---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-23-268942"
form_type: "8-K"
ticker: "ACLX"
cik: "0001786205"
company_name: "Arcellx, Inc."
filed_at: "2023-11-02T23:59:59+00:00"
generated_at: "2026-06-09T00:44:17.602439+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.8
calibrated_materiality_score: 0.8
confidence: "high"
source: SEC EDGAR
---

# Arcellx reports 100% ORR, 76% CR rate in Phase 1 CART-ddBCMA trial; median follow-up 22 mo

## Summary
- Overall response rate 100% per IMWG criteria; 29/38 patients (76%) achieved CR or sCR.
- Median duration of response, PFS, and OS not reached at 22 months median follow-up.
- 6-, 12-, 18-month PFS rates by KM: 92%, 74%, 67%. Durable in high-risk subgroups.
- All 38 patients triple-refractory; 68% penta-refractory; 89% refractory to last line.
- CART-ddBCMA well tolerated; manageable CRS/ICANS, no delayed neurotoxicity or parkinsonism.

## SEC filing metadata
- accession: 0001193125-23-268942
- form_type: 8-K
- ticker: ACLX
- cik: 0001786205
- company_name: Arcellx, Inc.
- filed_at: 2023-11-02T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.8
- calibrated_materiality_score: 0.8
- confidence: high
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1786205/000119312523268942/0001193125-23-268942-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1786205/000119312523268942/d572316d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-23-268942
- JSON: https://secwatch.observer/filing/0001193125-23-268942.json
- Plain text: https://secwatch.observer/filing/0001193125-23-268942.txt

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