Nusinersen Development for SMA Moves Forward

Biogen and Ionis Pharmaceuticals have recently issued several updates on the clinical development of nusinersen, an antisense drug designed to treat spinal muscular atrophy (SMA).

The partners announced that the enrollment period is now completed for both Phase 3 trials and for the Phase 2 study. Phase 3 trials remain on track for completion during the first half of 2017.

Nusinersen is currently being tested in two Phase III clinical trials: Cherish (childhood-onset) and Endear (infant-onset); and one Phase 2 study called Embrace.

Ionis recently presented additional data from an open-label Phase 2 study in infants at the latest American Academy of Neurology (AAN) 2016 Meeting. Cherish and Endear will now provide the necessary data for regulatory review and approval of nusinersen.

Also updated is the primary and secondary endpoints in the Endear trial protocol.

The Endear study was first designed with a primary endpoint of permanent ventilation-free survival, with observation for 13 months of nusinersen versus untreated patients. It then became clear that measuring motor milestones, endpoints of Children’s Hospital of Philadelphia Infant Test of Neuromuscular Disorders (CHOP INTEND) and Compound Muscle Action Potential (CMAP), could be useful indicators of nusinersen’s efficacy.

Now, Endear has an added primary endpoint: motor milestones. The changes were made after additional insight from the latest open-label studies and discussions with regulators and experts in the field throughout 2015.

An open-label called Shine, remains open for patients who have reached the end of Endear and Cherish trials and for patients finished with participation in the open-label Phase 2 trial for childhood-onset SMA.

According to the press release, Biogen and Ionis‘ next goal is getting access for nusinersen to eligible patients. The companies will open an expanded access program (EAP) as soon as possible.

Further updates will be announced at the Cure SMA Annual Conference, June 16-19, in Anaheim, Calif.