Yes, and I am somewhat biased the way your sentiment suggests.  What is not clear to me is how many patients were dosed with this high potency and that is where your point may be valid.  FWIW, here is the relevant cut & paste from Biogen's press release today.  The 23% to 27% vs placebo sounds great as does the 0.01 P.  

In EMERGE, which met its pre-specified primary endpoint in the new analysis, patients treated with high dose aducanumab showed a significant reduction of clinical decline from baseline in CDR-SB scores at 78 weeks (23% versus placebo, P=0.01). In EMERGE, patients treated with high dose aducanumab also showed a consistent reduction of clinical decline as measured by the pre-specified secondary endpoints: the Mini-Mental State Examination (MMSE; 15% versus placebo, P=0.06), the AD Assessment Scale-Cognitive Subscale 13 Items (ADAS-Cog 13; 27% versus placebo, P=0.01), and the AD Cooperative Study-Activities of Daily Living Inventory Mild Cognitive Impairment Version (ADCS-ADL-MCI; 40% versus placebo, P=0.001). Imaging of amyloid plaque deposition in EMERGE demonstrated that amyloid plaque burden was reduced with low and high dose aducanumab compared to placebo at 26 and 78 weeks (P<0.001). Additional biomarker data of tau levels in the cerebrospinal fluid supported these clinical findings. Biogen believes that data from patients in ENGAGE who achieved sufficient exposure to high dose aducanumab supported the findings of EMERGE.