Arrowhead's ARO-MAPT Cuts Tau Up to 85% in First Blood-Brain Barrier siRNA Success
ARWR sits 72% above its 52-week low of $34.61.
Summary
Arrowhead reported interim Phase 1/2a data for ARO-MAPT showing deep, durable tau reductions in healthy volunteers — mean CSF total tau down up to 73% at Day 105, with a maximum of 85%. This is the first clinical validation of siRNA delivery across the blood-brain barrier, a major scientific milestone that could open the entire CNS space to Arrowhead's TRiM platform. Safety was clean: no serious adverse events, no persistent anemia or neurobehavioral issues. The durability supports dosing once every three months or less. This follows a strong run of plozasiran data and regulatory wins, but ARO-MAPT targets Alzheimer's and tauopathies — a far larger market. Part 2 in early Alzheimer's patients is already enrolling, with data updates expected in 2027. The company will host a webinar today at 2:30 pm ET to review additional results.
At the time of this announcement, ARWR was trading at $59.45 on NASDAQ in the Life Sciences sector, with a market capitalization of approximately $8.2B. The 52-week trading range was $34.61 to $95.49. This news item was assessed with positive market sentiment and an importance score of 9 out of 10. Source: BusinessWire.