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Cell cycle progression is disrupted in murine MPS VII growth plate chondrocytes
Abstracts / Molecular Genetics and Metabolism 120 (2016) S17–S145
disease seen in 16/29. While idursulfase has significantly impacted MPS II patients’ survival, there is still significant morbidity with the potential range of neurological outcomes being under-represented in literature. doi:10.1016/j.ymgme.2016.11.055
47 Long-term benefit of sebelipase alfa over 76 weeks in children and adults with lysosomal acid lipase deficiency (LALD) “ARISE” Barbara K. Burtona, Sachin Marulkarb, Mark Friedmanb, Radhika Tripuranenib, Katryn N. Furuyac,d, aNorthwestern University, Feinberg School of Medicine, Chicago, IL, United States, bAlexion Pharmaceuticals, Inc., New Haven, CT, United States, cAlfred I. duPont Hospital for Children, Wilmington, DE, United States, dMayo Clinic, Rochester, MN, United States LALD is a progressive multisystem disease that causes cirrhosis, severe dyslipidemia, and early-onset atherosclerosis. In the phase 3 ARISE study (NCT01757184) ALT levels and multiple secondary outcome measures significantly improved after 20 weeks of sebelipase alfa (SA) treatment in patients with LALD. Patients (N=66; median age 13 y, range 4-58 y) were randomized to placebo (PBO) or SA, 1 mg/kg every other week, for 20 weeks; 65 patients entered an ongoing, openlabel extension phase in which all receive SA. We now report efficacy data after 76 weeks of treatment and safety results from the open-label period after 86-152 weeks of treatment. ALT and AST normalization were achieved by 52% (32/61) and 65% (37/57) of patients, respectively. PBO recipients who crossed over to SA exhibited marked and sustained improvements in ALT and AST that mirrored improvements in the SA group during the double-blind phase. Patients who continued receiving SA in the open-label period sustained the improvements achieved in the double-blind period. Mean baseline LDL-C (199.2 mg/dL), non-HDLC (230.0 mg/dL), and triglycerides (153.9 mg/dL) decreased by −28%, −27%, and −17%, respectively, after 76 weeks of SA exposure; mean HDL-C (baseline 32.5 mg/dL) increased by 23%. Most AEs in the openlabel period were mild to moderate in severity. Most common: headache, nasopharyngitis, cough, and pyrexia. Four patients had serious AEs (1 treatment-related, an infusion-associated reaction). Twelve patients (19%) experienced infusion-associated reactions (mild or moderate in all except 1 patient). No patient discontinued due to an AE. Six (9%) patients had ≥1 positive anti-drug antibody (ADA) sample; two developed neutralizing antibodies. SA was well tolerated; the longterm safety profile was similar to the profile seen during the doubleblind portion. Long-term treatment with SA has produced early, rapid, and sustained improvements in markers of liver injury and lipid abnormalities. (Sponsored by Alexion Pharmaceuticals, Inc.) doi:10.1016/j.ymgme.2016.11.056
48 Cell cycle progression is disrupted in murine MPS VII growth plate chondrocytes Sharon Byersa,b, Zhirui Jiangb, Clare Reichsteinb, Ainslie L.K. DerrickRobertsa,b, aSA Pathology (WCH site), North Adelaide, Australia, bThe University of Adelaide, Adelaide, Australia Chondrocyte number is significantly decreased in the proliferative (PZ) and hypertrophic (HZ) zone of MPS VII growth plate, contributing to shortened bone length. The cell cycle is tightly regulated in the growth plate as chondrocytes enter the cycle to divide and then exit the cycle to hypertrophy. Immunohistochemistry of normal growth plate
S33
indicated that cells throughout the growth plate are positive for Ki67 antigen, a marker for all active phases of the cycle and the number of cells positive for Ki67 increased significantly in MPS VII. The G1 phase marker Cyclin D1, and M phase marker phosphorylated histone H3 (pHisH3) were predominantly observed in normal PZ indicating progression to mitotic division. These markers were not observed in the HZ where cells expressed p57kip2 indicating an exit from the cell cycle. In contrast, a decrease in the number of PZ chondrocytes expressing pHisH3 was observed in MPS VII (66% of normal) while MPS VII HZ chondrocytes continued to express cyclinD1 but fewer chondrocytes were positive for p57kip2 (51% of normal). Thus in the MPS VII growth plate more cells had entered the cell cycle but fewer cells were capable of continuing to mitosis or to exit the cell cycle. This was supported by real-time PCR showing a 2-fold reduction in the expression of Ihh in MPS VII and a 4.4-and 3.1-fold increase in PTHrPR and Sox9. Thus cell cycle progression is disrupted in MPS VII growth plate chondrocytes, decreasing proliferation and delaying the conversion from the proliferative to hypertrophic phenotype, both of which contribute to impaired linear bone growth in MPS VII mice. Studies of the regulation of cell division and hypertrophic maturation in MPS VII are ongoing to understand the mechanism behind reduced bone length in MPS and to generate potential therapies for growth retardation in MPS patients. doi:10.1016/j.ymgme.2016.11.057
