Successful desensitization to imiglucerase of an adult patient diagnosed with type I Gaucher disease.

Gaucher disease is the most common lysosomal storage disorder, and enzyme replacement therapy, such as administration of imiglucerase, is the standard therapy. Anaphylaxis to imiglucerase is rarely reported. Here, we report a 26-year-old female who was diagnosed with type 1 Gaucher disease and referred to our Allergy Outpatient Clinic because of an anaphylactic reaction due to imiglucerase enzyme therapy. A desensitization protocol was administered with two different dilutions with an increasing rate of administration delivered in 10 consecutive steps by intravenous infusion in an intensive care setting. No reactions occurred during the procedure, and the total final dose of 2,000 U was successfully administered. To our knowledge, this is the first adult case with successful desensitization to imiglucerase. Desensitization protocols to drugs in chronic disease patients for whom no alternative therapies are available can be lifesaving.

Velaglucerase alfa for the management of type 1 Gaucher disease.

BACKGROUND: Gaucher disease (GD) is the most common lysosomal storage disease, (frequency of 1:40,000 to 1:60,000). Ninety-Five percent of patients have type 1 (nonneuropathic type). Symptomatic patients with type 1 GD are treated with enzyme replacement therapy (ERT) to improve disease-induced effects on hemoglobin, platelets, and liver and spleen volume. Currently, several ERTs are available. OBJECTIVE: The goal of this article was to review the pharmacology, efficacy, and safety data available for the use of a recently approved ERT, velaglucerase alfa, for the treatment of type 1 GD in symptomatic pediatric and adult patients. METHODS: Serial searches of MEDLINE, EMBASE, and Cochrane databases for English-language, peer-reviewed, clinical data (using the search term velaglucerase alfa) were completed, with the final search in November 2011. All identified, peer-reviewed published human data were used for this review. Due to minimal peer-reviewed published data, those data reported via clinical trial registries or in the form of published abstracts were included. The manufacturer was contacted and given the opportunity to submit supplemental data for consideration of inclusion by the author. RESULTS: Velaglucerase alfa is produced through gene activation technology and is identical to wild-type enzyme. As with other ERTs for type 1 GD, velaglucerase alfa targets accumulated glucocerebroside primarily within the lysosome of the macrophages in the affected organs and systems. When administered at doses of 60 U/kg intravenously, velaglucerase alfa follows linear pharmacokinetics and is rapidly eliminated, with a mean (SD) residence time or time for 63% of the dose to be cleared from systemic circulation of 14 (4) minutes. Four trials and early access program data reporting efficacy were identified for this review: 5 peer-reviewed publications, 3 clinical trial registry reports, and 1 abstract-only publication. Phase I/II data with an extension phase (n = 12) showed significant improvements (all, P < 0.004) in hemoglobin concentrations (21.7%), platelet counts (157.8%), and hepatic (-42.8%) and spleen (-79.3%) volumes at 48 months. Bone mineral density data reported out to 69 months for this extension population noted significant improvements in z score slope for both lumbar spine (0.14 z score unit per year; P < 0.01) and femoral head (0.08 z score unit per year; P < 0.01). Benchmarking of 7 patients with complete clinical datasets at 57 months identified achievement and maintenance of therapeutic goals set by the International Collaborative Gaucher Group for anemia, platelet counts, hepatosplenomegaly, and bone mineral density. Thirty-eight patients enrolled in an open-label, therapy-switch trial who received velaglucerase alfa at doses consistent with current doses of imiglucerase maintained hemoglobin (-0.101 g/dL [95% CI, -0.272 to 0.07]) and platelet counts (7.04% [95% CI, 0.54% to 13.53%]) at 53 weeks after therapy change. Phase III data evaluating 2 dosing regimens of velaglucerase alfa 60 and 45 U/kg intravenously every other week reported significant improvements in most measured clinical parameters at 12 months: hemoglobin concentrations (60 U/kg, 2.429 [0.324] g/dL [P < 0.0001]; 45 U/kg, 2.438 g/dL [95% CI, 1.488 to 3.389]), platelet counts (60 U/kg, 50.88 × 10(9)/L [95% CI, 23.97 to 77.78]; 45 U/kg, 40.92 × 10(9)/L [95% CI, 11.2 to 70.64]), spleen volumes (60 U/kg, -1.92% of body weight [95% CI, -3.04 to -0.79]; 45 U/kg, -1.87% of body weight [95% CI, -3.17 to -0.57]), and hepatic volumes (60 U/kg, -0.84% of body weight [95% CI, -1.58 to -0.11]). A subanalysis of the pediatric population showed clinical improvements at 12 months in both dosing groups: hemoglobin concentrations (60 U/kg, 1.74 g/dL [95% CI, 0.72 to 2.78]; 45 U/kg, 2.77 g/dL [95% CI, -0.99 to 6.53]), platelet counts (60 U/kg, 49.9 × 10(9)/L [95% CI, -32.1 to 131.9]; 45 U/kg, 60.3 × 10(9)/L [95% CI, -103.1 to 223.7]), spleen volumes (60 U/kg, -2.1 cm(3) [95% CI, -5.3 to 1.1]; 45 U/kg, -0.7 cm(3) [95% CI, -2.6 to 1.2]), and hepatic volumes (60 U/kg, -0.7 cm(3) [95% CI, -1.4 to 0.0]; 45 U/kg, -0.3 cm(3) [95% CI, -1.7 to 1.1]). Data comparing velaglucerase alfa with imiglucerase identified similar changes in hemoglobin concentrations at 1.624 g/dL and 1.488 g/dL, respectively, after 9 months of therapy. Safety was reported in 3 identified studies and in data reported from the early access program: 3 peer-reviewed publications, 3 studies reported in clinical trial registries, and 1 abstract publication. Patients experienced a minimal number of adverse effects, and most reactions were mild to moderate in severity; 1 patient developed an anaphylactoid reaction and was discontinued from the trial. Antibody formation has been described with velaglucerase alfa but when compared with that of imiglucerase, seroconversion is less frequent (1% and 23%, respectively). Dosing regimens, from 30 to 60 U/kg intravenously every other week, have been assessed. Currently, the manufacturer recommends 60 U/kg intravenously every other week; however, further studies and evaluation of current study dosing regimens are needed to determine if there is a lower effective dose. CONCLUSIONS: Although a minimal amount of data are available for this relatively new biological agent, velaglucerase alfa reportedly is effective in the achievement and maintenance of therapeutic goals in type 1 GD in both treatment-naive and patients previously treated with imiglucerase. This agent has been reasonably well tolerated in clinical trials and may be considered for use in symptomatic patients with type 1 GD.

