# Arrowhead Pharmaceuticals Reports Up to 85% Tau Reduction in Early Trial

- URL: https://stocks.freetheai.org/news/arrowhead-pharmaceuticals-reports-up-to-85-tau-reduction-in-early-trial-da0113
- Published: 2026-10-14T11:30:00Z
- Category: company_news; sentiment: mixed; impact: medium
- Symbols: [NASDAQ:ARWR](https://stocks.freetheai.org/symbols/NASDAQ-ARWR)
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Arrowhead Pharmaceuticals, Inc. (ARWR) released interim Phase 1/2a trial results for its investigational drug ARO-MAPT, which demonstrated significant reductions in tau protein levels among healthy volunteers. Delivered via subcutaneous injection, the therapy achieved an average total tau reduction of up to 73% in cerebrospinal fluid at Day 105, with peak drops reaching 85%. Early safety findings showed the drug was generally well tolerated.

The trial marks an initial step in validating the company's central nervous system RNA interference delivery platform. Achieving target engagement with an under-the-skin injection could offer a less invasive route for addressing neurological disease markers. Following the announcement, Arrowhead Pharmaceuticals shares fell 4.28% to $58.13 in trading.

Looking ahead, the long-term clinical impact remains to be seen as patient trials progress. Arrowhead plans to report results from Alzheimer's disease patients in 2027, and executive leadership is hosting a question-and-answer webinar today to discuss the interim findings.

## Key points

- ARO-MAPT reduced cerebrospinal fluid tau levels by a mean of up to 73% at Day 105, reaching a maximum drop of 85%.
- The interim Phase 1/2a study evaluated healthy volunteers who received the treatment through subcutaneous injections.
- Early safety observations showed that the experimental drug was generally well tolerated by participants.
- Results from trials in patients with Alzheimer's disease are projected for release in 2027.
- Shares of Arrowhead Pharmaceuticals, Inc. (NASDAQ:ARWR) fell 4.28% to $58.13 following the news release.

## Questions and answers

### What were the main findings from Arrowhead's ARO-MAPT trial?

Interim Phase 1/2a data in healthy volunteers showed that subcutaneous ARO-MAPT cut cerebrospinal fluid total tau by an average of up to 73% at Day 105, with a maximum reduction of 85%.

### When will patient data for Alzheimer's disease be available?

Arrowhead Pharmaceuticals expects data from Alzheimer's disease patients to be available in 2027.

### How is Arrowhead's drug ARO-MAPT administered?

ARO-MAPT is delivered via subcutaneous injection.