Last month, the pharmaceutical company Sarepta Therapeutics announced the long awaited results of a study that measured lung function in patients with Duchenne muscular dystrophy (DMD) after they took eteplirsen, a treatment developed by the company. The results showed that the treatment could significantly reduce the loss of breathing function in patients with the condition.
Duchenne muscular dystrophy is one of the most severe forms of muscular dystrophy. Muscle weakness is noticeable by age four and worsens quickly; most patients are unable to walk by their twelfth birthday. The disorder is x-linked recessive, so only boys develop this form completely. Scoliosis is a common symptom, and some patients may have intellectual disabilities as well. Most need breathing assistance as the respiratory muscles erode. This is the most common form of muscular dystrophy and most people with it are dead by their mid twenties. Like with all other forms, there is no cure for Duchenne muscular dystrophy. To learn more about this disease, click here.
While eteplirsen is not being touted as a cure for the condition, its ability to slow the decline of respiratory muscles still has significant implications. It has the potential to both improve the quality of life for those with DMD and to extend their lifespans.
Like all of Sarepta’s products, eteplirsen is a precise treatment that operates on the genetic level. The study was primarily meant to establish the safety and effectiveness of the treatment in the short term; long term safety has yet to be tested.
Only after more extensive testing is conducted will it be possible to establish that the drug has a substantive clinical benefit. The treatment works through a process called exon skipping, which allows the mutated parts of the gene to be skipped when it is transcribed to RNA. This allows for a version of the protein that, while not completely normal, is still more functional than it normally would be in the patient.
The fact that the treatment must be periodically reintroduced is a significant weakness, and is also part of the reason that further study must be conducted. Read more at biospace.com.