---
schema_version: "secwatch.filing_event.v1"
accession: "0001125345-26-000009"
form_type: "8-K"
ticker: "MGNX"
cik: "0001125345"
company_name: "MACROGENICS INC"
filed_at: "2026-02-24T23:59:59+00:00"
generated_at: "2026-05-16T00:39:10.289740+00:00"
event_type: "regulatory"
sentiment: "negative"
materiality_score: 0.85
calibrated_materiality_score: 0.85
confidence: "high"
source: SEC EDGAR
---

# FDA partial clinical hold on MacroGenics' Phase 2 LINNET study of lorigerlimab after severe safety events

## Summary
- Partial hold halts new enrollment; current participants may continue receiving lorigerlimab.
- Safety events across 4 patients: Grade 4 thrombocytopenia (2), myocarditis (1), neutropenia with septic shock (1) leading to 1 death (Grade 5).
- 41 patients dosed at 6 mg/kg every 3 weeks in platinum-resistant ovarian and clear cell gynecologic cancer cohorts.
- MacroGenics commits to working with FDA to resolve the hold and resume enrollment.

## SEC filing metadata
- accession: 0001125345-26-000009
- form_type: 8-K
- ticker: MGNX
- cik: 0001125345
- company_name: MACROGENICS INC
- filed_at: 2026-02-24T23:59:59+00:00
- event_type: regulatory
- sentiment: negative
- materiality_score: 0.85
- calibrated_materiality_score: 0.85
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1125345/000112534526000009/0001125345-26-000009-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1125345/000112534526000009/mgnx-20260223.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001125345-26-000009
- JSON: https://secwatch.observer/filing/0001125345-26-000009.json
- Plain text: https://secwatch.observer/filing/0001125345-26-000009.txt

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