Sandesh Seth, Chairman and Chief Executive Officer of Actinium Pharmaceuticals, provides an update on its Actimab-A drug candidate in acute myeloid leukemia (AML). The Phase 2 trial is currently enrolling patients with AML age 60 and older who are unfit for standard induction chemotherapy. The Phase 2 clinical trial is now active at 16 clinical trials sites and Actinium has reiterated its previously announced guidance for the trial including a planned interim analysis by the end of 2017 and top line data in the first half of 2018. AML is one of the most common forms of leukemia. Approximately 21,000 patients are diagnosed with AML each year with the median ago of diagnosis being 68 years of age. Patients with AML over the age 60 who are ineligible for standard induction chemotherapy have limited treatment options and have a poor prognosis. Actinium’s Actimab-A targets CD33, a marker expressed in approximately 80-90 percent of patients with AML, via a monoclonal antibody that has been linked to actinium-225 (“Ac-225”), an alpha emitting radioisotope.

Sandesh Seth said, “CD33 is a validated target in AML and in our experience a resurgent area of interest amongst the medical community post the recent reapproval of Mylotarg. Importantly, the CD33 space that continues to garner much interest as evidenced by recent drug approvals, strategic transactions and a robust development pipeline represented by several major pharmaceutical and biotechnology companies. We believe that Actimab-A has the potential to be best in the CD33 class given the combination of its potency as a single agent, its relatively simple administration via two injections, and its relative benign safety profile. We look forward to updating by year-end on the significant progress we are making with the Actimab-A trial.”

Actimab-A, Actinium’s most advanced alpha-particle therapy product candidate, is currently in a 53-patient, multicenter Phase 2 trial for patients newly diagnosed with AML age 60 and above that are ineligible for standard induction chemotherapy. Actimab-A is being developed as a first-line therapy and is a monotherapy that is administered via two 15-minute injections that are given 7 days apart. Actimab-A targets CD33, a protein abundantly expressed on the surface of AML cells via the monoclonal antibody, HuM195, which carries the potent cytotoxic radioisotope actinium-225 to the AML cancer cells. Actinium-225 gives off high-energy alpha particles as it decays, which kill cancer cells and as actinium-225 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. Actimab-A is a second-generation therapy from the Company’s HuM195-Alpha program, which was developed at Memorial Sloan Kettering Cancer Center and has now been studied in almost 90 patients in four clinical trials. Actimab-A has been granted Orphan Drug Designation for newly diagnosed AML in patients 60 and above by the U.S. Food and Drug Administration.