The University of Pennsylvania Health System (UPenn) in Philadelphia, has joined Actinium Pharmaceuticals' ongoing phase I/II trial in newly diagnosed elderly patients with acute myeloid leukaemia (AML). The trial is designed to establish the safety and efficacy of API’s drug Actimab-A in AML patients over the age of 60.

Actimab-A treatment consists of the isotope Actinium 225 attached to the anti-CD33 monoclonal antibody lintuzumab (HuM195).

“We are pleased to welcome UPenn as an additional site in our multi-centre trial, another clear validation point as we continue to make solid progress,” said Jack Talley, CEO of Actinium Pharmaceuticals. “Five of the leading leukaemia treatment centres that have been setting the pace in new approaches to AML have now expressed their readiness to be our partners in bringing the benefits of alpha particle immunotherapy technology to patients in need of new approaches. We look forward to building on this momentum throughout the year.”

The University of Pennsylvania Health System is the fifth centre to sign a clinical trial agreement with Actinium Pharmaceuticals, following Memorial Sloan Kettering Cancer Centre (MSKCC) in New York, Fred Hutchinson Cancer Research Centre (FHCRC) in Seattle, Washington, MD Anderson Cancer Centre in Houston, Texas and Johns Hopkins in Baltimore, Maryland.

The phase I/II multi-centre Actimab study builds on the previous phase I/II Bismab-A study with a less potent bismuth-213 (Bi-213) isotope and an earlier Actimab-A phase I study (where only a single dose of Actimab was administered). The phase II portion of the  earlier Bismab-A study demonstrated the efficacy of API’s alpha particle platform by producing a number of complete responses in difficult-totreat relapsed, secondary and poor cytogenetics AML patients with no standard of care options available.

The goal of the current study is to confirm the efficacy and safety of Actimab-A using the same antibody targeting mechanism with the actinium isotope, produced by an improved method of manufacture, and to study the effect of multiple doses of treatment. The population for this study will be patients with newly diagnosed AML who are over the age of 60, an age in which many chemotherapy regimens are not well tolerated. In other published studies in AML, newly diagnosed patients had better responses than relapsed patients.

Actimab-A is a drug candidate construct made using Actinium Pharmaceuticals’ proprietary patented technology for arming monoclonal antibodies with alpha emitters actinium 225 and bismuth 213. Antibodies are used as high precision delivery systems that bring powerful alpha emitters into or immediately next to targeted cancer cells.  Actimab-A consists of the Lintuzumab monoclonal antibody and 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. The technology was first developed by Dr. David Scheinberg at Memorial Sloan Kettering Cancer Centre. Lintuzumab is a monoclonal antibody that targets CD33, found on myeloid leukaemia  cells. It is the humanized version of M195, the antibody initially developed by Dr. David Scheinberg of Memorial Sloan Kettering Cancer Centre.

Actinium Pharmaceuticals, Inc. (API), a public biopharmaceutical company that develops innovative targeted payload immunotherapeutics.