Lysosomal Storage Disorders: Orphan Drugs For Gaucher Disease
This is the fourth Blog Post in a series that will examine Lysosomal Storage Disorders (LSDs) in the rare disease and orphan drug space. This Blog Post reviews Orphan Drugs for the treatment of Gaucher Disease (GD). This week, the Lysosomal Disease Network’s 10th Annual WORLDSymposium is in San Diego, California.
GD is a LSD caused by a defect in a particular enzyme which breaks down fatty substance, or lipid, called glucocerebroside. As a result, glucocerebroside accumulates in cells and organs in the body, which prevents them from working correctly. There are three subtypes of GD:
• Type 1 is the most common form of GD with swelling, enlargement, and dysfunction of the spleen and liver; also, lung and bone problems
• Type 2 causes brain damage and death before two years of age
• Type 3 is progressive and affects the brain, with patients living often into their early teens and adulthood.
Enzyme Replacement Therapy (ERT) is a lifelong treatment (twice a month), throughout a patient’s life.for GD that involves the injection of an “intact version of the enzyme responsible for the normal breakdown of the lipid in healthy people.” The enzyme is not able to get into the brain because it can’t cross the blood-brain barrier, and thus is not effective in treating the neurological symptoms of GF Types 2 and 3.
Approved FDA Orphan Drugs
The following are the approved FDA orphan drugs for GD in approval date order:
|FDA Approval Date||Sponsor Company||Indication|
|Ceredase (Alglucerase)||04.05.91||Genzyme (Sanofi)||ERT for GD Type I|
|Cerezyme (Imiglucerase)||05.23.94||Genzyme (Sanofi)||ERT for GD Type I|
|Zavesca (Miglustat)||07.31.03||Actelion Pharmaceuticals||GD Type I where ERT is not a therapeutic option|
|Vpriv(Velaglucerase-Alfa)||02.26.10||Shire||GD Type I|
|Elelyso (Taliglucerase Alfa)||05.01.12||Pfizer||GD Type I|
Enzyme Replacement Therapy (ERT) Market
Genzyme pioneered ERT for Gaucher Disease with its orphan drug Cerezyme, which has enjoyed a period of market monopoly. Cerezyme is the Standard of Care (SOC) for GD. Competition in the form of two ERT drugs, Shire’s Vpriv and Pfizer/Protalix BioTherapeutics’ Elelyso, start to appear in 2010 as the new players in the GD marketplace. The GD ERT market is crowded with only a patient population worldwide of less than 10,000. The three drug competitors in the ERT GD market are :
|Sponsor Company||Approximate Cost/Patient/Year **|
|Cerezyme (Imiglucerase)||Genzyme (Sanofi)||$200,000||Injection|
|Elelyso (Taliglucerase Alfa)||Pfizer/Protalix BIoTherapeutics||$150,000||Injection|
** Cost From 2012 Article
Cerdelga: New Kid On the Block
If Genzyme’s orphan drug Cerdelga (Eliglustat) is to be a future entrant into the GD market, it must differentiate itself from the other three drug competitors. Cerdelga is an investigational oral therapy for adult patients with GD Type 1, while the ERT competitors are injections. Cerdelga is a novel ceramide analog given orally and is designed to partially inhibit the enzyme glucosylceramide synthase, resulting in the reduction in production of glucosylceramide. Cerdelga is a capsule to be taken twice daily as an “effective oral treatment alternative … and to provide a broader range of treatment options for GD patients and physicians.” Ceredelga will help to expand Genzyme’s GD franchise and will also increase the company’s market share further. Cerdelga is currently in review by both the European Medicines Agency (EMA) and the FDA. The FDA grants a 6-month Priority Review designation to its New Drug Application (NDA) in December 2013.
At the Lysosomal Disease Network’s 10th Annual WORLDSymposium, there are several presentations on Cerdelga, including interim results from the Phase III EDGE clinical trial and results from the Phase III ENCORE clinical trial.
Protalix Biotherapeutics Oral Entry Into The GD Market
Protalix BioTherapeutics announces today that the Phase I clinical trial data for oral Glucocerebrosidase (GCD), PRX-112, for GD is to be presented by Professor Ari Zimran at this week’s Lysosomal Disease Network’s 10th Annual WORLDSymposium.
“Oral GCD is the Company’s orally-delivered proprietary formulation of the plant cell-expressed enzyme, glucocerebrosidase (GCD), and contains the same active substance as taliglucerase alfa (ELELYSO™), the Company’s approved ERT.”
The oral GCD Phase I clinical trial is an exploratory, open-label study to evaluate the safety and pharmacokinetics of oral PRX-112 in 16 GD patients. Additionally, the drug’s pharmacokinetic profile and exploratory endpoints are evaluated.