When a condition becomes unaffordable to treat Alexander disease: The illness that affects only 0.0001% of the population and has no cure but instead a $1,140,000 yearly treatment.
Alexander disease is an extremely rare, progressive genetic disorder that occurs within the central nervous system and damages the protective myelin sheath responsible for covering the nerve fibers. Therefore, it belongs to a group of conditions known as leukodystrophies and is considered so unusual on a global scale that it affects one in every one to three million people worldwide. The causes for Alexander disease vary depending on each individual’s personal story. There are three root causes that lead to the development of Alexander disease, them being gene mutation, inheritance, and Leukodystrophy. Firstly there is gene mutation, a mutation in the GFAP (glial fibrillary acidic protein) gene on chromosome 17q21 which generates supportive filaments in the nervous system. Then there is inheritance, which usually occurs in a random pattern as a new mutation, yet it could also be inherited in an autosomal dominant pattern. Finally, the most common root cause is Leukodystrophy where it occurs within the central nervous system and destroys the protective myelin sheath responsible for covering the nerve fibers. Consequently, there are various different symptoms an individual could possess depending on their age. Onset under age 2 typically occurs between 3 months to 2 years of age. Individuals can experience symptoms such as a particularly enlarged head (macrocephaly), muscle rigidity (spasticity), convulsions or seizures, and delayed development. For individuals with onset between ages 2 and 12, frequent symptoms include swallowing trouble, speech difficulties, poor coordination, and gradual cognitive decline. Finally, for individuals with onset at age 12 or later, which is one of the rarest forms of the disease, common symptoms include speech difficulties, swallowing difficulties, poor balance, and sleep disturbances.
Nevertheless, the drug to treat Alexander disease was only recently developed after three decades of research because scientists had to identify the genetic cause of Alexander disease and then wait for an advanced RNA-targeting technology to catch up with the disease. This process first began when two scientists Albee Messing and Michael Brenner discovered mutations in the GFAP (glial fibrillary acidic protein) gene that cause Alexander disease. Scientists and researchers then had to fully understand the mechanism of the disease, which is driven by the toxic overproduction and accumulation of GFAP protein within astrocytes in the brain. Subsequently, scientists had to wait for technologies such as antisense oligonucleotides (ASNs) and specialized RNA-targeting technologies to develop in order to safely interfere with and reduce the abnormal production of the protein at the genetic level. Finally, the rarity of the disease presented another challenge. Alexander disease is extremely rare, only affecting 0.000037% to 0.0001% of the global population, meaning that gathering enough participants for clinical trials required significant amounts of time and patience.
Therefore, all of these factors help explain why the drug used to treat Alexander disease, Zanvastro (zilganersen), developed by Ionis Pharmaceuticals, is financially inaccessible to the majority of the world. Zanvastro’s price is set at $285,000 per dose, and because patients require 4 doses per year, the treatment would cost approximately $1,140,000 per year.
https://news.wisc.edu/first-drug-to-treat-alexander-disease-approved-by-the-fda-after-three-decades-of-research-at-uw-madison/.
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