---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-26-218251"
form_type: "8-K"
ticker: "DFTX"
cik: "0001813814"
company_name: "Definium Therapeutics, Inc."
filed_at: "2026-05-12T12:15:16+00:00"
generated_at: "2026-05-12T12:22:02.777135+00:00"
event_type: "other_material"
sentiment: "neutral"
materiality_score: 0.4
calibrated_materiality_score: 0.4
confidence: "high"
source: SEC EDGAR
---

# Definium doses first patient in Phase 3 Ascend study of DT120 ODT for MDD; topline data expected 2027

## Summary
- First patient dosed in Ascend, second Phase 3 pivotal study of DT120 ODT (lysergide tartrate) for major depressive disorder.
- Primary endpoint: change from baseline in MADRS score at Week 6 for DT120 ODT 100 µg vs placebo.
- Study to enroll 175 participants in the U.S.; topline data from 12-week double-blind period anticipated in 2027.
- Ascend design aligns with Emerge Phase 3 and GAD trials; includes 40-week open-label extension and 2:1:2 randomization.
- 50 µg DT120 arm included to confound dose condition awareness and address functional unblinding concerns.

## SEC filing metadata
- accession: 0001193125-26-218251
- form_type: 8-K
- ticker: DFTX
- cik: 0001813814
- company_name: Definium Therapeutics, Inc.
- filed_at: 2026-05-12T12:15:16+00:00
- event_type: other_material
- sentiment: neutral
- materiality_score: 0.4
- calibrated_materiality_score: 0.4
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1813814/000119312526218251/0001193125-26-218251-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1813814/000119312526218251/dftx-20260512.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-26-218251
- JSON: https://secwatch.observer/filing/0001193125-26-218251.json
- Plain text: https://secwatch.observer/filing/0001193125-26-218251.txt

This AI-assisted summary is a reading aid. Review the linked SEC EDGAR filing before relying on any specific claim.