Biogen and Ionis Pharmaceuticals’ Phase 3 study of Spinraza (nusinersen) for the treatment of later-onset spinal muscular atrophy (SMA) met its primary endpoint.
The Phase 3 study is a 15-month study investigating the orphan drug in 126 non-ambulatory patients diagnosed with later-onset SMA, which includes patients with the onset of signs and symptoms greater than 6 months and an age of 2 to 12 years at screening.
Patients who received nusinersen experienced a highly statistically significant improvement in motor function compared to those who did not receive treatment.
The patients that were administered nusinersen, demonstrated a difference of 5.9 points (P = 0.0000002) at 15 months between the treatment (n=84) and sham-controlled (n=42) study arms, as measured by the Hammersmith Functional Motor Scale Expanded (HFMSE) (a tool designed to assess motor function in children with SMA).
Treated patients achieved a mean improvement of 4.0 points in the HFMSE, while patients who were not on treatment declined by a mean of 1.9 points.
Participants in the study will be able to participate in the extension study to receiver nusinersen.
Since the Phase 3 trial met its primary endpoint, Biogen’s stock is now at $295.02 with a price increase of 18.02 (6.51%).
Ionis’ stock is at $31.82 Price increase 4.69 (17.29%).
Spinraza (nusinersen) is an antisense oligonucleotide (ASO) that is designed to alter the splicing of pre-mRNA from the SMN2 gene in order to increase production of fully functional SMN protein. Nusinersen is being investigated in Type I, II, and III SMA populations.
About Spinal Muscular Atrophy
SMA is a genetic condition that leads to a deficiency in the spinal motor neuron (SMN) protein as a result of mutations of the survival motor neuron 1 (SMN1) gene. The severity of SMA correlates with the amount of SMN protein. Generally, the muscles most affected are those near the shoulders, hips, thighs and upper back. Muscles used for breathing and swallowing may also be affected. Infants with Type I SMA produce very little SMN protein and have a life expectancy of less than two years. Children with Type II have greater amounts of SMN protein but still have a shortened lifespan and are never able to stand independently. Children with Type III have a normal lifespan but accumulate life-long physical disabilities as they grow.