24 Sep 2019

Gene therapy success in neuromuscular diseases

Illustration for article: Gene therapy success in neuromuscular diseases
The world has changed and the terrible diagnosis of spinal muscular atrophy communicated to parents now comes with a word that is full of hope: treatment.

The world has changed and the terrible diagnosis of spinal muscular atrophy communicated to parents now comes with a word that is full of hope: treatment.


For myotubular myopathy, the first results of a gene therapy trial are very encouraging. Without treatment, children’s survival is threatened within the first two years of their life. Now, a single injection of the gene-drug helps altering the natural progression of the disease. This is a landmark development!

Spinal muscular atrophy: the first gene therapy is available to patients

For the first time, gene therapy for a neuromuscular disease, namely spinal muscular atrophy, has received a marketing authorization in the United States, and is expected in Europe soon. A technology that emerged from research at Genethon.

How have we overcome spinal muscular atrophy?

1992: Starting point of the gene therapy saga. Genethon, the laboratory of AFM-Telethon, publishes the first maps of the human genome. This enables researchers around the world to accelerate the discovery of the genes responsible for diseases.  

1995: The enemy is identified. Judith Melki, a French researcher, identifies the gene responsible for spinal muscular atrophy, thanks to the donations collected during the Telethon.

2004-2011: Within Genethon, a team tackles the development of gene therapy and proves its effectiveness to repair motor neurons in mice suffering from this disease.

2015-2017: Clinical trials begin. The first children receive treatment and show very positive results. Children who receive treatment earlier at birth take their first steps. Something that was unthinkable until then.

2019: Major victory. This gene therapy treatment is authorized for the most severe form of spinal muscular atrophy.


Augustin: pioneer of gene therapy

Augustin is three and a half months when he is diagnosed with spinal muscular atrophy type 1, the most severe form of this neuromuscular disease which progressively deprives children from their strength, their respiratory capacities, and threatens their survival before the age of two.

Despite his very young age, Augustin is a pioneer! At five months old, he benefited from the gene therapy treatment authorized a few months ago in the United States, and very soon in Europe. A revolutionary treatment which, in a single injection, saves children’s lives!

“We’ve been fortunate to benefit from this treatment, this is exceptional! We had to react very fast, because each day mattered for the treatment to be as effective as possible. Now, we just hope that Augustin gains strength each day”,

Says his mother, mindful of this major therapeutic breakthrough, which has emerged from the work done at Genethon.

Since his injection, Augustin is monitored on a monthly basis and has three sessions of physical therapy per week. The first results appear!

For two years, a real medical revolution has taken place for spinal muscular atrophy. Thanks to the first available treatments, children who were condemned by the disease live and gain or regain motor function. But we know that today: the earlier children receive treatment, even before their first symptoms, the more chances there are to stop the progression of the disease, or even to cure it. Hence, newborns who received treatment right after their first symptoms can achieve a near normal motor development. 

Find out more: Spinal muscular atrophy is a rare genetic disease, neuromuscular, which affects motor neurons resulting in the progressive atrophy of muscles. Several forms of the disease exist, which are characterized by weakness and early-onset atrophy of the pelvis, shoulder, trunk, arm and leg muscles. In the most severe forms, intercostal muscles are paralyzed and ventilation support may be required to breathe, even at a very young age. Spinal muscular atrophy type 1 is fatal before the age of two.


Myotubular myopathy: a step forward and a real hope for the future

Another neuromuscular disease declines thanks to a gene therapy capable of treating the entire body in a single injection. Thanks to the drug developed by Genethon, 9 children who received treatment gained greater autonomy and their general condition improved. A victory!

“To this day, 9 children have received treatment worldwide. There is evidence of a very significant improvement of the respiratory function and muscle strength, which resulted in the acquisition of new capabilities such as sitting down, grabbing objects… It is wonderful to see that some children can stand”.   

Confides Ana Buj-Bello, the Genethon researcher who developed the treatment for myotubular myopathy.

Key steps:

1996: The hunt can begin. With the support of AFM-Telethon, French researchers discover the gene responsible for myotubular myopathy.

1997-2014: Research and find. Ana Buj-Bello is a determined researcher. After proving that gene therapy is effective in mice, she proves that it is effective in large animal models.

2017: Prize-winning work. A first clinical trial in children begins.

2018-2019: Spectacular results. Children who receive treatment regain respiratory and muscle capacities.

Find out more: Myotubular myopathy is an X-linked genetic disease affecting 1 in 50,000 male births. It is due to mutations in the MTM1 gene coding for myotubularin, a protein involved in the functioning of muscle cells. It is characterized by a severe muscle weakness and respiratory failure. Fifty percent of affected children die before they reach the age of 18 months.