Velmanase alfa 10mg powder for solution for infusion vials

INTRODUCTION: This phase III, double-blind, randomised, placebo-controlled trial (and extension phase) was designed to assess the efficacy and safety of velmanase alfa (VA) in alpha-mannosidosis (AM) patients. METHODS: Twenty-five patients were randomised to weekly 1 mg/kg VA or placebo for 52 weeks. At study conclusion, placebo patients switched to VA; 23 patients continued receiving VA in compassionate-use/follow-on studies and were evaluated in the extension phase [last observation (LO)]. Co-primary endpoints were changes in serum oligosaccharide (S-oligo) and in the 3-min stair-climb test (3MSCT). RESULTS: Mean relative change in S-oligo in the VA arm was -77.6% [95% confidence interval (CI) -81.6 to -72.8] at week 52 and -62.9% (95% CI -85.8 to -40.0) at LO; mean relative change in the placebo arm was -24.1% (95% CI -40.3 to -3.6) at week 52 and -55.7% (95% CI -76.4 to -34.9) at LO after switch to active treatment. Mean relative change in 3MSCT at week 52 was -1.1% (95% CI -9.0 to 7.6) and - % (95% CI -13.4 to 6.5) for VA and placebo, respectively. At LO, the mean relative change was 3.9% (95% CI -5.5 to 13.2) in the VA arm and 9.0% (95% CI -10.3 to 28.3) in placebo patients after switch to active treatment. Similar improvement pattern was observed in secondary parameters. A post hoc analysis investigated whether some factors at baseline could account for treatment outcome; none of those factors were predictive of the response to VA, besides age. CONCLUSIONS: These findings support the utility of VA for the treatment of AM, with more evident benefit over time and when treatment is started in the paediatric age.

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Alpha-mannosidosis (AM) is a rare, autosomal recessive, lysosomal storage disorder caused by alpha-mannosidase deficiency that leads to the accumulation of mannose-rich oligosaccharides. AM symptoms and severity vary among individuals; consequently, AM is often not diagnosed until late childhood. Velmanase alfa (VA), a recombinant human lysosomal alpha-mannosidase product, is the first enzyme replacement therapy indicated to treat non-neurological symptoms of AM in Europe. Previous studies suggested that early VA treatment in children may produce greater clinical benefit over the disease course than starting treatment in adolescents or adults; however, long-term studies in children are limited, and very few studies include children under 6 years of age. The present phase 2, multicenter, open-label study evaluated the safety and efficacy of long-term VA treatment in children under 6 years of age with AM. Five children (three males) received VA weekly for ≥24 months, and all children completed the study. Four children experienced adverse drug reactions (16 events) and two experienced infusion-related reactions (12 events). Most (99.5%) adverse events were mild or moderate, and none caused study discontinuation. Four children developed antidrug antibodies (three were neutralizing). After VA treatment, all children improved in one or more efficacy assessments of serum oligosaccharide concentrations (decreases), hearing, immunological profile, and quality of life, suggesting a beneficial effect of early treatment. Although the small study size limits conclusions, these results suggest that long-term VA treatment has an acceptable safety profile, is well tolerated, and may provide potential benefits to patients with AM under 6 years of age.

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Enzyme replacement therapy (ERT) using velmanase alfa previously showed promising efficacy and safety outcomes for up to 4 years of therapy in patients with alpha-mannosidosis. This pooled analysis from two multicenter, open-label phase IIIb extension trials rhLAMAN-07 (N = 13; NCT01908712) and rhLAMAN-09 (N = 8; NCT01908725) evaluated the long-term effects of velmanase alfa. Sixteen patients who previously completed phase I-III rhLAMAN-02/-03/-04/-05/-08 trials and five ERT-naïve patients were enrolled. Patients received 1 mg/kg velmanase alfa once weekly. Endpoints included changes from treatment baseline (before initial dose of velmanase alfa in any trial) in serum oligosaccharides, 6-minute walk test (6MWT), 3-minute stair climb test (3MSCT), pulmonary function (forced vital capacity [FVC], % predicted), serum immunoglobulin G (IgG) levels, and adverse events. The overall cohort comprised 21 patients, divided by age at treatment baseline into pediatric (n = 14) and adult subgroups (n = 7). Distance walked according to 6MWT increased or stabilized in pediatric patients, while in adults either stabilization or slight decline was observed. Similarly, pediatric patients performed better in the 3MSCT. Changes in FVC, % predicted, were comparable in both subgroups up to ~6 years of observation, diverging thereafter. Overall, sustained serum oligosaccharide clearance and serum IgG level increase was observed upon treatment initiation and persisted until last common observation. Velmanase alfa treatment was generally well tolerated, with the majority of reported adverse events being of mild-to-moderate intensity. With follow-up of up to 12 years, long-term efficacy and safety outcomes indicate continued benefits of velmanase alfa in patients with alpha-mannosidosis.

