This month's Phase II data neither proved nor disproved AC Immune S.A.'s hypothesis that it could dial out enough toxicity in crenezumab to enable a higher, more efficacious dose for AD than previous anti-beta amyloid mAbs. The reason is that dosing apparently could have been higher.

Data presented on July 16 showed IV and subcutaneous crenezumab each missed the co-primary endpoints of reducing cognitive and functional decline vs. placebo in the Phase II ABBY trial. A 15 mg/kg dose of IV crenezumab did show trends toward treatment effects in patients with milder disease.