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Velaglucerase alfa商品名为Vpriv,属于生物药物,它属于人细胞源性酶替代疗法（ERT）药物，可作为长期用药治疗1型儿童及成人戈谢病患者。
Less common adverse reactions affecting more than one patient (>2% in the treatment-naïve group and > 3% in patients switched from imiglucerase to VPRIV treatment) were bone pain, tachycardia, rash, urticaria, flushing, hypertension, and hypotension. Adverse Reactions in Pediatric Patients The safety profile of VPRIV was similar between pediatric patients (ages 4 to 17 years) and adult patients. Adverse reactions more commonly seen in pediatric patients compared to adult patients include (>10% difference): rash, aPTT prolonged, and pyrexia. 6.2 Immunogenicity As with all therapeutic proteins, there is a potential for immunogenicity. In clinical studies, 1 of 54 enzyme treatment-naïve patients treated with VPRIV developed IgG class antibodies to VPRIV. In this patient, the antibodies were determined to be neutralizing in an in vitro assay. No hypersensitivity reactions were reported for this patient. It is unknown if the presence of IgG antibodies to VPRIV is associated with a higher risk of infusion reactions. Patients with an immune response to other enzyme replacement therapies who are switching to VPRIV should continue to be monitored for antibodies to VPRIV. Immunogenicity assay results are highly dependent on the sensitivity and specificity of the assay. Additionally, the observed incidence of antibody positivity in an assay may be influenced by several factors, including assay methodology, sample handling, timing of sample collection, concomitant medications, and underlying disease. For these reasons, comparison of the incidence of antibodies to VPRIV with the incidence of antibodies to other products may be misleading. 8 USE IN SPECIFIC POPULATIONS 8.1 Pregnancy Pregnancy Category B Risk Summary There are no adequate and well controlled studies with VPRIV in pregnant women and there is limited experience in pregnant women. However, animal reproduction studies have been conducted for VPRIV. In these animal studies, no fetal harm was observed in rats or rabbits when velaglucerase alfa was administered intravenously during organogenesis at doses with exposures up to 1.8 times and 4.3 times greater than, respectively, the recommended human daily dose. Because animal reproduction studies are not always predictive of human response, VPRIV should be used during pregnancy only if clearly needed. Clinical Considerations Disease-Associated Maternal and Embryo/Fetal Risk Women with Type 1 Gaucher disease have an increased risk of spontaneous abortion, especially if disease symptoms are not treated and controlled pre-conception and during a pregnancy. Pregnancy may exacerbate existing Type 1 Gaucher disease symptoms or result in new disease manifestations. Type 1 Gaucher disease manifestations may lead to adverse pregnancy outcomes including hepatosplenomegaly which can interfere with the normal growth of a pregnancy, and thrombocytopenia which can lead to increased bleeding and possible hemorrhage. Data Animal Data Reproduction studies with velaglucerase alfa have been performed in pregnant rats at intravenous doses up to 17 mg/kg/day (102 mg/m2/day, about 1.8 times greater than the recommended human dose of 60 Units/kg/day or 1.5 mg/kg/day or 55.5 mg/m2/day based on the body surface area). Reproduction studies have been performed in pregnant rabbits at intravenous doses up to 20 mg/kg/day (240 mg/m2/day, about 4.3 times the recommended human dose of 60 Units/kg/day based on the body surface area). These studies did not reveal any evidence of impaired fertility or harm to the fetus due to velaglucerase alfa. A pre- and postnatal development study in rats showed no evidence of any adverse effect on pre-and postnatal development at doses up to 17 mg/kg/day (102 mg/m2/day, about 1.8 times greater than the recommended human dose of 60 Units/kg/day based on the body surface area). 8.3 Nursing Mothers It is not known whether VPRIV is present in human milk. The developmental and health benefits of breastfeeding should be considered along with any potential adverse effects on the breastfed child from the drug or from the underlying maternal condition. Exercise caution when VPRIV is administered to a nursing woman. 8.4 Pediatric Use The safety and effectiveness of VPRIV have been established for enzyme replacement therapy (ERT) in patients between 4 and 17 years of age with type 1 Gaucher disease. Use of VPRIV in this age group is supported by evidence from adequate and well-controlled studies of VPRIV in 74 adult patients and 20 pediatric patients. The safety and efficacy profiles were similar between pediatric and adult patients [see Adverse Reactions (6.1) and Clinical Studies (14)]. The efficacy and safety of VPRIV has not been established in pediatric patients younger than 4 years of age. 8.5 Geriatric Use In clinical studies of VPRIV in Gaucher's disease, a total of 56 VPRIV-treated patients were 65 years of age or older including 10 patients who were 75 years of age or older. Among 205 patients who switched from imiglucerase to VPRIV, 52 patients were 65 years of age or older of which 10 were 75 years and older. The adverse reaction profile in elderly patients was consistent with that previously observed across pediatric and adult patients. Other reported clinical experience has not identified differences in responses between the elderly and younger patients. In general, dose selection for an elderly patient should be approached cautiously, considering potential comorbid conditions. 