---
schema_version: "secwatch.filing_event.v1"
accession: "0001558370-21-012911"
form_type: "8-K"
ticker: "OMER"
cik: "0001285819"
company_name: "OMEROS CORP"
filed_at: "2021-10-01T23:59:59+00:00"
generated_at: "2026-06-28T23:48:36.362295+00:00"
event_type: "regulatory"
sentiment: "negative"
materiality_score: 0.9
calibrated_materiality_score: 0.9
confidence: "high"
source: SEC EDGAR
---

# Omeros receives FDA deficiency notice for narsoplimab BLA; PDUFA date expected to be missed

## Summary
- FDA identified deficiencies in narsoplimab BLA for HSCT-TMA, precluding labeling/post-marketing discussions.
- Resolution not expected by Oct 17, 2021 PDUFA target action date; FDA expressed intent to work with Omeros.
- No specific deficiencies disclosed; Omeros evaluating next steps for HSCT-TMA, a lethal condition with no approved therapy.
- Narsoplimab has Breakthrough Therapy and Orphan designations; first BLA submitted for HSCT-TMA.

## SEC filing metadata
- accession: 0001558370-21-012911
- form_type: 8-K
- ticker: OMER
- cik: 0001285819
- company_name: OMEROS CORP
- filed_at: 2021-10-01T23:59:59+00:00
- event_type: regulatory
- sentiment: negative
- materiality_score: 0.9
- calibrated_materiality_score: 0.9
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1285819/000155837021012911/0001558370-21-012911-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1285819/000155837021012911/omer-20211001x8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001558370-21-012911
- JSON: https://secwatch.observer/filing/0001558370-21-012911.json
- Plain text: https://secwatch.observer/filing/0001558370-21-012911.txt

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