QALSODY Shows Unprecedented Functional Recovery in SOD1-ALS Patients Over 3.5 Years, JAMA Neurology Study Reports
Key Insights
Biogen's QALSODY (tofersen) demonstrated sustained clinical benefits over 3.5 years in SOD1-ALS (search) patients, with 27% of early-start participants experiencing muscle strength improvements previously unreported in the disease's natural history.
The Phase 3 VALOR study and open-label extension showed early QALSODY initiation was associated with slower decline in clinical function, breathing, and strength, plus reduced risk of death or permanent ventilation.
For faster-progressing participants, starting QALSODY just 6 months earlier was associated with a 3.4-year extension of event-free survival, highlighting the importance of early intervention.
Biogen's QALSODY (tofersen) has demonstrated unprecedented functional recovery in patients with SOD1 (search)-associated amyotrophic lateral sclerosis (search) (ALS (search)), according to final results from the Phase 3 VALOR study and its open-label extension published in JAMA Neurology. The long-term data, spanning over 3.5 years of follow-up, show that 27% of patients who started treatment early experienced improvements in muscle strength—something not previously reported in the natural history of SOD1-ALS (search).
Breakthrough Clinical Outcomes Challenge Disease Trajectory
The completed VALOR study and open-label extension (OLE) evaluated 108 participants with SOD1-ALS (search) over a median follow-up of 4.9 years. Early initiation of QALSODY was associated with numerically slower decline in measures of clinical function, breathing, and strength, as well as reduction in the risk of death or permanent ventilation.
"For people living with ALS (search), irreversible loss of muscle strength is a foundational symptom of the disease. In the QALSODY study, 27% of study participants in the early-start group experienced improvements in muscle strength over ~3 years," said Timothy Miller, M.D., Ph.D., principal investigator of VALOR and ALS Center Director at Washington University School of Medicine in St. Louis. "This just does not happen in ALS: In the past, conversations with people living with SOD1-ALS (search) were about how best to manage the progression of the disease, today these conversations include the potential for how to maximize improvement."
Timing Proves Critical for Treatment Efficacy
The study revealed striking differences based on treatment timing. For faster-progressing participants, initiation of QALSODY just 6 months earlier was associated with a 3.4-year extension of event-free survival, underscoring the critical importance of early intervention in SOD1-ALS (search).
"These final results illustrate what is possible with early initiation of QALSODY," said Merit Cudkowicz, M.D., co-principal investigator of the VALOR trial and co-founder of the Northeast ALS (search) Consortium. "In the faster-progressing participants, initiation of QALSODY just 6 months earlier was associated with a 3.4-year extension of event-free-survival. This makes all of us very excited about what we will learn from the presymptomatic ATLAS study where there is a possibility we could delay the onset of disease."
Sustained Biomarker Reductions Validate Mechanism
The study demonstrated sustained reductions in neurofilament light chain (search) (NfL), a marker of neurodegeneration, further validating the clinical results and demonstrating QALSODY's impact on the underlying biology of SOD1-ALS (search). These treatment-driven reductions in neurofilament are now being used as an early decision-making endpoint to accelerate future research.
"The final VALOR/OLE data further emphasize that, with the right target paired with the right therapeutic approach, we have the potential to meaningfully impact the course of ALS (search) and improve the outlook for people living with this devastating disease," said Stephanie Fradette, Pharm.D., Head of the Neuromuscular Development Unit at Biogen.
Safety Profile Remains Manageable
The most common adverse events were headache, procedural pain, fall, back pain, and extremity pain. Serious neurological adverse events of myelitis (search) or radiculitis (search), papilledema (search) and/or increased intracranial pressure, and chemical or aseptic meningitis (search) were reported in nine participants (8.7%). These events were manageable with standard of care and resolved, with only one myelitis event and one chemical meningitis event leading to treatment discontinuation.
Mechanism and Administration
QALSODY is an antisense oligonucleotide designed to bind to SOD1 (search) mRNA to reduce SOD1 protein production. In people with SOD1-ALS (search), mutations in their SOD1 gene cause their bodies to create a toxic misfolded form of SOD1 protein, which causes motor neurons to degenerate, resulting in progressive muscle weakness, loss of function, and eventually death.
The therapy is administered intrathecally as three loading doses at 14-day intervals followed by maintenance doses once every 28 days thereafter. QALSODY has received approval in 44 countries worldwide, including accelerated approval in the US based on reduction in plasma NfL.
Expanding Research Pipeline
SOD1-ALS (search) is diagnosed in approximately 2% of all ALS (search) cases, with about 330 people in the United States living with the disease. Beyond QALSODY, Biogen is studying the therapy in the Phase 3 ATLAS study to evaluate whether it can delay clinical onset of ALS when initiated in presymptomatic individuals with a SOD1 (search) genetic mutation and biomarker evidence of disease activity.
The company also maintains a robust discovery pipeline including efforts to address TDP43 pathology for the broad ALS (search) population, as TDP43 pathology is seen in 97% of ALS cases and is considered a hallmark of the disease.