-- 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., Nov. 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.
All Patients:
Of the 38 evaluable patients with a median follow-up of 22
months
- 100% overall response rate (ORR) achieved in all patients per
IMWG criteria
- 29 of 38 evaluable patients achieved a complete response (CR)
or a stringent complete response (sCR) (> CR rate, 76%)
- 35 patients achieved a very good partial response or higher
(>VGPR rate, 92%)
Median duration of response, progression free survival (PFS),
and overall survival were not reached at the time of the
June 2, 2023 data cut because 25 of
38 (66%) evaluable patients had ongoing responses.
The Kaplan-Meier method estimated PFS rates for 6, 12, and 18
months were 92%, 74%, and 67% respectively. Durable responses were
also observed in patients with high-risk features (EMD, BMPC ≥60%,
or B2M ≥5.5 mg/L at baseline) and high-risk cytogenetics.
PFS rates at 6-, 12-, and 18 months by Kaplan-Meier method
were:
|
PFS Rates
(%)
|
|
6-month
|
12-month
|
18-month
|
All dosed
(n=38)
|
92.1
|
74.3
|
67.5
|
Age ≥65 years
(n=20)
|
95.0
|
84.4
|
78.4
|
Complete responders
(n=29)
|
96.4
|
88.8
|
84.6
|
High Risk Features*
(n=24)
|
91.7
|
73.3
|
68.1
|
Extramedullary Disease
(n=13)
|
92.3
|
64.6
|
64.6
|
High Risk Cytogenetics
(n=11)
|
81.8
|
70.1
|
70.1
|
*High risk features
defined as presence of EMD, BMPC ≥60, or B2M ≥5.5 mg/L. Note:
increased from prior presentation from 22 to 24 subjects as a
result of database update based on monitoring and query
resolution.
|
CART-ddBCMA dosed at RP2D (115 million (+/- 10) CAR+ T cells)
continues to be well-tolerated at the time of the data cut:
- Adverse events with CART-ddBCMA, including CRS and ICANS, were
manageable
- No tissue-targeted toxicities were observed
- No cases of delayed neurotoxicity events or parkinsonian
symptoms were observed
ASH Presentation Details:
Title: Phase 1
Study of CART-ddBCMA for the Treatment of Patients with Relapsed
and/or Refractory Multiple Myeloma: Results from at Least 1-Year
Follow-up in All Patients
Speaker: Matthew J. Frigault, M.D., Clinical
Director of the Cellular Therapy Service at Massachusetts General
Cancer Center, and Assistant Professor at Harvard Medical School
Session Name: 704. Cellular Immunotherapies: Early Phase
and Investigational Therapies: CAR-T Cell Therapies for Multiple
Myeloma and B Cell Lymphomas
Session Date: Monday, December 11,
2023
Session Time: 4:30 - 6:00 p.m.
PT (CART-ddBCMA oral presentation will be at 5 p.m.
PT)
Location: San Diego
Convention Center, Room 6A, San Diego,
California
Publication Number: 1023
Webcast Event:
Arcellx will host a live webcast event
with an expert panel of clinicians to discuss the clinical results
on Monday, December 11, 2023 at
8 p.m. PT. The event will be
accessible from Arcellx's website at www.arcellx.com in
the Investors section. A replay of the webcast will be archived and
available for 30 days following the event.
About Multiple Myeloma
Multiple Myeloma (MM) is a type of hematological cancer in which
diseased plasma cells proliferate and accumulate in the bone
marrow, crowding out healthy blood cells and causing bone lesions,
loss of bone density, and bone fractures. These abnormal plasma
cells also produce excessive quantities of an abnormal
immunoglobulin fragment, called a myeloma protein (M protein),
causing kidney damage and impairing the patient's immune function.
Multiple myeloma is the third most common hematological malignancy
in the United States and
Europe, representing approximately
10% of all hematological cancer cases and 20% of deaths due to
hematological malignancies. The median age of patients at diagnosis
is 69 years with one-third of patients diagnosed at an age of at
least 75 years. Because MM tends to afflict patients at an advanced
stage of life, patients often have multiple co-morbidities and
toxicities that can quickly escalate and become
life-endangering.
About CART-ddBCMA
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 or refractory multiple myeloma.
CART-ddBCMA is currently in a Phase 2 study. Arcellx's proprietary
binding domains are novel synthetic proteins designed to bind
specific therapeutic targets. CART-ddBCMA has been granted Fast
Track, Orphan Drug, and Regenerative Medicine Advanced Therapy
Designations by the U.S. Food and Drug Administration.
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 (rrMM) in a Phase 2 pivotal trial. 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, through two clinical-stage programs: a Phase 1
study of ACLX-001 for rrMM, initiated in the second quarter of
2022; and ACLX-002 in relapsed or refractory acute myeloid leukemia
and high-risk myelodysplastic syndrome, initiated in the fourth
quarter of 2022. For more information on Arcellx, please
visit www.arcellx.com. Follow Arcellx on X (formerly known as
Twitter) (@arcellx) and LinkedIn.
About Arcellx and Kite Pharma Collaboration Arcellx
and Kite, a Gilead Company, formed a global
strategic collaboration to co-develop and
co-commercialize Arcellx's CART-ddBCMA candidate for the treatment
of patients with relapsed or refractory multiple myeloma currently
in a pivotal Phase 2 study. Kite and Arcellx will jointly
advance and commercialize the CART-ddBCMA asset in the United States, and Kite will commercialize
the product outside the U.S.
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 plans for the
clinical development of its product candidates, including
anticipated announcements of additional data; Arcellx and Kite's
plans to advance and commercialize CART-ddBCMA; and the potential
impact of Arcellx's product candidates and platforms on patients
and cell therapy. 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 risks that may be found in the section
entitled Part II, Item 1A (Risk Factors) in the Quarterly Report on
Form 10-Q for the quarter ended June 30,
2023, filed with the Securities and Exchange Commission
(SEC) on August 14, 2023 and the
other documents that Arcellx may file from time to time with the
SEC. 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 Contact:
Myesha
Lacy
Arcellx, Inc.
ir@arcellx.com
510-418-2412
Media Contact
Andrea
Cohen
Sam Brown Inc.
andreacohen@sambrown.com
917-209-7163
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SOURCE Arcellx, Inc.