---
schema_version: "secwatch.filing_event.v1"
accession: "0001104659-26-049733"
form_type: "8-K"
ticker: "ACRS"
cik: "0001557746"
company_name: "Aclaris Therapeutics, Inc."
filed_at: "2026-04-28T23:59:59+00:00"
generated_at: "2026-05-15T02:51:00.984252+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.85
calibrated_materiality_score: 0.85
confidence: "high"
source: SEC EDGAR
---

# Aclaris reports positive Phase 1a data for ATI-052 (half-life ~45 days) and picks lichen planus for ATI-2138

## Summary
- ATI-052 half-life ~45 days; complete inhibition of CCL17/TARC sustained at least 20 weeks post-dose.
- Phase 1a ATI-052 well tolerated; no conjunctivitis or safety signals; dose proportional PK observed.
- Phase 1b trials in asthma and atopic dermatitis enrolling; top line results expected H2 2026.
- Phase 2b for ATI-052 targeting asthma planned for Q4 2026; Phase 2b ATI-2138 in lichen planus starts H2 2026.
- ATI-2138 is a potential first-in-class oral ITK/JAK3 inhibitor addressing pathogenic T cells; no FDA-approved LP therapies.

## SEC filing metadata
- accession: 0001104659-26-049733
- form_type: 8-K
- ticker: ACRS
- cik: 0001557746
- company_name: Aclaris Therapeutics, Inc.
- filed_at: 2026-04-28T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.85
- calibrated_materiality_score: 0.85
- confidence: high
- sec_items: 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1557746/000110465926049733/0001104659-26-049733-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1557746/000110465926049733/acrs-20260428x8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001104659-26-049733
- JSON: https://secwatch.observer/filing/0001104659-26-049733.json
- Plain text: https://secwatch.observer/filing/0001104659-26-049733.txt

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