Piper Jaffray analyst Joshua Schimmer noted that Biogen presented additional detailed analyses from the ongoing Phase 1b PRIME study in Alzheimer's disease and said the clinical data is increasingly supportive of aducanumab's benefit. While some questions remain, Schimmer is "increasingly confident" that Biogen has "cracked the code on this important unmet need with a safety profile that is adequate relative to the disease process." The analyst adds that there may be a bit of a data vacuum from this program until later in 2018, though he also expects SPINRAZA to provide near-term positive catalysts for Biogen, on which he keeps an Overweight rating.