Arcellx Announces Presentation of Positive Clinical Results from Ongoing Phase 1 Study of CART-ddBCMA at the 2021 ASCO Annual Meeting

GAITHERSBURG, Md., June 4, 2021 (GLOBE NEWSWIRE) – – Arcellx, a privately held clinical-stage biopharmaceutical company, announced the presentation of positive clinical data from the first 12 evaluable patients treated in the ongoing Phase 1 study of CART-ddBCMA for the treatment of patients with relapsed and refractory multiple myeloma. The results were presented today at the 2021 American Society of Clinical Oncology (ASCO) Annual Meeting.

Clinical Presentation Details

Title: Phase 1 Study of CART-ddBCMA, a CAR-T therapy utilizing a novel synthetic binding domain for the treatment of subjects with relapsed and refractory multiple myeloma
Lead Author: Matthew J. Frigault, M.D., Massachusetts General Hospital; Harvard Medical School
Session Title:  Hematologic Malignancies—Plasma Cell Dyscrasia
Abstract Number: 8015

CART-ddBCMA Clinical Results Summary

As previously announced, as of the April 14, 2021 data cutoff:

  • 12 of 12 patients achieved responses per IMWG criteria (median follow-up of 197 days; (Min – Max) 29-449 days)
    • 5 patients achieved stringent complete responses (sCR)
    • 1 patient achieved a complete response (CR)
    • 3 patients achieved very good partial responses (VGPR)
    • 3 patients achieved partial responses (PR)
  • One patient achieved VGPR despite prior progression on BCMA-targeted therapy
  • Responses in 11 patients are ongoing, with evidence that responses deepen over time

All patients enrolled in the study have poor prognostic factors with 10 of 12 patients penta-refractory and all 12 patients having had at least three prior treatments.

The full presentation is available online in the ASCO Annual Meeting Library and within the Scientific Presentations section of the Arcellx website under News & Presentations at


CART-ddBCMA is Arcellx’s BCMA-specific CAR-modified T-cell therapy utilizing the company’s novel BCMA-targeting binding domain for the treatment of patients with relapsed and refractory multiple myeloma that is currently in a Phase 1 study. Arcellx’s proprietary binding domains are novel synthetic proteins engineered for reduced immunogenicity and designed to bind specific therapeutic targets. CART-ddBCMA has been granted Fast Track Designation and Orphan Drug Designation by the U.S. Food and Drug Administration. Additional information about the trial can be found at

About Arcellx, Inc.

Arcellx is a clinical-stage biopharmaceutical company developing adaptive and controllable cell therapies for the treatment of patients with cancer and autoimmune diseases. The Arcellx vision is to utilize our novel proprietary platform to bring superior cell therapies to more patients through the care of academic and community practices worldwide. More information can be found at


Zara Lockshin
Solebury Trout
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Alan Lada
Solebury Trout
[email protected]