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INTRODUCTION: Long-term outcome data provide important insights into the clinical utility of enzyme replacement therapies. Such data are presented for velmanase alfa in the treatment of alpha-mannosidosis (AM). METHODS: Patient data (n = 33; 14 adults, 19 paediatric) from the clinical development programme for velmanase alfa were integrated in this prospectively-designed analysis of long-term efficacy and safety. Patients who participated in the phase I/II or phase III trials and were continuing to receive treatment after completion of the trials were invited to participate in a comprehensive evaluation visit to assess long-term outcomes. Primary endpoints were changes in serum oligosaccharide and the 3-minute stair climb test (3MSCT). RESULTS: Mean (SD) treatment exposure was 29.3 (15.2) months. Serum oligosaccharide levels were significantly reduced in the overall population at 12 months (mean change: -72.7%, P < 0.001) and remained statistically significant at last observation (-62.8%, P < 0.001). A mean improvement of +9.3% in 3MSCT was observed at 12 months (P = 0.013), which also remained statistically significant at last observation (+13.8%, P = 0.004), with a more pronounced improvement detected in the paediatric subgroup. No treatment-emergent adverse events were reported leading to permanent treatment discontinuation. CONCLUSIONS: Patients treated with velmanase alfa experienced improvements in biochemical and functional measures that were maintained for up to 4 years. Long term follow-up is important and further supports the use of velmanase alfa as an effective and well-tolerated treatment for AM. Based on the currently available data set, no baseline characteristic can be predictive of treatment outcome. Early treatment during paediatric age showed better outcome in functional endpoints.

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Alpha-mannosidosis is an inherited rare disorder of mannose-containing oligosaccharides metabolism that is currently treated by enzyme replacement therapy (ERT), bone marrow transplantation (BMT), or supportive therapy (ST). However, the relative cost-effectiveness of these treatment options is yet unknown. Our study aimed to compare the cost-effectiveness of the treatment options for mild to moderate alpha-mannosidosis. The study is based on a modeling approach using a Discrete-Event Simulation model to generate and simulate the course of the disease under the influence of each of the treatment options: ERT, BMT, and ST. The model had a lifetime horizon and was made from the perspective of the Serbian Health Insurance Fund. Currently, available causal therapy of mild to moderate alpha-mannosidosis with velmanase alpha enzyme replacement is not cost-effective compared with supportive therapy (ICER = 941,587,152 RSD) or bone marrow transplantation (ICER = −398,412,755 RSD). Bone marrow transplantation can be cost-effective compared to supportive therapy (ICER = 6,032,689 RSD), but only if the willingness-to-pay threshold is increased to 9 gross domestic products (GDP) per capita per QALY gained. According to the current threshold, velmanase-alfa is not cost-effective compared to BMT or ST. To make alfa-mannosidosis therapy widely accessible to patients, criteria for assessing the cost-effectiveness of orphan drugs must include not only the absolute value of ICER but other aspects like equity weightings of QALYs, risk-sharing, reimbursement of severe forms of a disease only, or availability of dedicated funding.

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Abstract Alpha‐mannosidosis (AM), an autosomal recessive disorder caused by pathogenic biallelic variants in the MAN2B1 gene, leads to lysosomal alpha‐mannosidase deficiency and accumulation of mannose‐rich oligosaccharides. Velmanase alfa (VA), a recombinant human lysosomal alpha‐mannosidase, is the first enzyme replacement therapy for non‐neurological symptoms of AM. Previously, a potential relationship was identified between three MAN2B1 genotype/subcellular localization subgroups (G1, G2, and G3) and AM disease severity. In VA‐treated patients with AM, it is unknown if a relationship exists between MAN2B1 genotype/subcellular localization subgroups, antidrug antibodies (ADAs), and infusion‐related reactions (IRRs). This pooled analysis evaluated data from 33 VA‐treated patients with AM to investigate this relationship. Overall, 10 patients were positive for ADAs, 4 of whom had treatment‐emergent ADAs (G1: 3/7 [43%]; G2: 1/17 [6%]; G3: 0/9). Treatment‐emergent ADA‐positive patients with relatively high titers ( n = 2; G1: 1012 U/ml and G2: 440 U/ml) experienced mild/moderate IRRs that were well‐managed; patients with lower titers ( n = 2) experienced no IRRs. Overall, changes from baseline in serum oligosaccharides and immunoglobulin G levels did not vary between ADA‐positive and ADA‐negative patients, suggesting a similar effect of VA treatment regardless of ADA status in most patients. Clinical outcomes (3MSCT and 6MWT) were also similar in most patients regardless of ADA status. While further studies are needed, these data suggest a relationship between MAN2B1 genotype/subcellular localization subgroups and ADA development, with G1 and G2 subgroups more likely to develop ADAs and IRRs. Regardless, this study suggests that ADAs have limited effect on the clinical impact of VA in most patients with AM.

