Vimizim Drug Information

(elosulfase alfa) is indicated for patients with Mucopolysaccharidosis type IVA (MPS IVA; Morquio A syndrome). VIMIZIM is a hydrolytic lysosomal glycosaminoglycan (GAG)-specific enzyme indicated for patients with Mucopolysaccharidosis type IVA (MPS IVA; Morquio A syndrome).

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. A 24-week, randomized, double-blind, placebo-controlled clinical trial of VIMIZIM was conducted in 176 patients with MPS IVA, ages 5 to 57 years old. Approximately half of the patients (49%) were male.

Of the 176 patients, 65% were White, 23% Asian, 3% Black, and 10% Other race. The majority of patients (78%) were non-Hispanic. Patients were randomized to three treatment groups: VIMIZIM 2 mg/kg once per week (n=58), VIMIZIM 2 mg/kg once every other week (n=59), or placebo (n=59). All patients were treated with antihistamines prior to each infusion.

Table 3 summarizes the most common adverse reactions that occurred in the placebo-controlled trial with an incidence of ≥ 10% in patients treated with VIMIZIM 2 mg/kg once per week and with a higher incidence than in the placebo-treated patients. Table 3: Adverse Reactions That Occurred in the Placebo-Controlled Trial in At Least 10% of Patients in the VIMIZIM 2 mg/kg Once Per Week Group and with a Higher Incidence than in the Placebo Group Adverse Reaction VIMIZIM 2 mg/kg once per week Placebo N= 58 n (%) N= 59 n (%) Pyrexia 19 (33%) 8 (14%) Vomiting 18 (31%) 4 (7%) Headache 15 (26%) 9 (15%) Nausea 14 (24%) 4 (7%) Abdominal pain 12 (21%) 1 (2%) Chills 6 (10%) 1 (2%) Fatigue 6 (10%) 2 (3%) Extension Trial An open-label extension trial was conducted in 173 patients who completed the placebo-controlled trial . No new adverse reactions were reported.

Immunogenicity As with all therapeutic proteins, including

VIMIZIM, there is 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 in other studies or to other elosulfase alfa products may be misleading. All patients treated with VIMIZIM 2 mg/kg once per week in the placebo-controlled trial developed anti-drug antibodies by Week 4. Anti-drug antibody titers were sustained or increased for the duration of VIMIZIM treatment. Because all patients developed anti-drug antibodies, associations between antibody titers and reductions in treatment effect or the occurrence of anaphylaxis or other hypersensitivity reactions could not be determined.

All patients treated with VIMIZIM 2 mg/kg once per week tested positive for neutralizing antibodies capable of inhibiting the drug from binding to the mannose-6-phosphate receptor at least once during the trial. Binding to this receptor is required for VIMIZIM to be taken into cells where it is active. Neutralizing antibody titers were not determined in the patients.

Therefore, the possibility of an association between neutralizing antibody titer and treatment effect cannot be assessed.

Pregnancy Risk Summary Available data from published case reports, a registry with a pregnancy sub-study and pharmacovigilance reports with VIMIZIM use during pregnancy have not identified a drug-associated risk of major birth defects, miscarriage, or adverse maternal or fetal outcomes. Limitations of the available data include a small number of exposed cases and missing data. In animal reproduction studies, no effects on embryo-fetal development were observed in rats given daily administration of elosulfase alfa up to 33 times the human steady-state AUC (area under the concentration-time curve) at the recommended human weekly dose pre-mating and through the period of organogenesis.

No effects on embryo-fetal development were observed in rabbits given daily administration of elosulfase alfa at doses up to 8 times the human steady-state AUC at the recommended weekly dose during organogenesis, which produced maternal toxicity. A dose-dependent increase in stillbirths was observed when elosulfase alfa was administered daily in rats during organogenesis through lactation at doses 5 times the human steady-state AUC at the recommended human weekly dose. An increase in pup mortality was observed at doses producing maternal toxicity.

The background risk of major birth defects and miscarriage for the indicated population is unknown. All pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively.

Clinical Considerations Disease-associated maternal and embryo/fetal risk Pregnancy can exacerbate preexisting clinical manifestations of MPS and lead to adverse outcomes for both mother and fetus. Data Animal Data All reproductive studies with rats included pre-treatment with diphenhydramine to prevent or minimize hypersensitivity reactions. The effects of elosulfase alfa were evaluated based on comparison to a control group treated with diphenhydramine alone.

Daily intravenous administration of up to 20 mg/kg elosulfase alfa in rats (33 times the human steady-state AUC at the recommended weekly dose of 2 mg/kg) during a 15-day pre-mating period, mating, and the period of organogenesis, produced no maternal toxicity or effects on embryo-fetal development. Daily intravenous administration of up to 10 mg/kg in rabbits (8 times the human steady-state AUC at the recommended weekly dose) during the period of organogenesis had no effects on embryo-fetal development. However, maternal toxicity (gross changes in liver) was observed in rabbits given doses of 1 mg/kg/day and higher (0.1 times the human steady-state AUC at the recommended weekly dose). Elosulfase alfa produced an increase in the percentage of stillbirths when administered daily to rats at intravenous doses of 6 mg/kg and higher (5 times the human steady-state AUC at the recommended weekly dose) during the period of organogenesis through lactation.

Daily intravenous administration of 20 mg/kg (33 times the human steady-state AUC at the recommended weekly dose) produced maternal toxicity and an increase in mortality of offspring during the lactation period. This study lacked a full evaluation of neurodevelopmental milestones; however, no effects of elosulfase alfa were noted in tests for learning and memory.

Pediatric Use Safety and effectiveness of VIMIZIM have been established in pediatric patients 5 years of age and older. Use of VIMIZIM in patients 5 years of age and older is supported by an adequate and well-controlled trial in pediatric and adult patients. Clinical trials with VIMIZIM were conducted in 176 patients (median age 12 years, range 5 to 57 years old) with the majority of patients in the pediatric age group (53% aged 5 to 11 years, 27% aged 12 to 17 years) . Safety and effectiveness in pediatric patients below 5 years of age have not been established.