Biogen recently announced that the U.S. Food and Drug Administration (FDA) has granted Breakthrough Therapy Designation to salanersen, an investigational therapy being studied for the treatment of spinal muscular atrophy (SMA). This designation is intended to help speed the development and review of drugs that show early promise in treating serious conditions.
Salanersen is an antisense oligonucleotide (ASO) — a type of therapy designed to help the body produce more of the SMN protein that people with SMA are missing. What makes salanersen unique is that it's administered just once a year and uses a new chemistry that may allow for high efficacy with an infrequent dosing schedule.
The FDA's decision is based on data from a Phase 1b study in children with SMA who had a suboptimal response to prior gene therapy. After receiving salanersen, many of these children experienced meaningful improvements in motor function, including gaining new abilities like sitting and walking, as well as a reduction in neurofilament light chain levels, a potential marker of ongoing nerve damage. Half of the 24 participants in the study achieved at least one new motor milestone, and all participants maintained the milestones they had when the study began.
Cure SMA's President, Kenneth Hobby, responded to the news:
"This designation reflects the FDA's continued commitment to SMA and its recognition of the potential meaningful impact salanersen may offer. It affirms what our SMA community has recently communicated to the agency: urgent, unmet needs remain, and promising therapies deserve a rapid path forward."
Biogen is now advancing three global Phase 3 studies for salanersen — STELLAR-1, STELLAR-2, and SOLAR — which together are designed to evaluate salanersen across a broad range of people living with SMA, from presymptomatic infants to teens and adults.
Read the full press release from Biogen here.