Ionis Pharmaceuticals (NASDAQ:IONS) is up 37% today after announcing positive phase 3 trial results for nusinersen in infants with spinal muscular atrophy. The results convinced partner Biogen (NASDAQ:BIIB) to exercise its option to license nusinersen, triggering a $75 million payment to Ionis Pharmaceuticals.No actual details were presented in the press release or accompanying conference call because this was an interim analysis, and the companies are holding the data for an upcoming medical meeting.Biogen and Ionis Pharmaceuticals noted that nusinersen met its primary endpoint of achieving motor milestones compared to the control group. With it clear that the drug is working, the clinical trial was stopped early to allow the infants receiving placebo to transition to nusinersen.37 per cent rise it not too big for a pharma company over such news - 50-90 per cent in such cases isn't uncommon also, so I think these gains might hold on and bring more gains