Elaprase(Idursulfase Solution)获批用于治疗粘多糖贮积症Ⅱ型 (Hunter 综合症)
Across studies, serious adverse reactions were reported in a total of 5 patients who received 0.5 mg/kg weekly or every other week. Four patients experienced a hypoxic episode during one or several infusions, which necessitated oxygen therapy in 3 patients with severe underlying obstructive airway disease (2 with a pre-existing tracheostomy). The most severe episode occurred in a patient with a febrile respiratory illness and was associated with hypoxia during the infusion, resulting in a short seizure. In the fourth patient, who had less severe underlying disease, spontaneous resolution occurred shortly after the infusion was interrupted. These events did not recur with subsequent infusions using a slower infusion rate and administration of pre-infusion medicinal products, usually low-dose steroids, antihistamine, and beta-agonist nebulisation. The fifth patient, who had pre-existing cardiopathy, was diagnosed with ventricular premature complexes and pulmonary embolism during the study. There have been post-marketing reports of anaphylactoid/anaphylactic reactions. Please see section 4.4 for further information. Patients with complete deletion/large rearrangement genotype have a higher probability of developing infusion related adverse events (see section 4.4). Immunogenicity Across 4 clinical studies (TKT008, TKT018, TKT024 and TKT024EXT), 53/107 patients (50%) developed anti-idursulfase IgG antibodies at some point. The overall neutralizing antibody rate was 26/107 patients (24%). In the post-hoc immunogenicity analysis of data from TKT024/024EXT studies, 51% (32/63) patients treated with 0.5mg/kg weekly Elaprase had at least 1 blood sample that tested positive for anti-Elaprase antibodies, and 37 % (23/63) tested positive for antibodies on at least 3 consecutive study visits. Twenty-one percent (13/63) tested positive for neutralizing antibodies at least once and 13 % (8/63) tested positive for neutralizing antibodies on at least 3 consecutive study visits. Clinical study HGT-ELA-038 evaluated immunogenicity in children 16 months to 7.5 years of age. During the 53-week study, 67.9% (19 of 28) of patients had at least one blood sample that tested positive for anti-Elaprase antibodies, and 57.1% (16 of 28) tested positive for antibodies on at least three consecutive study visits. Fifty-four percent of patients tested positive for neutralizing antibodies at least once and half of the patients tested positive for neutralizing antibodies on at least three consecutive study visits. All patients with the complete deletion/large rearrangement genotype developed antibodies, and the majority of them (7/8) also tested positive for neutralizing antibodies on at least 3 consecutive occasions. All patients with the frameshift/splice site mutation genotype developed antibodies and 4/6 also tested positive for neutralizing antibodies on at least 3 consecutive study visits. Antibody-negative patients were found exclusively in the missense mutation genotype group. (See sections 4.4 and 5.1) Paediatric population Adverse reactions reported in the paediatric population were, in general, similar to those reported in adults. Reporting of suspected adverse reactions Reporting suspected adverse reactions after authorisation of the medicinal product is important. It allows continued monitoring of the benefit/risk balance of the medicinal product. Healthcare professionals are asked to report any suspected adverse reactions via: United Kingdom: Yellow Card Scheme Website: www.mhra.gov.uk/yellowcard Ireland: HPRA Pharmacovigilance Earlsfort Terrace IRL - Dublin 2 Tel: +353 1 6764971 Fax: +353 1 6762517 Website: www.hpra.ie e-mail: medsafety@hpra.ie 4.9 Overdose There is no experience with overdoses of Elaprase. 