Early Spinraza Treatment for SMA Leads to Improved Motor Function, Biogen Says

Spinraza (nusinersen) may provide more benefits to infants with spinal muscular atrophy (SMA) if the treatment is started early, Biogen reported during presentations at the ongoing 22nd International Congress of the World Muscle Society in St. Malo, France.

But the treatment can also provide benefits to SMA patients in other disease stages, according to an interim analysis of data from the Phase 2 EMBRACE trial (NCT02462759).

“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,” Alfred Sandrock, MD, PhD, executive vice president and chief medical officer at Biogen, said 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,” he added.

In the Phase 3 ENDEAR trial (NCT02193074), which included infants, researchers measured differences in motor milestones with a tool called the Hammersmith Infant Neurological Examination (HINE). In the group of infants with a disease duration of 12 weeks or less, 75% of Spinraza-treated children achieved motor milestones compared to untreated children.

In the group that had been ill for more than 12 weeks before starting treatment, the number was 32%.

The EMBRACE interim analysis showed that Spinraza treatment allowed more infants and children to reach motor milestones compared to untreated patients. The study also provided evidence that supported a dosing schedule of four so-called loading doses (to quickly increase drug concentration in the body) in the first two months, followed by Spinraza injections every four months.

Safety analyses showed that in children with later stage SMA who had developed a curved spine, or scoliosis, the spinal injections gave rise to similar side effects as in children without scoliosis.

Spinraza was approved in the U.S. in December 2016, supported by results from the ENDEAR trial, and by data from open-label studies in a range of patients (ages 30 days to 15 years) and in infants (ages 8 to 42 days old) who were presymptomatic but thought likely to develop SMA types 1, 2 or 3.  European regulators approved the drug in June 2017.

Biogen continues to analyze data from these trials, as well the Phase 3 CHERISH (NCT02292537) study in later-onset SMA. Meanwhile, health insurance companies increasingly are endorsing the treatment. In June, the company reported that infants who do not yet show SMA symptoms also benefit from the treatment.