the FDA handed Biogen, Ionis and particularly superoxide dismutase 1 (SOD1)-ALS patients a victory with the approval of Qalsody—formerly known as tofersen—as just the fourth therapy authorized in the U.S. for the devastating neurodegenerative disease.
The FDA approved Qalsody on a conditional basis under its accelerated approval pathway and will require Biogen to run an additional trial of patients who carry the SOD1 mutation but are not yet symptomatic.
Biogen won approval based on tofersen’s effect on neurofilament light chain (NfL), adding credibility to the neurodegenerative biomarker and establishing a path likely to be taken by other companies developing treatments for ALS.
In briefing documents released ahead of the FDA’s March advisory committee meeting on Biogen and Ionis’ tofersen, the agency called superoxide dismutase 1 (SOD1)-ALS “a very rare and devastating disease” and indicated the agency’s willingness to exercise regulatory flexibility. While supporting accelerated approval for tofersen, the FDA’s advisors voted 5-3, with one abstention, against traditional approval.
On Tuesday, Biogen, Ionis and the ALS community will find out whether tofersen will become the fourth FDA-approved ALS therapy.
In September 2022, Amylyx’s Relyvrio (AMX0035) became the third. Relyvrio’s approval was based on one randomized, controlled trial and came after the FDA’s Peripheral and Central Nervous System Drugs Advisory Committee initially voted against the drug in March 2022.
In a highly unusual second adcomm, spurred in part by a patient-driven email campaign, the advisers were convinced by confirmatory evidence from a post hoc analysis of data from the Phase II CENTAUR trial and open-label extension study.
Patient advocacy has also featured in tofersen’s story. The drug became a national name when Lisa Stockman Mauriello sought early access through the Right to Try Act in March 2021.
But there are also key differences between the two therapies.
Relyvrio is a proprietary combination of sodium phenylbutyrate and taurursodiol intended to reduce neuronal death and dysfunction. Tofersen, on the other hand, specifically aims to reduce production of the SOD1 protein, which is highly expressed in motor neurons. The underlying SOD1 gene is mutated in up to 20% of familial cases of ALS and 2% of all cases.
