Actinium Activates Radiation Inside the Body for Target Conditioning of Cancer Cells

The following post was written and/or published as a collaboration between Benzinga’s in-house sponsored content team and a financial partner of Benzinga.

Actinium Pharmaceuticals Inc. ATNM, a clinical-stage biopharmaceutical company, is developing antibody radiation-conjugates (ARCs) to combine the targeting ability of antibodies with the cell-killing ability of radiation. The Company is a leader in the targeted radiotherapy field for cancer patients who can’t tolerate chemotherapy and radiation. Actinium’s lead asset, Iomab-B, is currently being studied in a pivotal Phase 3 clinical trial.

Standing out in the Field of Target Conditioning

What makes Actinium unique is in its novel approach to treatment options for cancer patients. According to the National Cancer Institute (NCI) a conditioning regimen may include chemotherapy, monoclonal antibody therapy and radiation to the entire body. It supports the patient's body to make room in the bone marrow for new blood stem cells to grow, helps prevent the body from rejecting the transplanted cells and assists with killing any cancerous cells. Actinium’s targeted radiotherapies are intended to be focused missiles that hit cancer directly as opposed to a broader chemoradiation therapy that can hit many other areas that do not need to be attacked with such harsh treatments. 

Among its competitors, Actinium remains the only company with a pivotal Phase 3 trial for a targeting conditioning agent and the only anti-CD45 ARC in clinical development.

Multiphase Clinical Trials and the Success of Iomab-B

In the ongoing Phase 3 SIERRA trial, Actinium’s lead asset lomab-B acts as an induction and conditioning agent in patients over the age of 55 with relapsed or refractory acute myeloid leukemia (AML) prior to receiving a bone marrow transplant, also known as a hematopoietic stem cell transplant.

This multicenter trial is being conducted at over 20 leading transplant centers in the U.S., including MD Anderson, Memorial Sloan Kettering and Mayo Clinic. 

“Of all patients who received a therapeutic dose of Iomab-B, 100% proceeded to bone marrow transplant and engrafted, which is the first sign of success — in contrast to the control arm, where only 18% of patients were able to go to transplant and engraft. It’s a clear, marked difference,” commented Actinium CFO Steve O'Loughlin.

“Additionally, Iomab-B was very well-tolerated. Minimal adverse effects and minimal nonrelapse transplant mortality were reported compared to the control arm,” O’Loughlin concluded.

In addition to Iomab-B, Actinium’s drug development pipeline features Iomab-ACT, a lower dose of Iomab-B that is being studied for target  conditioning in advance of CAR-T, a form of cellular therapy that weaponizes patients’ immune cells to attack and kill their cancer. Actinium is collaborating with Sloan Kettering to study Iomab-ACT with the institute’s CD19 CAR-T therapy 19-28z in a Phase 1 trial in patients with relapsed or refractory leukemia. Actinium and Sloan Kettering have been jointly awarded grant funding from the National Institute of Health via its STTR Fast Track program. 

Actinium’s other clinical program, Actimab-A, which has been studied in a Phase 2 clinical trial, is now being studied in two Phase 1 combination trials: one with the salvage chemotherapy regimen CLAG-M and the other with Ventoclax, a targeted therapy jointly developed and marketed by AbbVie and Roche. Actinium is focused on continuing to expand its drug development pipeline by leveraging its Antibody Warhead Enabling (AWE) technology platform.

The AWE Technology Platform

Actinium is the leader in Ac-225-based therapies, the most powerful medical-grade radioisotope. This is a result of the Company’s clinical experience, technology, intellectual property and know-how. The clinical experience encompasses over 500 patients who have been treated with Actinium’s ARCs and through its clinical trials.

Actinium's AWE technology platform is used to produce ARCs, a highly potent and selective form of targeted radiotherapy. ARCs enable the precision targeting of radiation to tumors and its synergistic potential with other therapeutic modalities that cannot be matched by traditional external beam radiation, cytotoxic chemotherapy or biologic therapies. 

AWE-enabled ARCs exploit the use of highly-selective targeted biological agents such as monoclonal antibodies that can seek out and bind cancer antigens found on the tumor cell surface. They deliver potent radioisotopes that are capable of producing double-strand DNA breaks for which there are currently no known resistance or repair mechanisms.

Actinium announced a collaborative research partnership with Astellas Pharma in 2018 to leverage Actinium’s AWE technology platform with select Astellas targeting agents. In 2021, Astellas announced this collaboration will be focused on leveraging its select targeting agents to both image and diagnose cancers. The goal is to treat patients with Actinium’s AWE technology platform using the Ac-225 radioisotope warhead.

2021 and Beyond 

In 2020, Actinium became a fully-integrated, targeted radiotherapy development company by securing laboratory facilities in New York City. These new research facilities function under the guidance of Dale Ludwig, Ph.D., the Company's chief scientific and technology officer, who has over 25 years of oncology discovery research and development experience.

Currently, the SIERRA trial is being conducted at preeminent transplant centers in the U.S., and the Company has begun patient enrollment in the Phase I study of Iomab-ACT for targeted conditioning before treatment in collaboration with Memorial Sloan Kettering Cancer Center. Additionally, Actinium completed enrollment of a second dose cohort in its Actimab-A Venetoclax combination trial for patients with R/R AML, making this a very exciting year for the Company.

Actinium has an IP portfolio of over 140 patents. As of March 31, 2021, the Company had a cash balance of $72 million and as of May 18, 2021, it had a market cap of approximately $156 million. Visit https://www.actiniumpharma.com/ for current news and more information. 

The preceding post was written and/or published as a collaboration between Benzinga’s in-house sponsored content team and a financial partner of Benzinga. Although the piece is not and should not be construed as editorial content, the sponsored content team works to ensure that any and all information contained within is true and accurate to the best of their knowledge and research. This content is for informational purposes only and not intended to be investing advice.