In a landmark decision, the FDA has granted accelerated approval to Biogen's Qalsody (tofersen), the first-ever treatment specifically targeting a genetic form of amyotrophic lateral sclerosis (ALS) caused by mutations in the SOD1 gene. This approval represents a significant milestone in the treatment of rare genetic forms of neurodegenerative diseases.
The approval marks a pioneering shift in neurology therapeutics, as it is the first instance where a blood biomarker - neurofilament light chain (NfL) - has been used as the basis for accelerated approval. Clinical data showed that Qalsody reduced NfL levels by 55% over 28 weeks, compared to a 12% reduction with placebo, indicating a significant reduction in neuronal damage.
Clinical Development and Trial Results
The journey to approval wasn't straightforward. The VALOR trial initially missed its primary endpoint, which measured improvement in the Revised ALS Functional Rating Scale (ALSFRS-R) score. However, extended patient follow-up revealed clinically meaningful improvements over time. The FDA's expert advisory committee unanimously supported the use of NfL reduction as a reasonable predictor of clinical benefit.
Patient Impact and Market Access
SOD1-ALS affects approximately 330 people in the United States and is characterized by rapid progression and fatal outcomes. Biogen has committed to launching Qalsody within a week of approval, with patient out-of-pocket costs limited to $50 per month.
Ongoing Studies and Future Requirements
As part of the accelerated approval conditions, Biogen must provide additional evidence of clinical benefit to maintain market authorization. The company is currently conducting the phase 3 ATLAS trial, focusing on pre-symptomatic SOD1-ALS patients, with results expected in 2027.
Treatment Landscape Context
Qalsody joins a limited arsenal of ALS treatments, including Amylyx Pharmaceuticals' Relyvrio (priced at $158,000 per year) and Mitsubishi Tanabe Pharma's oral therapy Radicava (approximately $171,000 annually). While pricing details for Qalsody haven't been announced, Biogen indicates it will align with recent ALS treatment launches.
The Institute for Clinical and Economic Review (ICER) has previously raised concerns about the high costs of existing ALS treatments, highlighting the ongoing challenge of balancing innovative treatment access with healthcare economics.