5. Pharmacological properties 5.1 Pharmacodynamic properties Pharmacotherapeutic group: Other alimentary tract and metabolism products – enzymes, ATC code: A16AB09. Mechanism of action Hunter syndrome is an X-linked disease caused by insufficient levels of the lysosomal enzyme iduronate-2-sulfatase. Iduronate-2-sulfatase functions to catabolize the glycosaminoglycans (GAG) dermatan sulfate and heparan sulfate by cleavage of oligosaccharide-linked sulfate moieties. Due to the missing or defective iduronate-2-sulfatase enzyme in patients with Hunter syndrome, glycosaminoglycans progressively accumulate in the cells, leading to cellular engorgement, organomegaly, tissue destruction, and organ system dysfunction. Idursulfase is a purified form of the lysosomal enzyme iduronate-2-sulfatase, produced in a human cell line providing a human glycosylation profile, which is analogous to the naturally occurring enzyme. Idursulfase is secreted as a 525 amino acid glycoprotein and contains 8 N-linked glycosylation sites that are occupied by complex, hybrid, and high-mannose type oligosaccharide chains. Idursulfase has a molecular weight of approximately 76 kD. Treatment of Hunter syndrome patients with intravenous Elaprase provides exogenous enzyme for uptake into cellular lysosomes. Mannose-6-phosphate (M6P) residues on the oligosaccharide chains allow specific binding of the enzyme to the M6P receptors on the cell surface, leading to cellular internalization of the enzyme, targeting to intracellular lysosomes and subsequent catabolism of accumulated GAG. Clinical efficacy and safety The safety and efficacy of Elaprase has been shown in three clinical studies: two randomised, placebo-controlled clinical studies (TKT008 and TKT024) in adults and children above the age of 5 years and one open-label, safety study (HGT-ELA-038) in children 16 months to 7.5 years of age. A total of 108 male Hunter syndrome patients with a broad spectrum of symptoms were enrolled in the two randomized, placebo-controlled clinical studies, 106 continued treatment in two open-label, extension studies. In a 52-week, randomized, double-blind, placebo-controlled clinical study, 96 patients between the ages of 5 and 31 years received Elaprase 0.5 mg/kg every week (n=32) or 0.5 mg/kg every other week (n=32), or placebo (n=32). The study included patients with a documented deficiency in iduronate-2-sulfatase enzyme activity, a percent predicted FVC <80%, and a broad spectrum of disease severity. The primary efficacy endpoint was a two-component composite score based on the sum of the ranks of the change from baseline to the end of the study in the distance walked during six minutes (6-minute walk test or 6MWT) as a measure of endurance, and % predicted forced vital capacity (FVC) as a measure of pulmonary function. This endpoint differed significantly from placebo for patients treated weekly (p=0.0049). Additional clinical benefit analyses were performed on individual components of the primary endpoint composite score, absolute changes in FVC, changes in urine GAG levels, liver and spleen volumes, measurement of forced expiratory volume in 1 second (FEV1), and changes in left ventricular mass (LVM).
Urine GAG levels were normalized below the upper limit of normal (defined as 126.6 µg GAG/mg creatinine) in 50% of the patients receiving weekly treatment. Of the 25 patients with abnormally large livers at baseline in the weekly treatment group, 80% (20 patients) had reductions in liver volume to within the normal range by the end of the study. Of the 9 patients in the weekly treatment group with abnormally large spleens at baseline, 3 had spleen volumes that normalized by the end of the study. Approximately half of the patients in the weekly treatment group (15 of 32; 47%) had left ventricular hypertrophy at baseline, defined as LVM index >103 g/m2. Of these 6 (40%) had normalised LVM by the end of the study. All patients received weekly idursulfase up to 3.2 years in an extension to this study (TKT024EXT). Among patients who were originally randomised to weekly idursulfase in TKT024, mean maximum improvement in distance walked during six minutes occurred at Month 20 and mean percent predicted FVC peaked at Month 16. Among all patients, statistically significant mean increases from treatment baseline (TKT024 baseline for TKT024 idursulfase patients and Week 53 baseline for TKT024 placebo patients) were seen in the distance walked 6MWT at the majority of time points tested, with significant mean and percent increases ranging from 13.7m to 41.5m (maximum at Month 20) and from 6.4% to 13.3% (maximum at Month 24) respectively. At most time points tested, patients who were from the original TKT024 weekly treatment group improved their walking distance to a greater extent that patients in the other 2 treatment groups. Among all patients, mean % predicted FVC was significantly increased at Month 16, although by Month 36, it was similar to the baseline. Patients with the most severe pulmonary impairment at