49 Long term enzyme replacement therapy for Fabry disease: effectiveness on heart, kidney and brain Gustavo H Cabreraa, Juan Manuel Politeib, aCentro Cardiovascular Bolivar, Pilar, Buenos Aires, Argentina, bFundacion Para el Estudio de Enfermedades Neurometabolicas (FESEN), Buenos Aires, Argentina Background: Fabry disease (FD) is an X-linked lysosomal storage disorder caused by α-galactosidase A deficiency leading to renal, cardiac, cerebrovascular disease and premature death. Treatment with αgalactosidase A (enzyme replacement therapy, ERT) stabilizes disease in some patients, but long term effectiveness is unclear. Objective: the aim of this study was to determine prospectively whether ERT in patients with FD affects progression towards ‘hard’ clinical end-points. Methods: A total of 39 patients with genetically proven Fabry disease, (mean age31.7±12.8 years; n = 24 men) were treated prospectively with ERT for 68.2±37 months. The main outcomes were the occurrence of major cardiac events, stroke, end-stage renal disease and death. Secondary outcomes included changes in myocardial left ventricular (LV) wall thickness, changes in estimated glomerular filtration rate (eGFR) and proteinuria, new TIA and change in neuropathic pain. Results: During the follow-up 8 events occurred in 5 patients (n = 2 deaths, n = 4 cases of ESRD and n = 1 atrial fibrillation), 4 of them were males and only 1 female who suffered an atrial fibrillation. Sudden death, stroke or TIA didn´t occurred. Four (40%) from 10 males with baseline LVH reduced LVMI , 2 stabilized and 4 increased LVMI. Over 9 females only 1 patient increased LVMI, all the rest patients reduced or stabilized their LVMI. Estimated GFR was stable in 30 patients (17 males and 13 females). Conclusions: the favorable long term outcome of this cohort is related to age. Most of our patients were young at baseline with no advanced Fabry disease at baseline. These findings reinforced the necessity of initiate ERT the soon as possible before disease progressed to irreversible organ damage.
doi:10.1016/j.ymgme.2016.11.058
disease seen in 16/29. While idursulfase has significantly impacted MPS II patients’ survival, there is still significant morbidity with the potential range of neurological outcomes being under-represented in literature. doi:10.1016/j.ymgme.2016.11.055
47 Long-term benefit of sebelipase alfa over 76 weeks in children and adults with lysosomal acid lipase deficiency (LALD) “ARISE” Barbara K. Burtona, Sachin Marulkarb, Mark Friedmanb, Radhika Tripuranenib, Katryn N. Furuyac,d, aNorthwestern University, Feinberg School of Medicine, Chicago, IL, United States, bAlexion Pharmaceuticals, Inc., New Haven, CT, United States, cAlfred I. duPont Hospital for Children, Wilmington, DE, United States, dMayo Clinic, Rochester, MN, United States LALD is a progressive multisystem disease that causes cirrhosis, severe dyslipidemia, and early-onset atherosclerosis. In the phase 3 ARISE study (NCT01757184) ALT levels and multiple secondary outcome measures significantly improved after 20 weeks of sebelipase alfa (SA) treatment in patients with LALD. Patients (N=66; median age 13 y, range 4-58 y) were randomized to placebo (PBO) or SA, 1 mg/kg every other week, for 20 weeks; 65 patients entered an ongoing, openlabel extension phase in which all receive SA. We now report efficacy data after 76 weeks of treatment and safety results from the open-label period after 86-152 weeks of treatment. ALT and AST normalization were achieved by 52% (32/61) and 65% (37/57) of patients, respectively. PBO recipients who crossed over to SA exhibited marked and sustained improvements in ALT and AST that mirrored improvements in the SA group during the double-blind phase. Patients who continued receiving SA in the open-label period sustained the improvements achieved in the double-blind period. Mean baseline LDL-C (199.2 mg/dL), non-HDLC (230.0 mg/dL), and triglycerides (153.9 mg/dL) decreased by −28%, −27%, and −17%, respectively, after 76 weeks of SA exposure; mean HDL-C (baseline 32.5 mg/dL) increased by 23%. Most AEs in the openlabel period were mild to moderate in severity. Most common: headache, nasopharyngitis, cough, and pyrexia. Four patients had serious AEs (1 treatment-related, an infusion-associated reaction). Twelve patients (19%) experienced infusion-associated reactions (mild or moderate in all except 1 patient). No patient discontinued due to an AE. Six (9%) patients had ≥1 positive anti-drug antibody (ADA) sample; two developed neutralizing antibodies. SA was well tolerated; the longterm safety profile was similar to the profile seen during the doubleblind portion. Long-term treatment with SA has produced early, rapid, and sustained improvements in markers of liver injury and lipid abnormalities. (Sponsored by Alexion Pharmaceuticals, Inc.) doi:10.1016/j.ymgme.2016.11.056
