Exhibit 99.1
Arcellx Announces Oral Presentation for Its CART-ddBCMA Phase 1 Trial in Patients with Relapsed or
Refractory Multiple Myeloma at the 65th ASH Annual Meeting and Exposition
Abstract released today is from a June 2, 2023
data cut
Median duration of response, progression free survival, and overall survival rate not reached with median follow-up after CART-ddBCMA infusion of 22 months
A more recent data cut will be shared
during the oral presentation with a median follow-up of 26.5 months
Company to host a
live webcast event with an expert panel of clinicians
REDWOOD CITY, Calif., November 2,
2023 /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 that new clinical data from its Phase 1 study of CART-ddBCMA in patients with relapsed or refractory multiple myeloma will be presented at the 65th American Society of Hematology (ASH) Annual Meeting and Exposition taking place
December 9-12, 2023 in San Diego, California. The data in the ASH abstract published today is from a June 2, 2023 data cut. The oral presentation at ASH will be on Monday, December 11, 2023, at 5
p.m. PT and will include new data with a median follow-up of 26.5 months. The company will also have a medical affairs booth (#748) in Hall E of the San Diego Convention Center.
As detailed in the abstract (#1023), 38 patients were evaluable for efficacy and safety analysis as of the June 2, 2023 cutoff date, based on a median follow-up of 22 months following treatment. These evaluable patients comprised the dose escalation cohorts for the first dose level (100 (+/- 20) million CAR+ T cells, n=6) and the second dose level (300 (+/- 20)
million CAR+ T cells, n=6), and a dose expansion cohort at 100 (+/- 20) million CAR+ T cells (n=26). The median dose administered to patients in the first dose level and dose expansion cohorts was 115 million CAR+ T cells. All patients
evaluable for this analysis have poor prognostic factors with 38 of 38 (100%) patients triple-refractory, 26 of 38 (68%) penta-refractory, and 34 of 38 (89%) refractory to last-line of treatment by International Myeloma Working Group (IMWG)
criteria. Additionally, 9 of 38 patients (24%) patients had high tumor burden with >60% bone marrow plasma (BMPC) cells, 13 of 38 patients (34%) patients had extramedullary disease (EMD), and 11 of 38 (29%) patients had high-risk
cytogenetics (Del 17p, t(14;16), t(4;14)) at baseline. At baseline, 24 of 38 (63%) had at least one high risk clinical feature, defined as presence of EMD, BMPC >60% or B2M >5.5. All 38 patients had at least three prior lines of
therapy.
The interim CART-ddBCMA Phase 1 clinical results (June 2, 2023 cutoff date) demonstrate deep and durable responses in patients with poor
prognostic factors.