11 DESCRIPTION The active ingredient of VPRIV is velaglucerase alfa, which is produced by gene activation technology in a human fibroblast cell line. Velaglucerase alfa is a glycoprotein of 497 amino acids; with a molecular weight of approximately 63 kDa. Velaglucerase alfa has the same amino acid sequence as the naturally occurring human enzyme, glucocerebrosidase. Velaglucerase alfa contains 5 potential N-linked glycosylation sites; four of these sites are occupied by glycan chains. Velaglucerase alfa contains predominantly high mannose-type N-linked glycan chains. The high mannose type N-linked glycan chains are specifically recognized and internalized via the mannose receptor present on the surface on macrophages, the cells that accumulate glucocerebroside in Gaucher disease. Velaglucerase alfa catalyzes the hydrolysis of the glycolipid glucocerebroside to glucose and ceramide in the lysosome. VPRIV is a hydrolytic lysosomal glucocerebroside-specific enzyme. VPRIV is dosed by Units/kg, where one Unit of enzyme activity is defined as the quantity of enzyme required to convert one micromole of p-nitrophenyl ß-D-glucopyranoside to p-nitrophenol per minute at 37°C. VPRIV is supplied as a sterile, preservative free, lyophilized powder in single-use vials, each containing 400 Units, for intravenous use. Following reconstitution with Sterile Water for Injection, USP, the solution contains the components listed in Table 2. Table 2: Composition of VPRIV Reconstituted Solution
12.1 Mechanism of Action Gaucher disease is an autosomal recessive disorder caused by mutations in the GBA gene, which results in a deficiency of the lysosomal enzyme beta-glucocerebrosidase. Glucocerebrosidase catalyzes the conversion of the sphingolipid glucocerebroside into glucose and ceramide. The enzymatic deficiency causes an accumulation of glucocerebroside primarily in the lysosomal compartment of macrophages, giving rise to foam cells or "Gaucher cells". Velaglucerase alfa catalyzes the hydrolysis of glucocerebroside, reducing the amount of accumulated glucocerebroside. In clinical trials VPRIV reduced spleen and liver size, and improved anemia and thrombocytopenia. In this lysosomal storage disorder (LSD), clinical features are reflective of the accumulation of Gaucher cells in the liver, spleen, bone marrow, and other organs. The accumulation of Gaucher cells in the liver and spleen leads to organomegaly. Presence of Gaucher cells in the bone marrow and spleen lead to clinically significant anemia and thrombocytopenia. 12.3 Pharmacokinetics In a multicenter study conducted in pediatric (N=7, 4 to 17 years old) and adult (N=15, 19 to 62 years old) patients with type 1 Gaucher disease, pharmacokinetic evaluations were performed at Weeks 1 and 37 following 60-minute intravenous infusions of VPRIV 60 Units/kg every other week. Serum velaglucerase alfa concentrations declined rapidly with a mean half life of 11 to 12 minutes. The mean velaglucerase alfa clearance ranged from 6.72 to 7.56 mL/min/kg. The mean volume of distribution at steady state ranged from 82 to 108 mL/kg (8.2% to 10.8% of body weight). No accumulation or change in velaglucerase alfa pharmacokinetics over time from Weeks 1 to 37 was observed upon multiple-dosing 60 Units/kg every other week. Based on the limited data, there were no notable pharmacokinetic differences between male and female patients in this study. The effect of age on pharmacokinetics of velaglucerase alfa was inconclusive. The effect of anti-drug antibody formation on the pharmacokinetic parameters of velaglucerase alfa is unknown. 13 NONCLINICAL TOXICOLOGY 13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility Long-term studies in animals to evaluate carcinogenic potential or studies to evaluate mutagenic potential have not been performed with velaglucerase alfa. In a male and female fertility study in rats, velaglucerase alfa did not cause any significant adverse effect on male or female fertility parameters up to a maximum dose of 17 mg/kg/day (102 mg/m2/day, about 1.8 times the recommended human dose of 60 Units/kg/day based on the body surface area). 14 CLINICAL STUDIES 14.1 Overview of Clinical Studies of VPRIV for Gaucher Disease The efficacy of VPRIV was assessed in three clinical trials in a total of 99 patients with type 1 Gaucher disease: 82 patients age 4 years and older received VPRIV and 17 patients age 3 years and older received imiglucerase. Studies I and II were conducted in patients who were not currently receiving Gaucher disease-specific therapy. Study III was conducted in patients who were receiving imiglucerase treatment immediately before starting VPRIV. The long-term safety of VPRIV was assessed in Study IV, an open-label extension trial in a total of 93 patients with type 1 Gaucher disease ages 3 years and older. Patients who had completed Studies I to III were eligible to participate in Study IV. In Studies I through IV, VPRIV was administered intravenously over 60 minutes at a maximum dose of 60 Units/kg every other week. Doses above 60 Units/kg were not studied in these trials. 