- Median
Overall Survival of 18.4 months with Actimab-A + CLAG-M in patients
with relapsed or refractory AML who received 1 or 2 lines of prior
therapy
- Mutation
agnostic potential of Actimab-A demonstrated by high rates of
Complete Remissions and Measurable Residual Disease Negativity in
patients with high-risk features including TP53 mutations and prior
Venetoclax treatment
- Actimab-A +
CLAG-M combination yielded deep and clinically meaningful responses
with expected and manageable safety profile supporting planned
pivotal Phase 2/3 trial
NEW
YORK, March 17, 2025 /PRNewswire/ -- Actinium
Pharmaceuticals, Inc. (NYSE AMERICAN: ATNM) (Actinium or the
Company), a pioneer in the development of targeted radiotherapies,
today announced that results from the clinical trial evaluating
Actimab-A in combination with the chemotherapy CLAG-M in patients
with relapsed/refractory acute myeloid leukemia (r/r AML) have been
published in the peer-reviewed journal Leukemia. The
publication highlights data including long-term survival outcomes
from two-year follow-up and better outcomes in high-risk patients.
Actimab-A is a novel targeted radiotherapeutic that uses the
Actinium-225 (Ac-225) isotope payload directed against CD33, a
marker expressed ubiquitously on AML blasts. The trial was
conducted at the Medical College of
Wisconsin (MCW) which has extensive experience treating
relapsed refractory AML patients with CLAG-M.
Actimab-A + CLAG-M Trial Data Highlights from
Publication:
- 18.4 month median Overall Survival (OS) in patients who
received 1 or 2 lines of prior therapy
- 52% of patients in the Actimab-A +CLAG-M trial had TP53
mutations, 56% had prior allogeneic stem cell transplant and 56% of
patients had prior Venetoclax therapy
- Actimab-A + CLAG-M outcomes compare favorably to the results
from historical data with CLAG-M alone in the pre-Venetoclax era
from MCW's study (median OS of 13.3 months). Typically, patients
who have failed Venetoclax treatment demonstrate median survival
between 2.4 – 4.6 months as reported in the literature and the
patients with a TP53 mutation even have more dismal survival
outcomes. Hence this data supports the use of Actimab-A plus CLAG-M
for these patients.
- Actimab-A + CLAG-M produced high rates of measurable residual
disease negativity (MRD-) including 75% across all patients, 83.3%
in patients with a TP53 mutation and 100% in patients with prior
Venetoclax therapy
- 71% of eligible patients received a bone marrow transplant
(BMT) and median OS in these patients was 24.05 months
Dr. Sameem Abedin, Associate
Professor of Medicine at the Medical College
of Wisconsin and Principal Investigator of the Actimab-A +
CLAG-M study said, "We are delighted that the Actimab-A + CLAG-M
results have been published in the peer-reviewed journal Leukemia.
Despite advancements in treatment, patients with r/r AML,
particularly those with high-risk features including TP53 mutations
and prior Venetoclax therapy like those in our study, continue to
have dismal outcomes and limited treatment options. We are excited
that the combination of Actimab-A and CLAG-M produced high response
rates with deep remissions including high rates of MRD negativity,
improving access to potentially curable BMT resulting in enhanced
survival outcomes. Importantly, we observed that responses were
retained in high-risk patients. We believe these results support
the utility of targeted radiotherapy for the treatment of AML and
its mutation agnostic mechanism of action. We look forward to the
initiation of the Phase 2/3 trial of Actimab-A + CLAG-M and further
advancing this potentially important therapeutic modality in this
patient population with a high unmet need."
Actinium has aligned with the FDA on a pivotal Phase 2/3
operationally seamless trial that will study Actimab-A + CLAG-M in
r/r AML patients. The trial will optimize the dose of Actimab-A in
combination with CLAG-M, that will be studied in the Phase 3
portion of the trial, which will be a randomized trial comparing
overall survival and other outcomes of patients with r/r AML
receiving Actimab-A + CLAG-M to CLAG-M alone. The trial is expected
to be initiated in 2025.
Sandesh Seth, Actinium's Chairman
and CEO, said, "There is significant momentum for Actimab-A with
the publication of these positive results in Leukemia and
the recent initiation of the frontline AML triplet combination with
Venetoclax and the hypomethylating agent ASTX-727 under our NCI
CRADA. Actinium is committed to addressing the needs of the over
100,000 patients with AML and MDS in the U.S. and Europe with Actimab-A to realize its
multi-billion-dollar market opportunity. Over the course of 2025,
we expect to generate additional clinical data further supporting
Actimab-A's mutation agnostic, backbone therapy potential for
radiation sensitive myeloid malignancies."
About Actinium Pharmaceuticals, Inc.
Actinium is a pioneer in the development of targeted
radiotherapies intended to meaningfully improve patient outcomes.
Actinium is advancing its lead product candidate Actimab-A, a CD33
targeting therapeutic, as potential backbone therapy in acute
myeloid leukemia (AML) and other myeloid malignancies leveraging
the mutation agnostic alpha-emitter radioisotope payload
Actinium-225 (Ac-225). Actimab-A has demonstrated potential
activity in relapsed and refractory acute myeloid leukemia (r/r
AML) patients in combination with the chemotherapy CLAG-M including
high rates of Complete Remissions (CR) including measurable
residual disease (MRD) negativity with improved survival outcomes
and is being advanced to a pivotal Phase 2/3 trial. In addition,
Actinium is engaged with the National Cancer Institute (NCI) under
the Cooperative Research and Development Agreement (CRADA) for
development of Actimab-A in AML and other myeloid malignancies. The
first clinical trial under the CRADA will evaluate the triplet
combination comprised of Actimab-A, Venetoclax (Abbvie/Roche) an
oral Bcl-2 inhibitor and ASTX-727 (Taiho Oncology, an Otsuka
holdings company) a novel oral hypomethylating agent (HMA) in
frontline acute myeloid leukemia (AML) patients. Iomab-ACT,
Actinium's next generation conditioning candidate, is being
developed with the goal of improving patient access and outcomes
for potentially curative cell and gene therapies. Iomab-B is an
induction and conditioning agent prior to bone marrow transplant in
patients with r/r AML, which Actinium is seeking a potential
strategic partner for in the U.S. In addition, the company's
R&D efforts are primarily focused on advancing several
preclinical programs for solid tumor indications. Actinium holds
230 patents and patent applications including several patents
related to the manufacture of the isotope Ac-225 in a
cyclotron.
For more information, please
visit: https://www.actiniumpharma.com/
Forward-Looking Statements
This press release may contain projections or other
"forward-looking statements" within the meaning of the
"safe-harbor" provisions of the private securities litigation
reform act of 1995 regarding future events or the future financial
performance of the Company which the Company undertakes no
obligation to update. These statements are based on management's
current expectations and are subject to risks and uncertainties
that may cause actual results to differ materially from the
anticipated or estimated future results, including the risks and
uncertainties associated with preliminary study results varying
from final results, estimates of potential markets for drugs under
development, clinical trials, actions by the FDA and other
governmental agencies, regulatory clearances, responses to
regulatory matters, the market demand for and acceptance of
Actinium's products and services, performance of clinical research
organizations and other risks detailed from time to time in
Actinium's filings with the Securities and Exchange Commission (the
"SEC"), including without limitation its most recent annual report
on form 10-K, subsequent quarterly reports on Forms 10-Q and Forms
8-K, each as amended and supplemented from time to time.
Investors:
investorrelations@actiniumpharma.com
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