Challenges Remain in Duchenne Muscular Dystrophy Drug Development

Duchenne Muscular Dystrophy (DMD) is the most common type of the 9 types of muscular dystrophy. It is a genetic disorder that causes muscle degeneration and weakness. It is a progressive genetic disorder primarily found in boys and is usually diagnosed early, between the ages of 3 and 5. There is no cure.
Challenges to find effective treatment exist for most of the 7,000 rare diseases that the Center for Disease Control and Prevention recognize. Each of these diseases, as per their classification, do not have a very large patient population, but collectively they represent over 30 million people in the United States. DMD also faces challenges for companies attempting to bring new therapies to the market.

According to a recent article on The Rare Disease Report website, one of the biggest challenges to discovering new treatments, including those for DMD, is the small patient populations from which clinical researchers draw their patients.

There are several additional factors, besides small patient populations, that hinder researchers in their quest to fill clinical trials for DMD therapies:
  1. Limited study sites mean patients have to travel to be included, which may create an additional barrier to enrolling patients for trials.
  2. Small patient populations mean limited data on the disease, its symptoms and their affect on quality of life for patients.
  3. Clinical trial planning and design is also negatively affected by small DMD patient populations, because of the lack of previous trials in which to guide trial development.
  4. DMD is a progressive disease that can advance very quickly in some cases.
  5. Many of the DMD patients are children. This fact brings about other challenges in designing and implementing clinical trials.
  6. The endpoints of some clinical trials do not correspond well to measuring the improvement in the general health and quality of life of the patients in the trials.
Review process needs to change

The biggest change to the review process should center around the voice of the patient. The patients and their caregivers may be able to shed light on meaningful improvements in quality of life that the trials endpoints don’t measure. Just because a trial misses its primary objectives, doesn’t mean that it fails for patients with rare diseases such as DMD. The subjective data from patients, care givers and healthcare providers may be able to shed light on improvements that aren’t measured in our currently accepted process for treatment review.

The U.S. Food and Drug Administration has made some inroads to providing more flexibility in the regulatory review process. In 2012, the Safety and Improvement Act (FDASIA) was adopted by the FDA. In 2016, they introduced The 21st Century Cures Act of 2016. Both of these acts were intended to provide a more flexible review process that takes into account the patient voice, when there is a absence of or clinical data that is relevant to the approval process.

In the past few years, the life expectancy of patients with DMD has been increased. DMD patients who might have died in their teenager years may now live into their late 20’s and early 30’s. Advances in pulmonary and cardiac care has made this possible. Hopefully, with more a more flexible model for regulatory approval in place, these patients can have an extended life expectancy and better quality of life than in the past.

Donald Blake

Donald Blake

Donald Blake has a BS in Communication Studies. He has a lengthy tenure in the healthcare, media and education fields. He is dedicated to improving the lives of those with rare diseases through his knowledge of healthcare and communications.

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