I think it needs to be higher. +4 is just what they got in moderate non-memantine patients after 13 weeks. If the drug actually reverses the decline it needs to be at least +6 after 28 weeks.
Here's what Derek Lowe had to say about the 2017 results:
"Furthermore, the test that the company makes much of is the Severe Impairment Battery (SIB). It's a 100-point scale, and the company says that the bryostatin-treated patients improved by 2.6 points on it at 13 weeks (difference between treatment group and placebo). Big deal. Aricept (donepezil), an approved Alzheimer's drug which is already known not to slow the progression of the disease one bit, but merely improve symptoms for a while, has an improvement of 5 SIB points at that same time point (as AndyBiotech noted from the drug's package insert)."
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