1) compared to the mean number of biological children fathered by men in the United States (0.9). Sixteen of the 134 males with FD reported oligospermia, which suggests that an infertility work up may be indicated for males having difficulty impregnating their partners. In our large multicenter sample, males and females with FD do not exhibit reduced reproductive fitness; on average they have more biological children than the general population in the United States. This information should assist clinicians in providing accurate reproductive genetic counseling and treatment for individuals with FD.

Oral Migalastat HCl Leads to Greater Systemic Exposure and Tissue Levels of Active α-Galactosidase A in Fabry Patients when Co-Administered with Infused Agalsidase.

UNLABELLED: Migalastat HCl (AT1001, 1-Deoxygalactonojirimycin) is an investigational pharmacological chaperone for the treatment of α-galactosidase A (α-Gal A) deficiency, which leads to Fabry disease, an X-linked, lysosomal storage disorder. The currently approved, biologics-based therapy for Fabry disease is enzyme replacement therapy (ERT) with either agalsidase alfa (Replagal) or agalsidase beta (Fabrazyme). Based on preclinical data, migalastat HCl in combination with agalsidase is expected to result in the pharmacokinetic (PK) enhancement of agalsidase in plasma by increasing the systemic exposure of active agalsidase, thereby leading to increased cellular levels in disease-relevant tissues. This Phase 2a study design consisted of an open-label, fixed-treatment sequence that evaluated the effects of single oral doses of 150 mg or 450 mg migalastat HCl on the PK and tissue levels of intravenously infused agalsidase (0.2, 0.5, or 1.0 mg/kg) in male Fabry patients. As expected, intravenous administration of agalsidase alone resulted in increased α-Gal A activity in plasma, skin, and peripheral blood mononuclear cells (PBMCs) compared to baseline. Following co-administration of migalastat HCl and agalsidase, α-Gal A activity in plasma was further significantly increased 1.2- to 5.1-fold compared to agalsidase administration alone, in 22 of 23 patients (95.6%). Importantly, similar increases in skin and PBMC α-Gal A activity were seen following co-administration of migalastat HCl and agalsidase. The effects were not related to the administered migalastat HCl dose, as the 150 mg dose of migalastat HCl increased α-Gal A activity to the same extent as the 450 mg dose. Conversely, agalsidase had no effect on the plasma PK of migalastat. No migalastat HCl-related adverse events or drug-related tolerability issues were identified. TRIAL REGISTRATION: ClinicalTrials.gov NCT01196871.

Evaluation of the efficacy and safety of three dosing regimens of agalsidase alfa enzyme replacement therapy in adults with Fabry disease.

PURPOSE: Efficacy and safety of agalsidase alfa at 0.2 mg/kg weekly were compared with 0.2 mg/kg every other week (EOW). Exploratory analyses were performed for 0.4 mg/kg weekly. PATIENTS AND METHODS: This was a 53-week, Phase III/IV, multicenter, open-label study (NCT01124643) in treatment-naïve adults (≥18 years) with Fabry disease. Inclusion criteria were left ventricular hypertrophy at baseline, defined as left ventricular mass indexed to height >50 g/m(2.7) for males and >47 g/m(2.7) for females. Primary endpoint was reduction of left ventricular mass indexed to height as assessed by echocardiography. Secondary endpoints included cardiac (peak oxygen consumption, 6-minute walk test, Minnesota Living with Heart Failure Questionnaire, New York Heart Association classification), renal (Modification of Diet in Renal Disease, estimated glomerular filtration rate), and biomarker (plasma globotriaosylceramide) assessments. Safety endpoints were adverse events and anti-agalsidase alfa antibodies. RESULTS: Twenty patients were randomized to 0.2 mg/kg EOW (mean age, 50.3 years; 70% male), 19 to 0.2 mg/kg weekly (51.8 years; 53% male), and 5 to 0.4 mg/kg weekly (49.4 years; 40% male). The mean change in left ventricular mass indexed to height by Week 53 in the 0.2-mg/kg EOW and weekly groups was 3.2 g/m(2.7) and 0.5 g/m(2.7), with no significant difference between groups. No clinically meaningful changes by Week 53 were found within or between the 0.2-mg/kg groups for peak oxygen consumption, 6-minute walk test, or Minnesota Living with Heart Failure Questionnaire. Two patients in each group improved by ≥1 New York Heart Association classification. No significant differences were found between 0.2 mg/kg EOW and weekly for mean change in estimated glomerular filtration rate (-1.21 mL/min/1.73 m(2) vs -3.32 mL/min/1.73 m(2)) or plasma globotriaosylceramide (-1.05 nmol/mL vs -2.13 nmol/mL), respectively. Infusion-related adverse events were experienced by 25% and 21% in the 0.2-mg/kg EOW and weekly groups. Tachycardia, fatigue, and hypotension were experienced by two or more patients overall. Anti-agalsidase alfa antibodies were detected in 11.4% of patients and neutralizing antibodies in 6.8%. Infusion-related reactions did not appear to be correlated with antibody status. CONCLUSION: No efficacy or safety differences were found when the approved EOW dosage of agalsidase alfa was increased to weekly administration. Exploratory analyses for 0.4 mg/kg weekly showed similar results.