Next-Generation Opportunities for Treating Rare Diseases
Although the definition of a rare disease in the US is one that affects fewer than 200,000 people, these conditions aren’t so rare – 400 million people globally are affected by a rare disease and around half of those affected are children. The prognosis for children with rare diseases is relatively poor, with three out 10 children not expected to live to see their fifth birthday.
Of the 7,000 distinct rare diseases that are known to exist today, only 5% have an approved treatment option. One reason for this is that developing drugs for rare diseases involves complexities not typically seen in clinical trials for more common conditions.
The main challenge is finding enough patients who fit the inclusion and exclusion criteria for a particular trial so that enough evidence can be gained to show the treatment is safe and effective. Add to this the challenge of diagnosing rare diseases, which typically takes between six to eight years, and it’s clear that we still have a long way to go to help these patients.
Historically, treatments for rare diseases have focused on minimizing or treating the symptoms with small molecule drugs or other therapeutics. This means that once diagnosed, patients have to undergo frequent administration of drugs to manage their condition.
For scientists working in the field, understanding the underlying pathophysiology of a rare disease is key to developing an effective treatment. There are numerous causes of rare diseases, but more than 80% have a known monogenic (single gene) origin. In some cases, these genetic changes are passed from one generation to the next, while others occur randomly.
Over the past couple of decades, discoveries at the molecular and genetic level have opened the door to novel therapeutic strategies that address the unmet needs of rare diseases. Innovations in technology have also led to the exploration of next-generation therapies, such as gene therapies, for the treatment of these conditions.
Targeting at the Genetic Level
Gene therapy involves the delivery of a corrected gene into the patient in vivo, or into a cell ex vivo. There are various methods of gene delivery, including direct injection of the DNA or RNA, chemical vehicles such as lipids and polymers, and viral vectors.
Advances in gene therapies have provided opportunities to potentially correct the genetic abnormalities that lead to rare diseases, thereby offering a cure rather than managing the symptoms. Currently, a number of inherited hematological, ophthalmological, and metabolic diseases are on the roadmap for molecular intervention and subsequent clinical trials using gene therapies.
To find out more about the strategies and opportunities gene therapy presents for rare diseases, download our latest whitepaper, ‘A New Era in the Therapeutic Journey – Gene Therapy as the Beacon for Rare Diseases’.