Preclinical Data of Arcellx’s Novel Synthetic CAR-T Binding Domain Presented at the 2021 ASGCT Annual Meeting and the 2021 PEGS Summit

Novel synthetic binding domain used in CART-ddBCMA demonstrates potent anti-tumor activity

Results underpin Arcellx’s ongoing first-in-human Phase 1 CART-ddBCMA trial in patients with relapsed and refractory multiple myeloma

GAITHERSBURG, Md., May 13, 2021 (GLOBE NEWSWIRE) – – Arcellx, a privately held clinical-stage biopharmaceutical company, today announced the presentation of preclinical data of CART-ddBCMA, Arcellx’s BCMA-specific CAR-modified T-cell therapy, at the 2021 American Society of Gene & Cell Therapy (ASGCT) Annual Meeting and at the 2021 Protein Engineering & Cell Therapy Summit (PEGS). The presentations detail the novel synthetic binding domain of CART-ddBCMA and its ability to generate potent anti-tumor activity in vitro and in vivo against BCMA-positive cancer cells.

CART-ddBCMA is currently being investigated in an ongoing Phase 1 trial in patients with relapsed and refractory multiple myeloma. Arcellx announced positive initial clinical results from the first six patients in the trial at the 2020 American Society of Hematology (ASH) Annual Meeting. The data presented at ASH showed all six multiple myeloma patients responded per the IMWG criteria, with four of those patients achieving stringent complete response, indicating the confirmed disappearance of all signs of cancer and absence of molecular or cytogenetic markers of disease. The therapy was well-tolerated, and CAR-T related toxicities resolved rapidly.

Details of the presentations are as follows:

2021 American Society of Gene & Cell Therapy Annual Meeting
Title: Design and Demonstration of Potent In Vitro and In Vivo Activity for CART-ddBCMA, a BCMA-Targeted CAR-T Cell Therapy Incorporating a Non-scFv Binding Domain
Authors: Janine M Buonato, et al.
Session Date/Time: Wednesday, May 12, 2021 at 6:00 p.m. ET
Session Title: Targeted Gene and Cell Therapy for Cancer
Abstract Number: 115

2021 Protein Engineering & Cell Therapy Summit
Title: D Domains: A de novo Scaffold for the Development of Targeted Therapeutics
Authors: David LaFleur, et al.
Session Date/Time: Thursday, May 13, 2021 at 9:40 a.m. ET
Session Title: Engineering Antibodies

Both presentations are available online on the ASGCT and PEGS annual meeting websites. They are also available 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
[email protected]


Alan Lada
Solebury Trout
[email protected]