baseline (as measured by % predicted FVC) tended to show the least improvement. Statistically significant increases from treatment baseline in absolute FVC volume were seen at most visits for all treatment groups combined and for each of the prior TKT024 treatment groups. Mean changes from 0.07 l to 0.31 l and percent ranged from 6.3% to 25.5% (maximum at Month 30). The mean and percent changes from treatment baseline were greatest in the group of patients from the TKT024 study who had received the weekly dosing, across all time points. At their final visit 21/31 patients in the TKT024 Weekly group, 24/32 in the TKT024 EOW group and 18/31 patients in the TKT024 placebo group had final normalised urine GAG levels that were below the upper limit of normal. Changes in urinary GAG levels were the earliest signs of clinical improvement with idursulfase treatment and the greatest decreases in urinary GAG were seen within the first 4 months of treatment in all treatment groups; changes from Month 4 to 36 were small. The higher the urinary GAG levels at baseline, the greater the magnitude of decreases in urinary GAG with idursulfase treatment. The decreases in liver and spleen volumes observed at the end of study TKT024 (week 53) were maintained during the extension study (TKT024EXT) in all patients regardless of the prior treatment they had been assigned. Liver volume normalised by Month 24 for 73% (52 out of 71) of patients with hepatomegaly at baseline. In addition, mean liver volume decreased to a near maximum extent by Month 8 in all patients previously treated, with a slight increase observed at Month 36. The decreases in mean liver volume were seen regardless of age, disease severity, IgG antibody status or neutralising antibody status. Spleen volume normalised by Months 12 and 24 for 9.7% of patients in the TKT024 Weekly group with splenomegaly. Mean cardiac LVMI remained stable over 36 months of idursulfase treatment within each TKT024 treatment group. In a post-hoc analysis of immunogenicity in studies TKT024 and TKT024EXT (see section 4.8), patients were shown to have either the mis-sense mutation or the frameshift / nonsense mutation. After 105 weeks of exposure to Elaprase, neither antibody status nor genotype affected reductions in liver and spleen size or distance walked in the 6-minute walk test or forced vital capacity measurements. Patients who tested antibody-positive displayed less reduction in urinary output of glycosaminoglycans than antibody-negative patients. The longer-term effects of antibody development on clinical outcomes have not been established. Study HGT-ELA-038 was an open-label, multicenter, single-arm study of Elaprase infusions in male Hunter syndrome patients between the age of 16 months and 7.5 years. Elaprase treatment resulted in up to 60% reduction in urine output of glycosaminoglycans and in reductions of liver and spleen size: results were comparable to those found in study TKT024. Reductions were evident by week 18 and were maintained to week 53. Patients who developed a high titre of antibodies displayed less response to Elaprase as assessed by urine output of glycosaminoglycans and by liver and spleen size. Analyses of genotypes of patients in study HGT-ELA-038 Patients were classified into the following groups: missense (13), complete deletion/large rearrangement (8), and frameshift/ splice site mutations (5). One patient was unclassified / unclassifiable. The complete deletion / large rearrangement genotype was most commonly associated with development of high titre of antibodies and neutralising antibodies to Elaprase and was most likely to display a muted response to Elaprase. It was not possible, however, to accurately predict individual clinical outcome based on antibody response or genotype. No clinical data exist demonstrating a benefit on the neurological manifestations of the disorder. This medicinal product has been authorised under “exceptional circumstances”. This means that due to the rarity of the disease it has not been possible to obtain complete information on this medicinal product. The European Medicines Agency (EMA) will review any new information which may become available every year and this SmPC will be updated as necessary. 5.2 Pharmacokinetic properties Idursulfase is taken up by selective receptor-mediated mechanisms involving binding to mannose 6-phosphate receptors. Upon internalization by cells, it is localized within cellular lysosomes, thereby limiting distribution of the protein. Degradation of idursulfase is achieved by generally well understood protein hydrolysis mechanisms to produce small peptides and amino acids, consequently renal and liver function impairment is not expected to affect the pharmacokinetics of idursulfase. Pharmacokinetic parameters measured during the first infusion at week 1 of studies TKT024 (0.5 mg/kg weekly arm) and HGT-ELA-038 are displayed in the tables below as a function of age and body weight. PK parameters at week 1 as a function of age in Studies TKT024 and HGT-ELA-038
