Vpriv

2.1 Recommendations Prior to VPRIV treatment

Administration of VPRIV should be supervised by a healthcare provider knowledgeable in the management of hypersensitivity reactions including anaphylaxis [see Warnings and Precautions (5.1)].

Initiate VPRIV in a healthcare setting with appropriate medical monitoring and support measures, including access to cardiopulmonary resuscitation equipment [see Warnings and Precautions (5.1)].

2.2 Recommended Starting Dosage in Patients Naïve to Enzyme Replacement Therapy

The recommended starting VPRIV dosage in naïve adults and naïve pediatric patients 4 years of age and older is 60 Units/kg administered every other week as a 60-minute intravenous infusion. The dosage can be adjusted based on achievement and maintenance of each patient's therapeutic goals.

 Switching from Imiglucerase to VPRIV

Adults and pediatric patients 4 years of age and older currently being treated on a stable dosage of imiglucerase for type 1 Gaucher disease may be switched to VPRIV by starting treatment with VPRIV at the previous imiglucerase dosage two weeks after the last imiglucerase dose. VPRIV should be administered under the supervision of a healthcare professional as a 60-minute intravenous infusion. The dosage can be adjusted based on achievement and maintenance of each patient's therapeutic goals.

 Reconstitution of the VPRIV Lyophilized Powder

VPRIV is a lyophilized powder, which requires reconstitution and dilution, using sterile technique, prior to intravenous infusion. VPRIV should be prepared as follows:

(a)

Determine the number of vials to be reconstituted based on the individual patient's weight and the prescribed dose.

(b)

Inject 4.3 mL of Sterile Water for Injection, USP into a vial containing VPRIV lyophilized powder.

(c)

Mix gently. DO NOT SHAKE. The reconstituted VPRIV solution will have a 100 Units/mL concentration (400 Units VPRIV in 4 mL of solution).

(d)

If additional vials are needed, repeat steps (b) and (c).

(e)

Visually inspect the reconstituted VPRIV solution in the vials. The solution should be clear to slightly opalescent and colorless. Do not use if the solution is discolored or if foreign particulate matter is present.

(f)

With a single syringe, withdraw the calculated dose of drug from the appropriate number of vials. Using a separate syringe, withdraw air from a bag of 100 mL of 0.9% Sodium Chloride Injection suitable for intravenous administration. Then dilute the calculated dose of VPRIV directly into the 0.9% Sodium Chloride Injection. Mix gently. DO NOT SHAKE. Slight flocculation (described as white irregular shaped particles) may occasionally occur. Diluted solution with slight flocculation is acceptable for administration.

(g)

Because VPRIV contains no preservatives, use the reconstituted VPRIV solution and the diluted VPRIV solution immediately. If immediate use is not possible, the reconstituted VPRIV solution or the diluted VPRIV solution may be stored for up to 24 hours at 2ºC to 8ºC (36ºF to 46ºF). Do not freeze and protect from light. Complete the infusion within 24 hours of reconstitution of vials.

(h)

Vials are for one-time use and only for one patient. Discard any unused solution.

 Important Administration Instructions

         Administer the diluted VPRIV solution through an in-line low protein-binding 0.2 or 0.22 µm filter over 60 minutes. Do not infuse VPRIV with other products in the same infusion tubing because the compatibility of a VPRIV solution with other products has not been evaluated.        

 Premedication to Reduce Risk of Subsequent Hypersensitivity Reactions

Consider pre-treatment with antihistamines and/or corticosteroids in patients who exhibited symptoms of hypersensitivity associated with prior velaglucerase alfa product infusions. Appropriate medical support should be readily available when VPRIV is administered [see Warnings and Precautions (5.1)].

 Pregnancy

 Lactation

 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), Clinical Studies (14)]. The efficacy and safety of VPRIV has not been established in pediatric patients younger than 4 years of age.

 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.