A plant-derived recombinant human glucocerebrosidase enzyme--a preclinical and phase I investigation.

UNLABELLED: Gaucher disease is a progressive lysosomal storage disorder caused by the deficiency of glucocerebrosidase leading to the dysfunction in multiple organ systems. Intravenous enzyme replacement is the accepted standard of treatment. In the current report, we evaluate the safety and pharmacokinetics of a novel human recombinant glucocerebrosidase enzyme expressed in transformed plant cells (prGCD), administered to primates and human subjects. Short term (28 days) and long term (9 months) repeated injections with a standard dose of 60 Units/kg and a high dose of 300 Units/kg were administered to monkeys (n = 4/sex/dose). Neither clinical drug-related adverse effects nor neutralizing antibodies were detected in the animals. In a phase I clinical trial, six healthy volunteers were treated by intravenous infusions with escalating single doses of prGCD. Doses of up to 60 Units/kg were administered at weekly intervals. prGCD infusions were very well tolerated. Anti-prGCD antibodies were not detected. The pharmacokinetic profile of the prGCD revealed a prolonged half-life compared to imiglucerase, the commercial enzyme that is manufactured in a costly mammalian cell system. These studies demonstrate the safety and lack of immunogenicity of prGCD. Following these encouraging results, a pivotal phase III clinical trial for prGCD was FDA approved and is currently ongoing. TRIAL REGISTRATION: ClinicalTrials.gov NCT00258778.

[Clinical study of the French cohort of Gaucher disease patients]. / Etude clinique de la cohorte française de patients atteints de la maladie de Gaucher.

A census is currently being carried out of the French cohort of Gaucher disease patients. This article describes its preliminary results, obtained by analysing the records of 101 patients for whom clinical and laboratory data were accessible while they were receiving enzyme therapy. At the time of diagnosis, all patients presented with splenomegaly, 70% had asthenia and one in three was already affected by major bone damage. After 1 year of enzyme therapy, splenomegaly had diminished by half and the different scores (asthenia, bone pain and abdominal pain, etc.) had markedly improved, as had the biochemical markers. As for the 6 patients affected by type 3 Gaucher disease and treated with enzyme therapy after the onset of neurological signs, a stabilisation or even some improvement of the disease was observed. In-depth study of the French cohort should make it possible to formulate consensus recommendations for the future, based on well-established data.

Miglustat: new drug. In type 1 Gaucher's disease : a slight benefit after imiglucerase therapy.

(1) For patients with type 1 Gaucher's disease the standard treatment is imiglucerase enzyme replacement therapy, provided in fortnightly intravenous infusions. (2) Miglustat inhibits the synthesis of glucosyl-ceramide, the cerebroside that accumulates in Gaucher's disease. Miglustat is now licensed for oral therapy in patients with mild to moderate type 1 Gaucher's disease and who cannot take imiglucerase, regardless of the reason. (3) The evaluation data we managed to gather (see literature search) includes data from three trials involving a total of 82 patients. One of these trials compared miglustat with ongoing imiglucerase therapy. Miglustat slightly reduced the size of the liver and spleen, and slightly increased the haemoglobin level and platelet count after 18 months. The impact of these effects is unknown, especially on bone disorders. In patients with previous response to imiglucerase, miglustat has not been found to maintain clinical effects in the longer term. (4) Miglustat has many adverse effects, some of which occur very frequently, such as diarrhea (86%), weight loss (64%), peripheral neuropathies (19%), tremor (29%), and cognitive disorders. Animal studies suggest a risk of reproductive toxicity. (5) In practice, miglustat therapy offers minimal benefits for the few patients who cannot use imiglucerase. The potential advantages of miglustat therapy relative to purely symptomatic treatment must be carefully weighed in individual patients.