Rare Diseases

The aim of gene therapy is to fix a faulty gene, or replace it with a healthy copy, to help treat or improve the disease. Rather than treating symptoms, these therapies aim to treat the underlying genetic cause of the disorder with just one or a few treatments over time. Many rare diseases are caused by changes (or mutations) in a single gene, so gene therapy has the potential to make a big difference. Gene therapies can work in several ways:

• Replacing a disease-causing gene with a healthy copy of the gene
• Inactivating a disease-causing gene that is not working properly
• Adding a new or modified gene into the body to help treat a disease

However, gene therapy may not always work. And once it is given, it cannot be stopped or taken out.

More than 95% of rare diseases have no treatment (citation: https://rarediseases.org/living-with-a-rare-disease/clinical-trials/). As a result, clinical trials are needed to find new or better treatment options.

These clinical trials are often small because there are few people with the disease or condition. It is difficult to enroll enough participants for a meaningful analysis using a traditional clinical trial design which typically requires a large number of participants. As a result, researchers develop new clinical trial designs that work with smaller populations to yield meaningful results. These designs often involve a more personalized approach to meet the needs of a small patient group.

A natural history study is a type of non-interventional study. Natural history studies help researchers better understand a specific disease or condition. These studies watch how the disease naturally progresses over time, without giving any investigational treatment or intervention. They are important for rare diseases, like those being studied in the gene therapy. These studies are done because researchers may not yet fully understand how the condition affects people in the short and long term.