The company expects to make Xenpozyme available in the coming weeks in the U.S at a list price of $7,142 per vial.
Acid Sphingomyelinase Disease (ASD) is a rare genetic disease that occurs when the body does not have the necessary enzyme available to break down sphingomyelin, which is a complex lipid. Consequently, sphingomyelin accumulates in different parts of the body such as the liver, lungs, spleen and brain. Patients who suffer from ASD typically have enlarged abdomens and difficulty eating. Moreover, they also have trouble vomitting and are prone to falls. Treatment with Xenpozyme is expected to improve lung function and reduce liver and spleen size.
There are around 120 patients who suffer from ASD in the United States and most of them are children, who would otherwise not survive over the age of 3. Patients who typically reach adulthood often die prematurely from respiratory failure.
The hydraulic lysosomal enzyme replacement therapy, Xenpozyme, helps reduce sphingomyelin buildup in the body and proved to be effective in a placebo-controlled study of 31 patients. Since the study measured treatment benefits that were discovered during the duration of the study and also had the placebo comparator, FDA not only approved the therapy but also awarded the sponsor a rare pediatric disease priority review voucher, to incentivise the development of new drugs that prevent and treat rare diseases in children.
“This long awaited medical advancement will be much appreciated by patients suffering for ASD, them, their families and their doctors all will be looking forward to it,” said Christine Nguyen, M.D., deputy director of the Office of Rare Diseases, Pediatrics, Urologic and Reproductive Medicine in the FDA’s Center for Drug Evaluation and Research. “The obstacles we will come across in developing treatments for a disease as distinctive as this will be many but the unparalleled need to develop treatment options for this disease cannot be overlooked.”
The approval for this drug in the United States was preceded by that of authorities in Japan and Europe. The former of which has approved it to treat Niemann-Pick, a rare genetic disease that prevents the body from breaking down fats and leads to premature death. The approval was previously expected to come at the beginning of October, a time that was set after a 3 month extension.
However, it is to be noted that the drug is only approved for the non-central nervous system (non-CNS) manifestations of the disease, according to representatives of Sanofi, the drug is not expected to cross the blood brain barrier or modulate CNS manifestations of ASMD nor has it been studied in patients with that (type A) form of the disease.
The company expects to make Xenpozyme available in the coming weeks in the U.S at a list price of $7,142 per vial and the drug has to be administered every two weeks.
This intravenously infused treatment will be made available to both children and adults in the country.
Xenpozyme has already received fast track, breakthrough therapy, and priority review designations. Additionally, It has also received orphan drug designation, which provides incentives to assist and encourage the development of drugs for rare diseases.
