- Iomab-B led bone marrow transplant improved survival in
patients with high-risk relapsed or refractory acute myeloid
leukemia including those with a TP53 mutation
- Iomab-B safely delivered radiation to the target bone marrow at
greater amounts than achievable with total body irradiation while
sparing healthy non-target organs and enabled 100% access to bone
marrow transplant
- Novel linker technology supports Actinium's Antibody Radiation
Conjugate pipeline expansion in solid tumor indications
NEW
YORK, June 10, 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
highlighted data from multiple abstracts that were presented at the
2024 Society of Nuclear Medicine & Molecular Imaging (SNMMI)
Annual Meeting being held June 8 –
11, 2024, in Toronto, Canada. The
presentations featured results from the Phase 3 SIERRA trial of
Iomab-B, a CD45 targeting ARC with the Iodine-131 payload, intended
for conditioning to prepare patients with active relapsed or
refractory acute myeloid leukemia (r/r AML) for a potentially
curative bone marrow transplant (BMT). The Phase 3 SIERRA trial
enrolled 153 r/r AML patients. Iomab-B achieved the primary
endpoint of durable Complete Remission (dCR) with high statistical
significance (p<0.0001). Additionally, Actinium's novel linker
technology was highlighted in a presentation demonstrating high
tumor uptake and in vivo stability in preclinical models with
significantly lower kidney and liver uptake compared to standard
DOTA linkers.
Actinium's Iomab-B SNMMI presentations and highlights:
Survival Outcomes and Dosimetric Analysis of Iomab-B
(131I-apamistamab) Followed by Allogeneic Hematopoietic Cell
Transplant for Patients with TP53 Mutated Relapsed/Refractory
AML
- 37 patients (24%) enrolled on SIERRA had a TP53 mutation with
27 patients receiving Iomab-B (either through randomization or
cross over) and 10 patients on the control arm
- For patients with TP53 mutation who received Iomab-B, the
median OS was 5.49 months compared to a median 1.66 months in pts
who did not receive Iomab-B (HR=0.23; 95% CI [0.10, 0.52])
- These results support Iomab-B's differentiated mechanism
of action to overcome the negative impact of TP53 mutation
typically associated with a dismal prognosis in these patients
Exploratory Analysis of Bone Marrow Dosimetry from the
Randomized Phase 3 SIERRA Trial of Iomab-B (131I-apamistamab) Prior
to HCT in Relapsed/Refractory Acute Myeloid Leukemia
- Iomab-B safely delivers high doses of myeloablative targeted
radiation to the diseased bone marrow at greater amounts than what
would be achieved with total body irradiation
- Myeloablative doses were safely delivered to patients
irrespective of age, performance status and other metrics
- A median of 16Gy of radiation was delivered to the bone marrow
while normal healthy organs received significantly less exposure,
including the heart (2.6 Gy), lungs (2.5 Gy), small intestine
(2.4 Gy), stomach (3.6 Gy), kidneys (4.1 Gy) and the whole body
(3.3 Gy)
Mathematical Modeling of Exposure Measurements Following
High-Dose Targeted Therapy Using 131I-apamistamab: Analysis From
the Large Multicenter Phase III SIERRA Trial
- SIERRA patients received up to 1,030 mCi (range:
300-1,030) of Iodine-131 via Iomab-B
- Iomab-B is administered via a single infusion 12 days prior to
BMT
- Data from SIERRA show that the median time for patients to
reach the release criteria was 5 days, including in patients
receiving greater than 800 mCi
Actinium's Proprietary Linker Technology SNMMI presentation and
highlights:
Evaluation of novel DOTA-based linkers for improved targeted
radiotherapy delivery to solid tumors
- Novel linkers showed significantly lower kidney and liver
uptake compared to standard DOTA linkers
- SPECT/CT imaging showed high tumor uptake and in vivo stability
in preclinical models
- Successful design, efficient conjugation and pharmacological
properties support further advancement of these novel linkers
- Actinium has two wholly owned U.S. patents covering its
novel bifunctional linker technology with each having a patent term
extending into 2043 and a pending international patent
application
Sandesh Seth, Actinium's Chairman
and CEO, said, "At this year's SNMMI, we are proud to highlight
Actinium's broad ARC pipeline and capabilities. Building on our
leadership position in hematology focused ARCs through Iomab-B and
Actimab-A, we are excited to highlight the potential to treat
patients with high-risk relapsed or refractory AML and overcome
TP53 mutations or extensive prior therapy including Venetoclax.
Hematology represents an area with potential for significant growth
for the field of nuclear medicine and there is great excitement
from the community around our efforts. Consistent with our vision
to build a leading specialty radiotherapeutics company, we are also
eager to highlight our novel linker technology for solid tumor
ARCs. Finally, SNMMI provides the opportunity to showcase our
proprietary Actinium-225 cyclotron-based manufacturing technology
that has the potential to produce highly pure medical grade
Actinium-225 at a scale and cost that is not currently achievable,
which has been met with great enthusiasm given the industry
emphasis on Actinium-225 supply."
About the SNMMI Annual Meeting
The SNMMI Annual Meeting is recognized as the premier
educational, scientific, research, and networking event in nuclear
medicine and molecular imaging. The four-day event, taking place
each June, provides physicians, technologists, pharmacists,
laboratory professionals, and scientists with an in-depth view of
the latest research and development in the field as well as
providing insights into practical applications for the clinic.
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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