---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-26-407823"
form_type: "8-K"
ticker: "TECX"
cik: "0001681087"
company_name: "Tectonic Therapeutic, Inc."
filed_at: "2026-09-29T21:19:22+00:00"
generated_at: "2026-10-12T13:53:50.492936+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.8
calibrated_materiality_score: 0.8
confidence: "high"
source: SEC EDGAR
---

# Tectonic reports favorable TX2100 Phase 1a safety results and FDA Fast Track for HHT

## Summary
- TX2100 Phase 1a single ascending doses were generally safe and well-tolerated across all six planned cohorts; no deaths, SAEs, or severe TEAEs at any dose.
- FDA granted TX2100 Fast Track designation for hereditary hemorrhagic telangiectasia (HHT) and cleared the IND for a U.S. Phase 1b trial in HHT patients.
- Tectonic plans an open-label Phase 1b trial in hematologic-support dependent HHT by year-end 2026 and a placebo-controlled Phase 2 in moderate-to-severe HHT in early 2027.
- The Phase 1a trial enrolled 48 healthy adults ages 18-55 across six cohorts of eight, randomized 3:1 to TX2100 or placebo; Part B multiple-dose enrollment is complete.
- PK results showed target-mediated drug disposition at low concentrations, supporting once weekly or every other week subcutaneous dosing; detailed data to be presented Oct. 12-16, 2026.

## SEC filing metadata
- accession: 0001193125-26-407823
- form_type: 8-K
- ticker: TECX
- cik: 0001681087
- company_name: Tectonic Therapeutic, Inc.
- filed_at: 2026-09-29T21:19:22+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.8
- calibrated_materiality_score: 0.8
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1681087/000119312526407823/0001193125-26-407823-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1681087/000119312526407823/d20857d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-26-407823
- JSON: https://secwatch.observer/filing/0001193125-26-407823.json
- Plain text: https://secwatch.observer/filing/0001193125-26-407823.txt

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