Arcellx Presents Pre-Clinical Data for ACLX-002, a Novel CD123-targeted Universal CAR-T Cell Therapy for Relapsed or Refractory Acute Myeloid Leukemia at the American Association for Cancer Research Annual Meeting

-- ACLX-002 completely regresses multiple cell line and patient-derived AML xenografts --

-- Company plans to initiate ACLX-002 Phase 1 clinical trial in AML/MDS in 2H'22 --

FOSTER CITY, Calif., April 8, 2022 /PRNewswire/ -- Arcellx, Inc. (NASDAQ: ACLX), a biotechnology company reimagining cell therapy through the development of innovative immunotherapies for patients with cancer and other incurable diseases, today announced the presentation of preclinical data utilizing its novel ARC-SparX platform for ACLX-002, a CD123-targeted universal CAR-T cell therapy for relapsed or refractory Acute Myelogenous Leukemia (AML) and high-risk myelodysplastic syndrome (MDS). The data show that ACLX-002 completely regressed disseminated MOLM14 and MV4-11 tumors in a schedule and dose-dependent manner without the aid of alloreactivity and performs similarly to a traditional CD123-targeting D-domain based CAR. Additionally, ACLX-002 completely regresses multiple cell line and patient-derived AML xenografts.

"There are limited treatment options for AML and MDS patients as heterogeneity is known to be a major challenge for targeted therapeutics in this patient population," said Rami Elghandour, Arcellx's chairman and chief executive officer. "Our ARC-SparX platform is designed to allow for controllability and adaptability, to potentially reduce toxicities that are often associated with serious dose-limiting adverse events and to overcome tumor heterogeneity. These ACLX-002 preclinical data provide the scientific rationale to move forward with initiating a Phase 1 clinical trial and our ambition to deliver a meaningful treatment option for these patients. We look forward to starting this study in the second half of this year." 

The data are being presented at the American Association of Cancer Research (AACR) Annual Meeting taking place April 8-13, 2022. Presentation details are as follows:

The poster can be accessed through the AACR Annual Meeting program or the company's corporate website www.arcellx.com/pipeline-focus-area/#scientific-publications

About the ARC-SparX Platform Technology
The ARC-SparX platform is designed to allow for controllability and adaptability, to potentially reduce toxicities that are often associated with serious dose-limiting adverse events and to overcome tumor heterogeneity. It is a modular therapy which utilizes a universal ARC-T cell combined with an off the shelf SparX protein to separate the tumor-recognition and tumor-killing functions. SparX (soluble protein antigen-receptor X-linkers) proteins utilize our D-Domain technology engineered to recognize antigens on the surface of diseased cells and flags those cells for detection by the ARC-T (Antigen Receptor Complex-T) cells. ARC-T cells express a D-Domain-based CAR engineered to specifically recognize a unique TAG in the SparX protein. ARC-T cells are dosed separately and only activated to kill the target cell when they encounter a SparX protein bound to the target antigen thus are controlled through SparX dose modulation. Arcellx has developed a collection of SparX proteins that bind different antigens on the surface of diseased cells. Multiple SparX proteins with different antigen specificity can be administered to potentially address antigen heterogeneity or antigen escape that contribute to relapsed and refractory disease.

About Arcellx, Inc.
Arcellx, Inc. is a clinical-stage biotechnology company reimagining cell therapy by engineering innovative immunotherapies for patients with cancer and other incurable diseases. Arcellx believes that cell therapies are one of the forward pillars of medicine and Arcellx's mission is to advance humanity by developing cell therapies that are safer, more effective, and more broadly accessible. Arcellx's lead product candidate, CART-ddBCMA, is being developed for the treatment of relapsed or refractory multiple myeloma (r/r MM) in an ongoing Phase 1 study. CART-ddBCMA has been granted Fast Track, Orphan Drug, and Regenerative Medicine Advanced Therapy designations by the U.S. Food and Drug Administration.

Arcellx is also advancing its dosable and controllable CAR-T therapy, ARC-SparX, into the clinic through two programs: ACLX-001 in r/r MM and ACLX-002 in relapsed or refractory acute myeloid leukemia and high-risk myelodysplastic syndrome. Visit www.arcellx.com for more information.

Forward-looking statements
This press release contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, and Section 21E of the Securities Exchange Act of 1934, as amended. All statements in this press release that are not purely historical are forward-looking statements, including Arcellx's expectations regarding the timing of clinical trials for its product candidates. The forward-looking statements contained herein are based upon Arcellx's current expectations and involve assumptions that may never materialize or may prove to be incorrect. These forward-looking statements are neither promises nor guarantees and are subject to a variety of risks and uncertainties, including those set forth in Part I, Item 1A (Risk Factors) of Arcellx's Annual Report on Form 10-K and in other reports, including Quarterly Reports on Form 10-Q and Current Reports on Form 8-K, that Arcellx may file from time to time with the Securities and Exchange Commission. These forward-looking statements are made as of the date of this press release, and Arcellx assumes no obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law.

Investor and Media Contact:
Myesha Lacy
Arcellx, Inc.
[email protected]

SOURCE Arcellx, Inc