Biogen has been granted accelerated approval for QALSODY (tofersen) 100mg/15mL injection from the US Food and Drug Administration (FDA) for the treatment of a type of amyotrophic lateral sclerosis (ALS).
The approval is for the treatment of adults having a mutation in the superoxide dismutase 1 (SOD1) gene.
QALSODY is intrathecally administered as three loading doses given at 14-day intervals followed by maintenance doses provided once in 28 days thereafter.
The antisense oligonucleotide (ASO), has been designed to bind to SOD1 mRNA to reduce the production of SOD1 protein. It was discovered by Ionis Pharmaceuticals, which later signed a collaborative development and licensing deal with Biogen.
Tofersen’s efficacy was studied in the 28-week placebo-controlled VALOR clinical study in patients between 23 and 78 years with weakness caused by amyotrophic lateral sclerosis and a SOD1 mutation determined by a central laboratory.
A total of 108 patients were randomly grouped in a ratio of 2:1 to be subjected to either 100mg of the antisense oligonucleotide or placebo for 24 weeks.
Over 28 weeks in the VALOR trial, patients in the primary analysis population treated with QALSODY had less decline from baseline as measured by the Revised Amyotrophic Lateral Sclerosis Functional Rating Scale (ALSFRS-R). This is in comparison to placebo, though the results were not significant statistically.
In the overall intent-to-treat population, QALSODY-treated patients had reduction in plasma neurofilament light chain (NfL) by 55%, compared to an increase of 12% in participants subjected to placebo.
The accelerated approval has been given by the FDA based on reduction in plasma NfL shown in patients subject to QALSODY therapy.
Continued approval for the antisense oligonucleotide in the condition could be subject to verification of clinical benefit in confirmatory trial(s).
According to Biogen, the ongoing ATLAS phase 3 clinical study of tofersen in patients with presymptomatic SOD1-ALS will serve as the confirmatory trial.
Biogen president and CEO Christopher Viehbacher said: “For more than a decade, Biogen has been steadfast in our commitment to pursuing treatments for ALS, and I want to thank the scientists as well as the entire ALS community who have all worked tirelessly to bring this first-of-its-kind treatment to people with SOD1-ALS.
“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.”