PK parameters at week 1 as a function of body weight in studies TKT024 and HGT-ELA-038
Overall, there was no apparent trend in either systemic exposure or clearance rate of Elaprase with respect to either age or body weight. 5.3 Preclinical safety data Nonclinical data reveal no special hazard for humans based on conventional studies of safety pharmacology, single dose toxicity, repeated dose toxicity, toxicity to reproduction and development and to male fertility. Animal studies do not indicate direct or indirect harmful effects with respect to pregnancy, embryonal/ foetal development, parturition or postnatal development. Animal studies have shown excretion of idursulfase in breast milk. 6. Pharmaceutical particulars 6.1 List of excipients Polysorbate 20 Sodium chloride Sodium phosphate dibasic, heptahydrate Sodium phosphate monobasic, monohydrate Water for injections 6.2 Incompatibilities This medicinal product must not be mixed with other medicinal products except those mentioned in section 6.6. 6.3 Shelf life 2 years Chemical and physical in-use stability has been demonstrated for 8 hours at 25°C. Diluted product From a microbiological safety point of view, the diluted product should be used immediately. If not used immediately, in-use storage times and conditions prior to use are the responsibility of the user and should not be longer than 24 hours at 2 to 8°C. 6.4 Special precautions for storage Store in a refrigerator (2°C – 8°C). Do not freeze. For storage conditions after dilution of the medicinal product, see section 6.3. 6.5 Nature and contents of container 3 ml of concentrate for solution for infusion in a 5 ml vial (type I glass) with a stopper (fluoro-resin coated butyl rubber), one piece seal and blue flip-off cap. Pack sizes of 1, 4 and 10 vials. Not all pack sizes may be marketed. 6.6 Special precautions for disposal and other handling Each vial of Elaprase is intended for single use only and contains 6 mg of idursulfase in 3 ml of solution. Elaprase is for intravenous infusion and must be diluted in sodium chloride 9 mg/ml (0.9%) solution for infusion prior to use. It is recommended to deliver the total volume of infusion using a 0.2 µm in line filter. Elaprase should not be infused with other products in the infusion tubing. Determine the number of vials to be diluted based on the individual patient's weight and the recommended dose of 0.5 mg/kg. Do not use if the solution in the vials is discoloured or if particulate matter is present. Do not shake. Withdraw the calculated volume of Elaprase from the appropriate number of vials. Dilute the total volume required of Elaprase in 100 ml of 9 mg/ml (0.9%) sodium chloride solution for infusion. Care must be taken to ensure the sterility of the prepared solutions since Elaprase does not contain any preservative or bacteriostatic agent; aseptic technique must be observed. Once diluted, the solution should be mixed gently, but not shaken. Any unused medicinal product or waste material should be disposed of in accordance with local requirements. 7. Marketing authorisation holder Shire Human Genetic Therapies AB, Svärdvägen 11D, 182 33 Danderyd, Sweden 8. Marketing authorisation number(s) EU/1/06/365/001-003 9. Date of first authorisation/renewal of the authorisation Date of first authorisation: January 2007 Date of latest renewal: 03 October 2011 10. Date of revision of the text 22 October 2015 Detailed information on this medicinal product is available on the website of the European Medicines Agency http://www.ema.europa.eu. ------------------------------------------------------ 产地国家:德国 原产地英文商品名: ELAPRASE 6MG/3ML/VIAL 原产地英文药品名: IDURSULFASE 中文参考商品译名: ELAPRASE 6毫克/3毫升/瓶 中文参考药品译名: 艾杜硫酶 生产厂家中文参考译名: SHIRE 生产厂家英文名: SHIRE
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