At the 22nd
International Annual Congress of the World Muscle Society in France, Biogen presented new data that demonstrates that starting treatment with Spinraza (nusinersen) earlier than later improves motor function outcomes in children with spinal muscular atrophy (SMA).
In December 2016, Spinraza was approved to treat both patients with SMA after its safety and efficacy were confirmed in a clinical trial in which it was administered to 121 patients with infantile-onset SMA.
New data from the Phase 3 ENDEAR
study, a randomized, double-blind, sham-procedure controlled 13-month study in patients with infantile-onset SMA, showed that the drug improved motor function outcomes in infants with the disease.
SMA is a genetic condition characterized by the loss of motor neurons in the spinal cord and lower brain stem. Mutations in the survival motor neuron (SMN1) gene frequently result in a deficiency in the spinal motor neuron (SMN) protein. Severity of the condition varies from patient to patient, but the muscles most commonly affected include those near the shoulders, hips, thighs, and upper back.
Infants with Type I SMA, the most severe variation of the condition, produce very little SMN protein and have a life expectancy of less than 2 year. Children with Type II SMA have more of the protein, but are still subject to a shortened lifespan and are never capable of standing without assistance. Children with Type III SMA have a normal lifespan, but accumulate lifelong physical disabilities.
The new data was found using the Hammersmith Infant Neurological Examination (HINE) to assess motor milestone achievement in infants with SMA who began treatment within 12 weeks of diagnosis and those who began treatment after 12 weeks of diagnosis. In the study, 75% of patients who began treatment early had motor milestone acheivements in comparison to 32% of patients who began treatment later. As a reference, 0% of patients who did not receive Spinraza showed motor milestone acheivements.
Additionally, a meaningful benefit in in event-free survival in infants treated with Spinraza with disease duration less than or equal to 12 weeks (P=.0004) was also reported.
“These studies contribute to a growing body of evidence that Spinraza can make a meaningful difference in the lives of people with SMA regardless of their age or stage of the disease,” said Alfred Sandrock, M.D., Ph.D., executive vice president and chief medical officer at Biogen in a press release
. “Across studies, we continue to see evidence that earlier initiation of treatment with Spinraza can lead to improved clinical and functional outcomes.”
In addition to data from the ENDEAR study, Biogen is also presenting data in France that pertains to the company’s Phase 2 EMBRACE
study. Results from the 14-month trial represent a cohort of infants and children not eligible to participate in ENDEAR or Biogen's other Phase 3, the CHERISH study, and indicate that the drug is responsible for greater motor milestone achievement in infants and children, compared to those untreated.
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