Crenezumab, an anti-amyloid β (Abeta) antibody which Genentech in-licensed from AC Immune SA, failed to reach the primary endpoint of two phase II studies in Alzheimer's disease, but the drug has demonstrated tantalizing signs of efficacy in patients at the milder end of the Alzheimer's spectrum.
The main study, dubbed Abby, recruited 431 patients with mild-to-moderate disease, defined as a score of 18 to 26 on the 30-point mini-mental state examination (MMSE). (Individuals with a score of 27 to 30 points are considered normal).
In a subgroup analysis of 100 of these, with an MMSE score of 22 to 26 points, those on crenezumab (n = 70) had a 35.4 percent reduction in cognitive decline as measured by the Alzheimer's Disease Assessment Scale Cognitive subscale (ADASCog-12) vs. those on placebo (n = 30). The result was statistically significant (p = 0.036).
"It is extremely positive in the sense that it's one of the