When can we expect an effective treatment for ALS—or even a cure?
When developing new drugs, there are two basic strategies to consider.
One initial strategy aims to develop drugs to treat known risk factors for ALS. To date, mutations in various genes have been identified as causes of ALS. In about 20% of all people with ALS, genetic changes are believed to cause ALS or at least increase the risk of developing the disease.
The most common mutations that can cause ALS are found in the SOD1 gene or the C9orf72 gene. The first gene therapy for mutations in the SOD1 gene (Tofersen) was approved in Germany in 2024. Tofersen can help slow the progression of ALS.
Mutations in the SOD1 gene were discovered as early as 1993. It would take more than 25 years of research to develop a pharmaceutical product for gene therapy based on the discovery of these SOD1 mutations.
It is considered very likely that the development of additional drugs (to treat FUS and C9orf72 mutations) will proceed more quickly. Scientific insights gained from SOD1 gene therapy can be applied to the development of FUS and C9orf72 gene therapies, thereby shortening the necessary development cycle.
Overall, it can be assumed that gene therapy will initially reach only a small number of patients. It is limited to those ALS patients who have mutations in ALS-associated genes.
A second strategy in drug development does not target the actual cause, but rather the ongoing disease process. This strategy aims to slow the process of damage to motor neurons or reduce the effects of neuron loss on the muscles.
This strategy involves developing drugs that aim to influence immune and metabolic processes and activate muscle function. This strategy is expected to be less effective (compared to gene therapy targeting causative mutations). However, this therapeutic strategy is suitable not only for selected patients with specific mutations but also for a broader group of patients.
Drugs designed to slow the progression of the disease are already undergoing clinical trials. These drugs are expected to be approved within a few years.
Certain forms of gene therapy, in which mutated genes are completely replaced (“gene transfer”) or genetic mutations are corrected within the cell nucleus (“DNA editing”), hold the fundamental potential to be highly effective therapies. It is not yet possible to estimate a timeline for these advanced genetic technologies either.
In the even longer term, it is conceivable and reasonable to assume that ALS will be fully understood and that a cure for the disease will be found.