 Hypersensitivity Reactions Including Anaphylaxis

Life-threatening hypersensitivity reactions, including anaphylaxis, have occurred in patients treated with enzyme replacement therapies, including VPRIV. VPRIV-treated patients have had these reactions occur in clinical studies and postmarketing experience [see Adverse Reactions (6.1) and Clinical studies (14)]. Hypersensitivity reactions were the most commonly observed adverse reactions in patients treated with VPRIV in clinical studies. Patients were not routinely pre-medicated prior to infusion of VPRIV during clinical studies. The most commonly observed symptoms of hypersensitivity reactions were: headache, dizziness, hypotension, hypertension, nausea, fatigue/asthenia, and pyrexia/body temperature increased. Generally the reactions were mild and, in treatment-naïve patients, onset occurred mostly during the first 6 months of treatment and tended to occur less frequently with time. Additional hypersensitivity reactions of chest discomfort, dyspnea, pruritus and vomiting have been reported in post-marketing experience.

Anaphylaxis has occurred during the early course of enzyme replacement therapy and after extended duration of therapy. Administration of VPRIV should be supervised by a healthcare provider knowledgeable in the management of hypersensitivity reactions including anaphylaxis. Initiate VPRIV in a healthcare setting with appropriate medical monitoring and support measures, including access to cardiopulmonary resuscitation equipment.

The management of hypersensitivity reactions should be based on the severity of the reaction, e.g., slowing the infusion rate, treatment with medications such as antihistamines, antipyretics and/or corticosteroids, and/or stopping and resuming treatment with increased infusion time. If a severe hypersensitivity reaction (e.g., anaphylaxis) occurs, discontinue VPRIV and immediately initiate appropriate medical treatment, including use of epinephrine.

In cases where patients have exhibited symptoms of hypersensitivity to velaglucerase alfa or excipients in the drug product or to other enzyme replacement therapy, pre-treatment with antihistamines and/or corticosteroids may prevent subsequent reactions. Inform patients of the symptoms of life-threatening hypersensitivity reactions, including anaphylaxis and to seek immediate medical care should symptoms occur.

 Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

The data described below reflect exposure of 94 patients with type 1 Gaucher disease who received VPRIV at doses ranging from 15 Units/kg to 60 Units/kg every other week in 5 clinical studies. Fifty-four (54) patients were naïve to enzyme replacement therapy (ERT) and received VPRIV for 9 months and 40 patients switched from imiglucerase to VPRIV treatment and received VPRIV for 12 months [see Clinical Studies (14)]. Patients were between 4 and 71 years old at time of first treatment with VPRIV, and included 46 male and 48 female patients.

The most serious adverse reactions in patients treated with VPRIV were hypersensitivity reactions [see Warnings and Precautions (5.1)].

The most commonly reported adverse reactions (occurring in ≥10% of patients) that were considered related to VPRIV are shown in Table 1. The most common adverse reactions were hypersensitivity reactions.

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.

 Immunogenicity

As with all therapeutic proteins, there is a potential for immunogenicity. The detection of antibody formation is highly dependent on the sensitivity and specificity of the assay. Additionally, the observed incidence of antibody (including neutralizing 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 in the studies described below with the incidence of antibodies in other studies or to other products may be misleading.

In clinical studies, 1 of 54 (2%) enzyme treatment-naïve patients treated with VPRIV developed IgG antibodies to VPRIV. One additional patient developed IgG antibodies to VPRIV during an extension study. In both patients, the IgG antibodies to VPRIV were determined to be neutralizing in an in vitro assay. The presence of IgG antibodies to VPRIV was not associated with hypersensitivity reactions. 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.

 Postmarketing Experience

The following adverse reactions have been identified during post-approval use of VPRIV. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Gastrointestinal disorders: vomiting (in some cases vomiting can be serious, requiring hospitalization and/or drug discontinuation)

 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.

 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.

 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 fertility study in male and female rats, velaglucerase alfa did not cause any significant adverse effect on male or female fertility parameters up to a maximum intravenous dose of 17 mg/kg (102 mg/m2, about 1.8 times the recommended human dose of 60 Units/kg based on the body surface area).

 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.

 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 2. 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.

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.

 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.

How Supplied

VPRIV (velaglucerase alfa) for injection is a sterile, preservative free, white to off-white lyophilized powder requiring reconstitution and further dilution prior to use. It is supplied in individually packaged single-dose 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. VPRIV is available as: 400 units/vial (NDC 54092-701-04).

Storage

Store VPRIV refrigerated at 2ºC to 8ºC (36ºF to 46ºF) in the original carton to protect from light. Do not freeze. Do not use VPRIV after the expiration date on the vial.