Although inotersen met efficacy endpoints in Phase III familial amyloidosis study, adverse event rates raised a red flag and give Alnylam's competing patisiran an edge on safety, at least for now.

Open-label extension Phase II data with RNAi candidate shows patients with transthyretin-mediated amyloidosis polyneuropathy may be regaining sensation and possibly even regenerating nerves.

Clinical trial failures and holds for drugs derived from nucleic acids from Alnylam and Ionis join those of Dicerna and Genta as the hit rate for these drugs continues to degrade. The real question is whether the failures have been due to a lack of efficacy or safety.