---
schema_version: "secwatch.filing_event.v1"
accession: "0001125345-24-000151"
form_type: "8-K"
ticker: "MGNX"
cik: "0001125345"
company_name: "MACROGENICS INC"
filed_at: "2024-09-16T23:59:59+00:00"
generated_at: "2026-05-31T04:29:08.745693+00:00"
event_type: "other_material"
sentiment: "neutral"
materiality_score: 0.7
calibrated_materiality_score: 0.7
confidence: "high"
source: SEC EDGAR
---

# MacroGenics TAMARACK Phase 2 data: 6-month rPFS 69-70%, ORR up to 40.6%, but 8 treatment-related deaths

## Summary
- 6-month radiographic PFS rate 69% (2.0 mg/kg) and 70% (2.7 mg/kg); median rPFS ~8.5 and 7.5 months (immature).
- Confirmed ORR 20.0% (2.0 mg/kg) and 40.6% (2.7 mg/kg) among RECIST-evaluable patients.
- Median 6 doses received (range 1-12); 25.6% (2.0 mg/kg) and 18.6% (2.7 mg/kg) remained on drug at data cutoff.
- Grade ≥3 TEAEs: 65.6% (2.0 mg/kg) and 62.8% (2.7 mg/kg); discontinuation rates 25.6% and 38.4%.
- 8 fatal treatment-related AEs (5 in 2.0 mg/kg, 3 in 2.7 mg/kg) including pneumonitis and cardiac events.

## SEC filing metadata
- accession: 0001125345-24-000151
- form_type: 8-K
- ticker: MGNX
- cik: 0001125345
- company_name: MACROGENICS INC
- filed_at: 2024-09-16T23:59:59+00:00
- event_type: other_material
- sentiment: neutral
- materiality_score: 0.7
- calibrated_materiality_score: 0.7
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1125345/000112534524000151/0001125345-24-000151-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1125345/000112534524000151/mgnx-20240916.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001125345-24-000151
- JSON: https://secwatch.observer/filing/0001125345-24-000151.json
- Plain text: https://secwatch.observer/filing/0001125345-24-000151.txt

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