Biotechnology company Genzyme, of Cambridge, Mass., expects the U.S. Food and Drug Administration (FDA) to rule by June 17, 2010, on Genzyme's application to market its laboratory-developed enzyme Lumizyme (alglucosidase alfa) in the United States.
Lumizyme and its near-twin, Myozyme, replace the acid maltase enzyme deficient in people with Pompe disease (acid alpha-glucosidase deficiency or acid maltase deficiency).
Last December, the company also reopened enrollment in the Alglucosidase Alfa Temporary Access Program (ATAP), which provides access to treatment prior to commercial approval of Lumizyme for adults who are severely affected with Pompe disease. Children ages 17 and under have had continued and uninterrupted access to treatment with Myozyme.
Coming to terms: Myozyme and Lumizyme
In 2006, the FDA gave approval to Genzyme to market Myozyme. The drug was the first-ever treatment approved for Pompe disease in the United States, and has since been approved for use in Europe and more than 40 countries worldwide.
After FDA approval, growing demand for Myozyme led Genzyme to change its production processes. The company moved the bulk of its production from Allston, Mass., where the enzyme was made in 160-liter batches, to Geel, Belgium, where the drug could be produced in 4,000-liter tanks instead.
With the change in production came a new name for the familiar Myozyme: Lumizyme. The drug will continue to be called Myozyme outside the United States.
The name change was based on an FDA determination that the enzyme produced on the larger scale possessed slightly different biochemical characteristics than the original Myozyme, and should therefore be classified as a different drug.
Lumizyme should be available as soon as FDA approval is granted, Genzyme spokesperson Lori Gorski said.
No pricing structure has been announced yet, but the cost may be comparable to that of Myozyme, which historically has averaged around $300,000 per year. Dosage is based on a patient's weight, so the annual cost for children is less, and for heavier adults, higher.
Gorski said insurance and other third-party coverage likely will cover all or part of the cost for those to whom the drug is prescribed. Securing coverage may take time, however.
About Pompe disease
|In normal muscle fiber, subcellular components called lysosomes break down glycogen, or stored sugar. In Pompe disease, a deficiency of the acid maltase enzyme prevents the lysosomes from carrying out this function. Muscle fibers fill up with glycogen and can rupture. Over time, the working parts of the fiber can be damaged or destroyed.|
Pompe disease is a metabolic muscle disorder caused by the genetic deficiency of an enzyme called acid alpha-glucosidase that breaks down glycogen (stored sugar) inside muscle cells. Without the enzyme, glycogen accumulates and ruptures subcellular components.
In its severest form, where very little enzyme is produced, Pompe affects infants, weakening the heart and voluntary muscles. In those who produce greater amounts of the enzyme, the disease may manifest during childhood or adulthood, causing significant muscle weakness and respiratory problems.
Prior to the development of Myozyme, Pompe generally resulted in a shortened lifespan. Most infants born with the disease didn't survive past the age of 1 year.
In addition to contributing supplemental funds for Genzyme's Myozyme program, MDA provided support to Yuan-Tsong Chen at Duke University, whose work in the 1990s laid the foundation for development of Myozyme and, later, Lumizyme.
Meaning for people with Pompe disease
Genzyme currently has FDA approval to market Myozyme produced in 160-liter batches at Genzyme's Allston, Mass., facility. This product is reserved for patients in the United States ages 17 and younger.
With the company's decision to reopen enrollment in ATAP, adults severely affected with Pompe disease who meet eligibility requirements can seek treatment with Myozyme produced at a different U.S. facility. They should speak with their physician or contact Genzyme Medical Information at (800) 745-4447 for more information.