---
schema_version: "secwatch.filing_event.v1"
accession: "0001193125-24-275844"
form_type: "8-K"
ticker: "ACLX"
cik: "0001786205"
company_name: "Arcellx, Inc."
filed_at: "2024-12-12T23:59:59+00:00"
generated_at: "2026-05-29T04:12:46.660404+00:00"
event_type: "other_material"
sentiment: "positive"
materiality_score: 0.7
calibrated_materiality_score: 0.7
confidence: "medium"
source: SEC EDGAR
---

# Arcellx reports positive Phase 2 anito-cel data for relapsed/refractory multiple myeloma at ASH 2024

## Summary
- Hosted investor webcast at ASH highlighting new positive data from Phase 2 pivotal iMMagine-1 study of anito-cel.
- Study evaluates anitocabtagene autoleucel in patients with relapsed or refractory multiple myeloma.
- Filing notes data as positive but does not disclose specific efficacy or safety numbers.
- Corporate presentation attached as Exhibit 99.1 provides further details not included in this summary.

## SEC filing metadata
- accession: 0001193125-24-275844
- form_type: 8-K
- ticker: ACLX
- cik: 0001786205
- company_name: Arcellx, Inc.
- filed_at: 2024-12-12T23:59:59+00:00
- event_type: other_material
- sentiment: positive
- materiality_score: 0.7
- calibrated_materiality_score: 0.7
- confidence: medium
- sec_items: 8.01, 9.01
- EDGAR index: https://www.sec.gov/Archives/edgar/data/1786205/000119312524275844/0001193125-24-275844-index.htm
- EDGAR primary document: https://www.sec.gov/Archives/edgar/data/1786205/000119312524275844/d844330d8k.htm

## Machine-readable alternates
- HTML: https://secwatch.observer/filing/0001193125-24-275844
- JSON: https://secwatch.observer/filing/0001193125-24-275844.json
- Plain text: https://secwatch.observer/filing/0001193125-24-275844.txt

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