How long before I know if gene therapy is helping?

When people hear the word “therapy,” they often expect to feel a treatment effect right away. But in gene therapy, the goal is usually a little different: not a cure but instead slowing the progression – or stabilizing the disease.

OK, so what should I expect at first?
At first, it might seem like there’s little change. But in progressive diseases, holding steady matters. Over time, if the disease is progressing more slowly than expected, that’s meaningful and a sign the therapy is doing its job.

Why don’t I feel a change right away?
Gene therapy is designed to support your body in the months and years following treatment by helping it make a working protein. It isn’t meant to fix past damage, so you may not feel much impact from the gene therapy in the early days. That’s why starting treatment as early as possible is important, with the aim to preserve function and prevent further damage.

How will I know if it’s working?
The benefits of gene therapy are often seen over time. Researchers may compare a person who received gene therapy with people of the same age or disease stage who did not receive gene therapy. With time, the differences can become easier to see. Several years after treatment,
someone who received gene therapy may still be stable, while those who didn’t will be declining.

If gene therapy can slow or stop the disease from getting worse, then it is working as
intended.

Let’s review!

• Most gene therapies are designed to slow disease progression.
• This slowing of disease - not getting worse over time - can be a sign the therapy is working.
• Gene therapies cannot fix past damage.
• That’s why starting treatment early matters.
• It may help slow disease progression…
• …and preserve the remaining function for as long as possible.

If you have questions about gene therapy, talk to your healthcare provider or email our
Patient Affairs team at [email protected].