EU regulators have issued clearance for the first therapy to treat spinal muscular atrophy (SMA), a rare and often fatal genetic disease affecting muscle strength and movement.

The European Commission has approved Biogen's Spinraza (nusinersen) as a first line treatment of 5q SMA, the most common form of the disease which accounts for around 95 percent of all cases, following an accelerated assessment.

The decision was largely based on data from two pivotal multicenter, controlled studies, including end of study data from ENDEAR (infantile-onset SMA) and an interim analysis of CHERISH (later-onset SMA), which showed clinically meaningful efficacy and a favourable benefit-risk profile for the drug, according to the firm.

In the ENDEAR end of study analysis, a statistically significant greater percentage of patients achieved the definition of motor milestone responder in the Spinraza group (51 percent) compared to the sham-control group (0 percent), while infants given Biogen’s drug demonstrated a 47 percent reduction in the risk of death or permanent ventilation.

In the CHERISH interim analysis, a statistically significant and clinically meaningful improvement in motor function was observed in children with later-onset SMA (most likely to develop Type 2 or Type 3) treated with Spinraza compared to those who were untreated, with a treatment difference of 5.9 points in the mean change from baseline to Month 15 on the Hammersmith Functional Motor Scale Expanded (HFMSE).

“The overall clinical findings support the efficacy and safety of Spinraza in a broad range of individuals with SMA, including significant improvements in motor development and reduction in risk of death in infants,” said Prof. Dr. Jan Kirschner from the Medical Center University of Freiburg, Germany.

“These unprecedented improvements bring new hope to a community where there previously were no approved treatments available to address the loss of motor function over time. We are now seeing motor improvements with Spinraza that are never seen in the natural course of the disease.”