Biogen to file spinal muscular atrophy drug

Biogen has said it is to file nusinersen for spinal muscular atrophy (SMA) in infants after a phase 3 trial met primary endpoint.

Biogen developed the drug in partnership with Ionis, and has exercised an option to market the drug, paying the Californian biotech a $75 million license fee following results from the ENDEAR trial.

The trial success is a much-needed piece of good news for Biogen, at a time when CEO George Scangos has opted to move on, and a failure of multiple sclerosis drug opicinumab in a mid-stage trial.

Nusinersen is one of Biogen’s most attractive pipeline assets, according to Leerink Partners’ Geoffrey Porges, which predicts global sales of around $1.4 billion by 2020. Other analysts have also predicted annual sales in excess of $1 billion by that time.

At the moment, Biogen is reliant on its multiple sclerosis drug, Tecfidera (dimethyl fumarate) for a large tranche of its sales, and is looking to find alternative sources of income.

Biogen's biosimilars joint venture with Samsung, Samsung Bioepis, could also drive revenue growth in the future.

The ENDEAR trial evaluated nusinersen in infantile-onset (consistent with type 1) SMA, the leading genetic cause of infant mortality.

An interim analysis found infants receiving nusinersen experienced a statistically significant improvement in motor milestones compared to those who did not receive treatment.

The safety profile is “acceptable” according to Biogen, which plans to begin filings across the world in the coming months.

The ENDEAR study will be stopped early and participants will be able to tranisition into the SHINE open-label study in which all patients receive nusinersen.

Data from other endpoints will be analysed when the full data set is available, and presented at future medical meetings.

Participants on the placebo-controlled arm of the phase 2 EMBRACE study, which also included infantile-onset patients, will have the opportunity to receive nusinersen.

Other nusinersen studies, including CHERISH in later-onsent consistent with type 2, and NURTURE in pre-symptomatic infants, will continue as planned to collect safety and efficacy data in these populations.

SMA is a genetic condition that causes muscle weakness and progressive loss of movement. Caused by deterioration of motor neurones, the type 1 form of the disease is most severe and children with the disease rarely survive beyond two years of age.