FDA allows pivotal trial of Actinium's armed-antibody isotope delivery

Actinium Pharmaceuticals spoke with the FDA last week and is now planning to roll out a Phase III pivotal trial of its targeted immunotherapeutic cancer treatment using its radioisotope delivery platform.

The U.S. agency told Actinium that positive results from the single study of Iomab-B would put it on the path to approval. The primary endpoint is complete remission lasting 6 months; considering 100% of the leukemia and myelodysplastic syndrome patients in the Phase I/II trial achieved this, things are looking good for Actinium.

New York-based Actinium's delivery platform is a targeted form of radiotherapy that "arms" antibodies with radioactive isotopes and carries them directly to tumors while mitigating the radiation effects on healthy cells. The monoclonal antibody BC8 carries iodine 131 radioisotopes to target the antigen CD45, which is expressed on white blood cells. Thus, Iomab targets white blood cells before stem cell transplantation for blood cancers, including myeloid leukemia, chronic myeloid leukemia, acute lymphoblastic leukemia, chronic lymphocytic leukemia, Hodgkin disease, Non-Hodgkin lymphomas and multiple myeloma.

In patients over 55, there are currently no FDA-approved treatments for acute myeloid leukemia and no standard of care, according to the company.

"This puts us on our way to start a registration trial, eagerly anticipated not only by the company but also by leukemia experts, next year," Actinium CEO Kaushik Dave said in a statement. "We are delighted with the enthusiasm that Iomab-B generated among leading leukemia physicians and their interest in participating in our trial, which further validates the large and unmet opportunity for a safe and effective drug in this space. We anticipate based on this enthusiasm that the study enrollment will be swifter than originally expected."

Actinium also has its candidate Actimab-A in early trials. Actimab-A delivers powerful alpha emitters into or near targeted cancer cells, also with an antibody approach. The technology was first developed at Memorial Sloan Kettering Cancer Center.

- here's the release