Improving how scientists identify new potential treatments for FSHD

Facioscapulohumeral muscular dystrophy (FSHD) is a condition where a gene called DUX4 is wrongly switched on in muscle cells. This causes the muscles to become damaged and weak over time. Scientists are working on treatments to block DUX4, and some have already been tested in clinical trials.

One treatment called losmapimod looked like it might work in early lab tests. These tests used models – ways for scientists to study a condition and try out treatments safely before testing them in people. Models are made to behave like the condition does in the body. They can be muscle cells grown in dishes or animals that show similar symptoms.

But when losmapimod was tested in people, it didn’t work as expected. This shows that even if a treatment works in models, it might not always in people. That’s why scientists are looking for better ways to test new treatments. This is especially important now, as more potential treatments are being discovered and scientists need better ways to choose the ones to take forward for testing in people.

To help with this, scientists found a way to put human muscle cells into mice. These cells grow into real human muscle that works and can even repair itself. This is much closer to what happens in the human body, so it gives scientists a better chance of seeing whether a treatment will work before testing it in people.

Dr Virginie Mariot will train her team to build and use a new model in their lab by placing human muscle cells affected by FSHD into mice.

Scientists are finally starting to find new treatments that could help people with FSHD. But so far, treatments that look promising in early lab tests didn’t work when they were tested in people.

This project could help scientists build a better way to test treatments. It will help them see how the condition affects real muscle and find out which treatments are most likely to help. In the future, this could help them choose the best ones to move forward into clinical trials, potentially saving time and money, and bringing new treatments to people with FSHD sooner.