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Alpha-mannosidosis is an ultra-rare lysosomal disease that is caused by variants of the MAN2B1 gene on chromosome 19p13. These variants result in faulty or absent alpha-mannosidase in lysosomes, which leads to intracellular accumulation of mannose-containing oligosaccharides. Diagnosis of alpha-mannosidosis is often delayed, in part because of the rarity of the disease, its gradual onset and heterogeneity of presentation, but also because of the similarity of many signs and symptoms of the disease to those of other lysosomal diseases. Treatment of alpha-mannosidosis was previously limited to hematopoietic stem cell transplantation, but outcomes are variable and not all patients are eligible or have a suitable donor. Recently, an enzyme replacement therapy, recombinant human alpha-mannosidase (velmanase alfa), was approved for the treatment of non-neurological manifestations in adult and pediatric patients with alpha-mannosidosis. Treatment with velmanase alfa reduces serum levels of oligosaccharides, increases levels of immunoglobulin G, and improves patients' functional capacity and quality of life, although it is not effective for the neurologic phenotype because it does not cross the blood-brain barrier. Since the effects of velmanase alfa are more marked in children than adults, early diagnosis to allow early initiation of treatment has become more important. To support this, patient, parent/caregiver, and clinician awareness and education is imperative. A number of approaches can be taken to meet this goal, such as the development of disease registries, validated diagnostic algorithms, and screening tools, improved under-/post-graduate clinician education, easily accessible and reliable information for patients/families (such as that made available on the internet), and the formation of patient advocacy groups. Such approaches may raise awareness of alpha-mannosidosis, reduce the diagnostic delay and thus improve the lives of those affected.

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Alpha-mannosidosis (AM) is an autosomal recessive lysosomal storage disorder caused by reduced activity of the enzyme alpha-mannosidase. The disease is characterized by immunodeficiency, facial and skeletal abnormalities, impaired hearing, and intellectual disability. The clinical subtype of AM shows considerable variability in an individual, and at present, at least three clinical subtypes are suggested. Diagnosis is made by identification of deficiency of α-mannosidase activity in nucleated cells, like fibroblasts. The children are often born apparently normal as the disease is insidiously progressive, hence making early diagnosis essential. Along with supportive care, long-term therapeutic options include hematopoietic stem cell transplant, bone marrow transplantation, and enzyme replacement therapy. The possible benefits of these procedures must be weighed against the overall risk of procedure-related morbidity and mortality. Velmanase alfa is the first human recombinant form of alpha-mannosidase licensed and available for long-term enzyme replacement therapy. It is approved for treating non-neurologic manifestations of mild to moderate AM. The results obtained from different clinical trials provide evidence of the positive clinical effect of the recombinant enzyme on patients with AM. Different routes of diagnosis and unspecific initial symptoms of the disease lead to a delay in the initiation of treatment, resulting in accumulative morbidity. Thus, there is a dire necessity to create more awareness. Furthermore, additional multiple large-scale trials are needed to evaluate the long-term safety and efficacy of velmanase alfa.

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Alpha-mannosidosis is an ultra-rare monogenic disorder resulting from a deficiency in the lysosomal enzyme alpha-mannosidase, with a prevalence estimated to be as low as 1:1,000,000 live births. The resulting accumulation of mannose-rich oligosaccharides in all tissues leads to a very heterogeneous disorder with a continuum of clinical manifestations with no distinctive phenotypes. Long-term enzyme replacement therapy (ERT) with velmanase alfa is approved in Europe for the treatment of non-neurological manifestations in patients with mild to moderate alpha-mannosidosis. The clinical heterogeneity and rarity of the disease limit the sensitivity of single parameters to detect clinically relevant treatment effects. Thus, we propose a novel multiple variable responder analysis to evaluate the efficacy of ERT for alpha-mannosidosis and present efficacy analyses for velmanase alfa using this method. Global treatment response to velmanase alfa (defined by response to ≥2 domains comprising pharmacodynamic, functional, and quality of life outcomes) was applied post hoc to data from the pivotal placebo-controlled rhLAMAN-05 study and to the longer-term integrated data from all patients in the clinical development program (rhLAMAN-10). After 12 months of treatment, a global treatment response was achieved by 87% of patients receiving velmanase alfa (n = 15) compared with 30% of patients receiving placebo (n = 10). Longer-term data from all patients in the clinical program (n = 33) showed 88% of patients were global responders, including all (100%) pediatric patients (n = 19) and the majority (71%) of adult patients (n = 14). The responder analysis model demonstrates a clinically meaningful treatment effect with velmanase alfa and supports the early initiation and continued benefit of longer-term treatment of all patients with alpha-mannosidosis with this ERT.

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