Biogen's Qalsody Approved in Europe for Rare ALS

Biogen has announced the European Commission's approval of Qalsody (tofersen) for treating amyotrophic lateral sclerosis (ALS) linked to SOD1 gene mutations, which accounts for approximately 2% of all ALS cases. This approval follows the European Medicines Agency's endorsement of the drug in February and establishes Qalsody as the second authorised ALS treatment in the European Union, alongside Sanofi's Rilutek (riluzole). According to the European Organisation for Professionals and People living with ALS, Qalsody is also notable as the first treatment targeting a genetic cause of the disease.

The approval of Qalsody is based on findings from the Phase III VALOR trial. This study demonstrated that Qalsody could reduce the mean plasma level of neurofilament light chain (NfL)—a biomarker indicative of axonal injury and neurodegeneration—by 55% after 28 weeks, compared to a 12% increase observed in patients given a placebo. Despite this significant reduction in NfL levels, the trial did not meet its primary endpoint, which was an improvement in the ALS Functional Ratings Scale-Revised total score. Although Qalsody showed a numerically higher mean change compared to the placebo, the difference was not statistically significant.

The European Commission's decision to approve Qalsody comes a year after the U.S. Food and Drug Administration (FDA) granted the drug accelerated approval for the same patient group. The FDA's decision was based on the reasoning that reductions in NfL levels were "reasonably likely to predict a clinical benefit in patients."

Qalsody, an antisense oligonucleotide, targets the SOD1 gene mutations, which are implicated in a small subset of ALS cases. This genetic targeting sets it apart from existing treatments, marking a significant step forward in addressing the genetic underpinnings of ALS. The drug's approval signifies a meaningful addition to the limited treatment options available for ALS patients, particularly those with SOD1 gene mutations.

The VALOR trial, which included 108 participants, provided essential data supporting the efficacy of Qalsody. Although the trial did not achieve its primary endpoint, the marked reduction in NfL levels offers a compelling rationale for its clinical benefits. The European Medicines Agency's earlier endorsement and subsequent approval by the European Commission reflect a cautious optimism about the drug's potential.

The broader ALS community, including medical professionals and patients, has welcomed the approval of Qalsody. It represents a hopeful advancement in the management of a debilitating and currently incurable disease. The ability to target a genetic cause of ALS may pave the way for more personalized and effective treatments in the future.

In conclusion, the European Commission's approval of Qalsody is a pivotal moment for ALS treatment, particularly for those affected by SOD1 gene mutations. While its impact on functional outcomes remains to be conclusively demonstrated, the significant reduction in NfL levels is a promising indicator of its potential to alter the disease's progression. This approval not only expands the arsenal of available therapies but also underscores the importance of continued research and innovation in the fight against ALS.