Allowed patent application claims method for purifying actinium-225

NEW YORK, Nov. 14, 2016 (GLOBE NEWSWIRE) -- Actinium Pharmaceuticals, Inc. (NYSE MKT:ATNM) ("Actinium" or "the Company"), a biopharmaceutical Company developing innovative targeted payload immunotherapeutics for the treatment of advanced cancers, announced today that the Company received a notice of allowance from the United States Patent and Trademark Office (USPTO) for a patent claiming the purification of actinium-225 (Ac-225), the alpha-emitting radioisotope used in Actimab-A. Actimab-A is currently in a Phase 2 clinical trial in patients newly diagnosed with Acute Myeloid Leukemia (AML) who are over the age of 60.

Kaushik J. Dave, Ph.D., MBA, Chief Executive Officer of Actinium said, “We are pleased to receive this Notice of Allowance from the USPTO. Thanks in large part to our intellectual property and know how, Actinium is a leader in the radioimmunotherapy field. We will continue to strengthen this leadership position with additional intellectual property and know how as we simultaneously progress Iomab-B, Actimab-A and future drug candidates through clinical trials.”

Actinium recently reported results from a Phase 1 trial of Actimab-A, which will be presented in a poster session on December 5, 2016 at the 58^th Annual Meeting of the American Society of Hematology (ASH) being held in San Diego, California from December 3 – 6, 2016. The Phase 1 trial treated 18 patients (median age, 77 years; range, 68-87 years) in a dose escalation study with doses ranging from 0.5 – 2.0 μCi/kg/fraction with a 28% response rate observed across the 4 dosing cohorts. Peripheral blast burden was identified as a strong predictor of response and this finding will be factored into the Phase 2 clinical trial protocol by incorporating the use of hydroxurea to lower peripheral blast burden prior to Actimab-A administration. The Phase 2 trial will enroll 53 patients who will receive 2 fractions of 2.0 μCi/kg of Actimab-A one week apart. In the Phase 1 study, patients who had low peripheral blast burden and who received the 2.0 μCi/kg/fraction of Actimab-A showed a 50% response rate.

The Actimab-A Phase 1 poster abstract is viewable through the following page:
https://ash.confex.com/ash/2016/webprogram/Paper91235.html.

“Actimab-A is showing promising safety and efficacy signals, which gives us great excitement for our current Phase 2 trial,” said Sandesh Seth, Executive Chairman of Actinium. “The Notice of Allowance for this patent is a welcome addition to our intellectual property portfolio. We look forward to providing updates on the advancement of our Actimab-A program, specifically the interim analysis that is expected in mid-2017 and the completion of enrollment by the end of 2017.”

About Actimab-A

Actimab-A, Actinium's most advanced alpha particle immunotherapy (APIT) program, is in a Phase 2 clinical trial for patients newly diagnosed with AML over the age of 60. Actimab-A is being developed as a first-line therapy and it has attracted support from some of the leading experts at the most prestigious cancer treatment hospitals due to the potential of its safety and efficacy profile. Actimab-A consists of the monoclonal antibody, HuM195, and the radioisotope, actinium-225. Actinium-225 decays by giving off high-energy alpha particles, which kill cancer cells. When actinium decays, it produces a series of daughter atoms, each of which gives off its own alpha particle, increasing the chances that the cancer cell will be destroyed. HuM195 is the humanized version of M195 and is a monoclonal antibody that targets CD33, which is abundantly found on myeloid leukemia cells. Both the alpha particle technology and HuM195 were initially developed at Memorial Sloan Kettering Cancer Center. Actimab-A is a second-generation therapy from the Company’s HuM195-Alpha program, which has now been studied in almost 90 patients in four clinical trials.

About Actinium Pharmaceuticals

Actinium Pharmaceuticals, Inc. (www.actiniumpharma.com) is a New York-based biopharmaceutical company developing innovative targeted payload immunotherapeutics for the treatment of advanced cancers. Actinium's targeted radioimmunotherapy products are based on its proprietary delivery platform for the therapeutic utilization of alpha-emitting Actinium-225 and Bismuth-213 and certain beta emitting radiopharmaceuticals in conjunction with monoclonal antibodies. The Company's lead radiopharmaceutical product candidate Iomab-B is designed to be used, upon approval, in preparing patients for hematopoietic stem cell transplant, commonly referred to as bone marrow transplant. The Company is conducting a single, pivotal, multicenter Phase 3 clinical study of Iomab-B in refractory or relapsed AML patients over the age of 55 with a primary endpoint of durable complete remission. The Company's second product candidate, Actimab-A, is in a 53 patient, multicenter, open-label Phase 2 trial for patients newly diagnosed with AML over the age of 60 in a single-arm multicenter trial.

Forward-Looking Statements for Actinium Pharmaceuticals, Inc. 

This news release contains "forward-looking statements" as defined in the Private Securities Litigation Reform Act of 1995. These statements are based on management's current expectations and involve risks and uncertainties, which may cause actual results to differ materially from those set forth in the statements. The forward-looking statements may include statements regarding product development, product potential, or financial performance. No forward-looking statement can be guaranteed and actual results may differ materially from those projected. Actinium Pharmaceuticals undertakes no obligation to publicly update any forward-looking statement, whether as a result of new information, future events, or otherwise.

Contact:

Actinium Pharmaceuticals, Inc.

Steve O'Loughlin
Vice President, Finance and Corporate Development
soloughlin@actiniumpharma.com

Released November 14, 2016