48 Cell cycle progression is disrupted in murine MPS VII growth plate chondrocytes Sharon Byersa,b, Zhirui Jiangb, Clare Reichsteinb, Ainslie L.K. DerrickRobertsa,b, aSA Pathology (WCH site), North Adelaide, Australia, bThe University of Adelaide, Adelaide, Australia Chondrocyte number is significantly decreased in the proliferative (PZ) and hypertrophic (HZ) zone of MPS VII growth plate, contributing to shortened bone length. The cell cycle is tightly regulated in the growth plate as chondrocytes enter the cycle to divide and then exit the cycle to hypertrophy. Immunohistochemistry of normal growth plate
S33
indicated that cells throughout the growth plate are positive for Ki67 antigen, a marker for all active phases of the cycle and the number of cells positive for Ki67 increased significantly in MPS VII. The G1 phase marker Cyclin D1, and M phase marker phosphorylated histone H3 (pHisH3) were predominantly observed in normal PZ indicating progression to mitotic division. These markers were not observed in the HZ where cells expressed p57kip2 indicating an exit from the cell cycle. In contrast, a decrease in the number of PZ chondrocytes expressing pHisH3 was observed in MPS VII (66% of normal) while MPS VII HZ chondrocytes continued to express cyclinD1 but fewer chondrocytes were positive for p57kip2 (51% of normal). Thus in the MPS VII growth plate more cells had entered the cell cycle but fewer cells were capable of continuing to mitosis or to exit the cell cycle. This was supported by real-time PCR showing a 2-fold reduction in the expression of Ihh in MPS VII and a 4.4-and 3.1-fold increase in PTHrPR and Sox9. Thus cell cycle progression is disrupted in MPS VII growth plate chondrocytes, decreasing proliferation and delaying the conversion from the proliferative to hypertrophic phenotype, both of which contribute to impaired linear bone growth in MPS VII mice. Studies of the regulation of cell division and hypertrophic maturation in MPS VII are ongoing to understand the mechanism behind reduced bone length in MPS and to generate potential therapies for growth retardation in MPS patients. doi:10.1016/j.ymgme.2016.11.057
49 Long term enzyme replacement therapy for Fabry disease: effectiveness on heart, kidney and brain Gustavo H Cabreraa, Juan Manuel Politeib, aCentro Cardiovascular Bolivar, Pilar, Buenos Aires, Argentina, bFundacion Para el Estudio de Enfermedades Neurometabolicas (FESEN), Buenos Aires, Argentina Background: Fabry disease (FD) is an X-linked lysosomal storage disorder caused by α-galactosidase A deficiency leading to renal, cardiac, cerebrovascular disease and premature death. Treatment with αgalactosidase A (enzyme replacement therapy, ERT) stabilizes disease in some patients, but long term effectiveness is unclear. Objective: the aim of this study was to determine prospectively whether ERT in patients with FD affects progression towards ‘hard’ clinical end-points. Methods: A total of 39 patients with genetically proven Fabry disease, (mean age31.7±12.8 years; n = 24 men) were treated prospectively with ERT for 68.2±37 months. The main outcomes were the occurrence of major cardiac events, stroke, end-stage renal disease and death. Secondary outcomes included changes in myocardial left ventricular (LV) wall thickness, changes in estimated glomerular filtration rate (eGFR) and proteinuria, new TIA and change in neuropathic pain. Results: During the follow-up 8 events occurred in 5 patients (n = 2 deaths, n = 4 cases of ESRD and n = 1 atrial fibrillation), 4 of them were males and only 1 female who suffered an atrial fibrillation. Sudden death, stroke or TIA didn´t occurred. Four (40%) from 10 males with baseline LVH reduced LVMI , 2 stabilized and 4 increased LVMI. Over 9 females only 1 patient increased LVMI, all the rest patients reduced or stabilized their LVMI. Estimated GFR was stable in 30 patients (17 males and 13 females). Conclusions: the favorable long term outcome of this cohort is related to age. Most of our patients were young at baseline with no advanced Fabry disease at baseline. These findings reinforced the necessity of initiate ERT the soon as possible before disease progressed to irreversible organ damage.
doi:10.1016/j.ymgme.2016.11.058