14.2 Clinical Trials of VPRIV as Initial Therapy Study I was a 12-month, randomized, double-blind, parallel-dose-group, multinational trial in 25 patients age 4 years and older with Gaucher disease-related anemia and either thrombocytopenia or organomegaly. Patients were not allowed to have had disease-specific therapy for at least the previous 30 months; all but one had no prior therapy. The mean age was 26 years and 60% were male. Patients were randomized to receive VPRIV at a dose of either 45 Units/kg (N=13) or 60 Units/kg (N=12) every other week. The recommended starting dose in naïve patients is 60 Units/kg. The 45 Units/kg dosage is not recommended as a starting dose in naïve patients [see Dosage and Administration (2.1)]. At baseline, mean hemoglobin concentration was 10.6 g/dL, mean platelet count was 97 × 109/L, mean liver volume was 3.6 % of body weight (% BW), and mean spleen volume was 2.9 % BW For all studies, liver and spleen volumes were measured by MRI. The changes in clinical parameters after 12 months of treatment are shown in Table 3. The observed change from baseline in the primary endpoint, hemoglobin concentration, was considered to be clinically meaningful in the 60 Units/kg dose, in light of the natural history of untreated Gaucher disease. Table 3: Mean Change from Baseline to Month 12 for Clinical Parameters in Patients with Type 1 Gaucher Disease Initiating Therapy with VPRIV in Study I
Statistically significant changes from baseline after adjusting for performing multiple tests Primary study endpoint was hemoglobin concentration change in the 60 Units/kg group, p < 0.001 Study II was a 9-month, randomized, double-blind, active-controlled (imiglucerase), parallel-group, multinational study in 34 patients age 4 years and older. Patients were required to have Gaucher disease-related anemia and either thrombocytopenia or organomegaly. Patients were not allowed to have had disease-specific therapy for at least the previous 12 months. The mean age was 30 years and 53% were female; the youngest patient who received VPRIV was age 4 years. Patients were randomized to receive either 60 Units/kg of VPRIV (N=17) or 60 Units/kg of imiglucerase (N=17) every other week. At baseline, the mean hemoglobin concentration was 11.0 g/dL, mean platelet count was 171 × 109/L, and mean liver volume was 4.3 % BW. For the patients who had not had splenectomy (7 in each group) the mean spleen volume was 3.4 % BW. After 9 months of treatment, the mean absolute increase from baseline in hemoglobin concentration was 1.6 g/dL ± 0.2 (SE) for patients treated with VPRIV. The mean treatment difference in change from baseline to 9 months [VPRIV – imiglucerase] was 0.1 g/dL ± 0.4 (SE). In both studies, examination of age and gender subgroups did not identify differences in response to VPRIV among these subgroups. The number of non-Caucasian patients in these studies was too small to adequately assess any difference in effects by race. In Study IV, treatment naïve patients were administered VPRIV. Treatment-naïve patients continued to show improvements in clinical parameters (hemoglobin concentration, platelet count, liver volume, and spleen volume) compared with baseline for up to 60 months of treatment with ERT. 14.3 Clinical Trial in Patients Switching from Imiglucerase Treatment to VPRIV Study III was a 12-month, open-label, single-arm, multinational study in 40 patients age 9 years and older who had been receiving treatment with imiglucerase at doses ranging between 15 Units/kg to 60 Units/kg for a minimum of 30 consecutive months. Patients also were required to have a stable biweekly dose of imiglucerase for at least 6 months prior to enrollment. The mean age was 36 years and 55% were female. Imiglucerase therapy was stopped, and treatment with VPRIV was administered every other week at the same number of units as the patient's previous imiglucerase dose. Adjustment of dosage was allowed by study criteria if needed in order to maintain clinical parameters [see Dosage and Administration (2.2)]. Hemoglobin concentrations and platelet counts remained stable on average through 12 months of VPRIV treatment. After 12 months of treatment with VPRIV the median hemoglobin concentration was 13.5 g/dL (range: 10.8, 16.1) vs. the baseline value of 13.8 g/dL (range: 10.4, 16.5), and the median platelet count after 12 months was 174 × 109/L (range: 24, 408) vs. the baseline value of 162 × 109/L (range: 29, 399). No patient required dosage adjustment during the 12-month treatment period. In Study IV, patients who had previously been receiving imiglucerase treatment were administered VPRIV. Patients previously treated with imiglucerase maintained stability in clinical parameters (hemoglobin concentration, platelet count, liver volume, and spleen volume) compared with baseline for up to 60 months of treatment with ERT. 16 HOW SUPPLIED/STORAGE AND HANDLING 16.1 How Supplied VPRIV is a sterile, preservative free, lyophilized powder requiring reconstitution and further dilution prior to use. It is supplied in individually packaged glass vials, which are closed with a butyl rubber stopper with a fluoro-resin coating and are sealed with an aluminum overseal with a flip-off plastic cap. The vials are intended for single use only. VPRIV is available as: 400 Units/vial NDC 54092-701-04. 16.2 Storage Store VPRIV at 2 °C to 8°C (36°F to 46°F). Do not use VPRIV after the expiration date on the vial. Do not freeze. Protect vial from light. 17 PATIENT COUNSELING INFORMATION Advise patients that VPRIV is a treatment that is given intravenously every other week. The infusion typically takes up to 60 minutes. Advise patients that VPRIV may cause hypersensitivity reactions [see Warnings and Precautions (5.1)]. | |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
