---
schema_version: "secwatch.filing_event.v1"
accession: "0001140361-26-010651"
form_type: "8-K"
ticker: "INSM"
cik: "0001104506"
company_name: "INSMED Inc"
filed_at: "2026-03-23T23:59:59+00:00"
generated_at: "2026-05-15T09:19:50.941990+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.9
calibrated_materiality_score: 0.9
confidence: "high"
source: SEC EDGAR
---

# Insmed Reports Positive Topline Results from Phase 3b ENCORE Study of ARIKAYCE in MAC Lung Disease

## Summary
- Primary endpoint met: change from baseline in Respiratory Symptom Score at Month 13 showed 17.77 vs 14.66 points (p=0.0299).
- All multiplicity-controlled secondary culture conversion endpoints met: 87.8% vs 57.0% by Month 6, 84.7% vs 61.3% by Month 12 (p<0.0001).
- Durable culture conversion at Month 15: 76.2% vs 47.6% (p<0.0001).
- Plans to file sNDA in U.S. and submit data to PMDA in Japan in H2 2026 for potential label expansion.
- Safety profile consistent with known ARIKAYCE profile; no new safety signals observed.

## SEC filing metadata
- accession: 0001140361-26-010651
- form_type: 8-K
- ticker: INSM
- cik: 0001104506
- company_name: INSMED Inc
- filed_at: 2026-03-23T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.9
- calibrated_materiality_score: 0.9
- confidence: high
- sec_items: 7.01, 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1104506/000114036126010651/0001140361-26-010651-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1104506/000114036126010651/ef20068516_8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001140361-26-010651
- JSON: https://secwatch.observer/filing/0001140361-26-010651.json
- Plain text: https://secwatch.observer/filing/0001140361-26-010651.txt

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