Biogen's Qalsody (tofersen) has received FDA approval as the first treatment to target a genetic cause of amyotrophic lateral sclerosis (ALS). The approval, granted on Tuesday, targets a specific and devastating ultra-rare genetic form of the progressive neurodegenerative disease.
Qalsody is indicated for the treatment of ALS in adults who have a mutation in the superoxide dismutase 1 (SOD1) gene. This approval marks a significant advancement, offering a therapy that addresses the underlying genetic cause of SOD1-ALS, which affects approximately 2% of all ALS cases, or about 330 people in the U.S.
Mechanism of Action and Clinical Evidence
The FDA's decision was primarily based on the observed reduction in plasma neurofilament light chain levels in patients treated with Qalsody. Neurofilaments are proteins released from neurons upon damage, serving as a marker for neurodegeneration. The clinical trial data demonstrated that Qalsody effectively lowered these neurofilament levels, suggesting a potential slowing of disease progression.
Christopher Viehbacher, Biogen’s president and CEO, emphasized the importance of this milestone, stating, "Today also marks a pivotal moment in ALS research as we gained, for the first time, consensus that neurofilament can be used as a surrogate marker reasonably likely to predict clinical benefit in SOD1-ALS. We believe this important scientific advancement will further accelerate innovative drug development for ALS."
Administration and Target Population
Qalsody is administered via spinal injection by healthcare professionals experienced in performing lumbar punctures. SOD1-ALS is a progressive neurodegenerative disease characterized by the degeneration of nerve cells controlling voluntary muscles, leading to muscle weakness and paralysis. The therapy aims to mitigate the effects of the SOD1 mutation, which causes the production of a toxic protein that damages motor neurons.
Community Impact
Jean Swidler, chair of Genetic ALS & FTD: End the Legacy, highlighted the significance of this approval for families affected by SOD1-ALS, noting, "Qalsody offers families who have lost generation after generation in the prime of their life to this devastating disease a therapy targeting the underlying cause of SOD1-ALS."
Broader Context of ALS Treatment
This approval follows the FDA's recent approval of Amylyx Pharmaceuticals' Relyvrio, another ALS treatment, underscoring the increasing momentum in developing therapies for this challenging disease. With an estimated 30,000 people in the U.S. living with ALS, the development of new treatments offers hope for improved outcomes and quality of life.
