Elelyso (taliglucerase alfa) is an enzyme replacement therapy developed by Protalix Biotherapeutics in collaboration with Pfizer.

Elelyso was approved by the U.S. Food and Drug Administration (FDA) in 2012 for the long-term treatment of adult patients with type 1 Gaucher disease and in 2015 for pediatric patients. It is the first plant cell-based recombinant therapeutic protein approved by the FDA or any other major regulatory authority.

How Elelyso works

Gaucher disease is caused by mutations in the gene that encodes for an enzyme called beta-glucocerebrosidase. This enzyme is responsible for breaking down a fatty compound called glucocerebroside. The mutation causes the enzyme not to function properly and as a result, glucocerebroside accumulates in the body, predominantly in the liver, spleen, and bone marrow, causing symptoms of the disease.

Individuals with Gaucher disease have an enlarged spleen and liver, low blood platelet counts (thrombocytopenia) and hemoglobin content (anemia), and skeletal issues including bone pain and brittle bones that are prone to fractures.

Enzyme replacement therapy is the gold-standard treatment for Gaucher disease. Recombinant human glucocerebrosidase is injected into the patient’s bloodstream regularly to supplement the faulty enzyme. Once taken up by the cells in the body, Elelyso breaks down the glucocerebroside that has built up. This normalizes the size of the spleen and liver, improves blood hemoglobin content and platelet counts, and improves other biomarkers related to Gaucher disease.

Elelyso in clinical trials

A Phase 3, multicenter, open-label clinical trial (NCT00712348) assessed the safety and efficacy of switching to Elelyso in 26 adult and five pediatric patients with Gaucher disease treated with Cerezyme (imiglucerase), another recombinant human beta-glucocerebrosidase, for at least two years. Patients with stable disease were given Elelyso treatment using the same dose and regimen of administration as Cerezyme. Results showed that disease parameters (spleen and liver volumes, hemoglobin concentration, platelet count, and biomarker levels) remained stable through the nine months of treatment. All treatment-related adverse events were mild or moderate in severity and transient.

An extension of the above-mentioned study (NCT00705939) was performed in 18 patients for up to 36 months. The results showed stabilization of disease parameters and no significant adverse events.

Two Phase 3 clinical trials assessed the pharmacokinetics (movement in the body) of Elelyso in adult (NCT00376168) and pediatric patients (NCT01411228) with Gaucher disease. Patients received two doses of treatment (30 units per kg and 60 units per kg) every two weeks for 38 weeks. The results showed that in both adult and pediatric patients, the maximum plasma concentration was higher after the 60 units/kg dose than the 30 units/kg dose and there was no change in the pharmacokinetic parameters of Taliglucerase alfa over time from day 1 to week 38.

A multicenter, randomized, double-blind, Phase 4 clinical trial (NCT01132690) assessed the efficacy and safety of Elelyso in 11 pediatric patients with Gaucher disease who were again given two doses of Elelyso (30 units per kg in six patients or 60 units per kg in five patients) every other week for one year. The results showed that mean liver and spleen volumes decreased considerably, and hemoglobin levels and platelet counts increased significantly. Only mild adverse events were reported, all of which were transient and unrelated to treatment.

Another multicenter, open-label Phase 4 clinical trial (NCT03021941) is currently recruiting participants in Virginia to evaluate the pharmacokinetics, pharmacodynamics (effect on the body), and safety of Elelyso in children up to age 12 with type 1 Gaucher disease. The trial is expected to be completed in June 2020.


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