- Actimab-A enhances dose-dependent acute myeloid
leukemia cell death in KMT2A sensitive acute myeloid leukemia
blasts in combination with leading menin inhibitors
- Combination with leading menin inhibitor
demonstrates acute myeloid leukemia cell death and significant
tumor elimination not achieved with monotherapy
- Menin combination expands backbone potential of
Actimab-A in acute myeloid leukemia that already includes
chemotherapy, venetoclax and FLT3 inhibitors
NEW
YORK, June 17, 2024 /PRNewswire/ -- Actinium
Pharmaceuticals, Inc. (NYSE AMERICAN: ATNM) (Actinium or the
Company), a leader in the development of Antibody Radiation
Conjugates (ARCs) and other targeted radiotherapies, today
announced that an abstract detailing the first ever preclinical
data from the combination of menin inhibitors with Actinium's ARC
Actimab-A in acute myeloid leukemia (AML) models was presented at
the 2024 European Hematology Association (EHA) Congress held
June 13 – 16, 2024, in Madrid, Spain. Actinium studied Actimab-A in
combination with the leading menin inhibitors, revumenib (Syndax
Pharmaceuticals, Inc.) and ziftomenib (Kura Oncology, Inc.), which
are being developed for patients with KMT2A rearrangements and NMP1
mutations, which are present in approximately 10% and 30% of AML
patients, respectively.
Actimab-A + Menin inhibitor combination results include:
- Actimab-A as a single agent showed potent in vitro AML cell
killing activity in both MV-4-11 and MOLM-13 KMT2A mutant cell
lines, compared to the non-radio conjugated CD33 antibody
lintuzumab (p<0.0001)
- Actimab-A enhanced AML cell death when combined with both
revumenib and ziftomenib at all dose levels in difficult to treat
KMT2A mutant AML
- The combination of Actimab-A with leading menin inhibitors
triggered an acute increase in AML necrosis and cell death in vivo
relative to single agent therapy within 72 hours of dosing
- Anti-tumor effect was significantly potentiated and prolonged
when combining Actimab-A with a leading menin inhibitor compared to
monotherapies in xenograft leukemia models in vivo (p<0.0024
Actimab-A + menin) as shown in the exhibit below
The Actimab-A + Menin Inhibitor combination presentation can be
accessed on the investor relations page of Actinium's
website here.
Actimab-A targets CD33, a marker expressed ubiquitously in
patients with AML, and is conjugated with the alpha-partible
payload Actinium-225. The broad expression of CD33 and the
differentiated mutation agnostic cell-killing mechanism of targeted
radiotherapy make Actimab-A broadly applicable for combinations
with chemotherapy, targeted agents including venetoclax, FLT3 and
menin inhibitors, immunotherapies and cellular therapies supporting
its potential backbone therapy profile across the AML patient
treatment journey.
Sandesh Seth, Actinium's Chairman
and CEO, said, "Combining with menin inhibitors is an exciting
expansion of the already broad potential of Actimab-A in AML.
Across single agent and combination studies, Actimab-A has produced
high rates of response, MRD negativity and improved survival in
high-risk, relapsed and refractory patients including those with a
TP53 mutation and venetoclax failures. The broad expression of CD33
in AML coupled with the potency of Actinium-225 make Actimab-A an
ideal agent for treating radiation sensitive AML. We are encouraged
by this highly promising initial data and the synergistic potential
of Actimab-A with menin inhibitors, which has broad potential
across the AML treatment continuum including frontline, maintenance
and relapsed/refractory settings. We are eager to continue to study
this combination and generate additional data that could support
advancing into clinical studies of Actimab-A with menin
inhibitors."
Menin inhibitors are a class of drug candidates being developed
for patients with AML that have a rearrangement of the KMT2A gene,
previously known as the mixed-lineage leukemia (MLL) or mutation of
the NPM1 gene. There are multiple menin inhibitors in development
for these patients with revumenib (Syndax Pharmaceuticals, Inc.)
being most advanced having a PDUFA data of September 2024 and ziftomenib (Kura Oncology,
Inc.) enrolling patients in a registration Phase 2 trial. Multiple
menin inhibitors are being studied in Phase 1 clinical trials by
companies including Johnson & Johnson, Sumitomo Pharma Co.,
Ltd., Hutchmed, Biomea Fusion, Inc. and BioNova Pharmaceuticals Pvt
Ltd.
About Actinium Pharmaceuticals, Inc.
Actinium develops targeted radiotherapies to meaningfully
improve survival for people who have failed existing oncology
therapies. Advanced pipeline candidates Iomab-B (pre-BLA & MAA
(EU)), an induction and conditioning agent prior to bone marrow
transplant, and Actimab-A (National Cancer Institute CRADA pivotal
development path), a therapeutic agent, have demonstrated potential
to extend survival outcomes for people with relapsed and refractory
acute myeloid leukemia. Actinium plans to advance Iomab-B for other
blood cancers and next generation conditioning candidate Iomab-ACT
to improve cell and gene therapy outcomes. Actinium holds more than
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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SOURCE Actinium Pharmaceuticals, Inc.