It has been deemed one of the most controversial drug approvals in recent history, but when the FDA approved Sarepta Therapeutics’ Exondys 51, on the 19th of September, 2016, Duchenne muscular dystrophy (DMD) patients, their families, and the advocacy groups that support them, were elated. It was considered a huge win for the patient community, who had lobbied hard for the new treatment, and it provided hope for other rare disease patients still waiting for approved treatment options for their conditions.
However, now that the initial hullabaloo has calmed down a bit, it is important to evaluate what this drug approval actually means for the DMD community. Has it really led to marked improvements in the lives of the 1 in every 3,500 to 6,000 males that are born each year in US with the disease?
The short answer is no, not really. There have, of course, been boys that have responded well to the drug, and, for them, Exondys 51 has been a blessing. But the reality is that, this drug helps only 13% of the DMD community. The treatment was designed based on an exon skipping technique, which helps determine which exons to skip in order to correct the genetic mutation associated with the disease. However, it only works for patients who have a particular mutation of the dystrophin gene that is amenable to exon 51 skipping. For 87% of the young boys suffering from this disease, that is not the case, rendering the drug ineffective for them.
CureDuchenne, a leading DMD advocacy group, which played a significant role in encouraging the FDA to approve Exondys 51, has recognized that one approved treatment option is not enough to help every DMD patient. They are now working tirelessly to ensure that the impetus does not wear off after this one approval, and have launched a campaign called “I am the 87%” which aims to raise continued awareness of the disease, as well as funding to support further research into another treatment for the remaining DMD patients.
However, unfortunately, the issue is not just that most of the boys are unable to benefit from the drug. Another significant issue is that many of the big-name insurance companies are refusing to cover the drug, leaving patients and their families unable to afford it. Such insurance companies are claiming that the drug was approved based on insubstantial clinical evidence, meaning there is uncertainty about whether the drug actually works. For a drug that is expected to cost $300,000 per patient per year, healthcare coverage is a huge must for many families, and this announcement by insurance companies will most likely serve as a huge blow.
The DMD community are determined, however, not to let these issues stand in their way, and are remaining optimistic about the future. One parent of a DMD patient has been quoted saying, “there is now hope for our boys with Duchenne […] Research is starting to show results […and] there is hope that my son and hundreds of other young me like him, will live full and rewarding lives.”