---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-25-244262"
form_type: "8-K"
ticker: "QTTB"
cik: "0001661998"
company_name: "Q32 Bio Inc."
filed_at: "2025-10-21T23:59:59+00:00"
generated_at: "2026-05-17T03:02:33.974522+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.65
calibrated_materiality_score: 0.65
confidence: "high"
source: SEC EDGAR
---

# Q32 Bio completes enrollment in Part B of SIGNAL-AA Phase 2a trial; exceeds target to 33 patients

## Summary
- Enrollment completed in Part B of SIGNAL-AA Phase 2a trial for bempikibart in severe/very severe alopecia areata.
- Enrollment exceeded initial target of ~20 patients, total 33 patients enrolled due to patient demand.
- Part B includes loading regimen (200mg weekly x4 then every other week) with 36-week dosing; topline data expected mid-2026.
- Preliminary PK data shows steady state achieved earlier with loading regimen; signs of clinical activity observed among early patients.
- Company plans to advance to pivotal trials pending Part B results.

## SEC filing metadata
- accession: 0001193125-25-244262
- form_type: 8-K
- ticker: QTTB
- cik: 0001661998
- company_name: Q32 Bio Inc.
- filed_at: 2025-10-21T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.65
- calibrated_materiality_score: 0.65
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1661998/000119312525244262/0001193125-25-244262-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1661998/000119312525244262/d43495d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-25-244262
- JSON: https://secwatch.observer/filing/0001193125-25-244262.json
- Plain text: https://secwatch.observer/filing/0001193125-25-244262.txt

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