secwatch.observer — SEC 8-K summary
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Issuer:     Alto Neuroscience, Inc. (ANRO)
CIK:        0001999480
Form:       8-K
Filed at:   2025-06-26T23:59:59+00:00
Accession:  0001999480-25-000053
Event type: other_material
Sentiment:  positive
Materiality: 0.65
Item codes: 8.01, 9.01
LLM model:  deepseek-v4-flash:cloud@v2

Alto Neuroscience identifies EEG biomarker and positive Phase 2 results for ALTO-203 in MDD
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- ALTO-203 showed pro-cognitive and wake-promoting effects; EEG theta/beta ratio confirmed as key biomarker (25µg: p<0.05).
- Improvements in sustained attention replicated Phase 1 findings; greatest in patients with high baseline theta/beta ratio (25µg: p<0.01; 75µg: p<0.05).
- Objective sleep measures from wearables confirmed wake-promotion; both doses significant (25µg: p<0.05; 75µg: p<0.001 vs placebo).
- MADRS improvements were small (25µg: -2 points at week 3 vs placebo) but trial not powered for significance.
- Safety profile: well tolerated, insomnia most common adverse event; predictable PK.

Source:
  EDGAR index:    https://www.sec.gov/Archives/edgar/data/1999480/000199948025000053/0001999480-25-000053-index.htm
  Primary doc:    https://www.sec.gov/Archives/edgar/data/1999480/000199948025000053/alto-20250626.htm
  HTML page:      https://secwatch.observer/filing/0001999480-25-000053

License: Source filings: public domain (SEC EDGAR). Summaries (headline + bullets): CC-BY-4.0; attribute https://secwatch.observer