Actinium Pharmaceuticals, Inc., a biopharmaceutical company, has submitted an application with the European Medicines Agency (EMA) seeking Orphan Designation for Actimab-A for patients newly diagnosed with acute myeloid leukemia (AML) age 60 and above who are ineligible for currently used induction therapies.

Actimab-A is currently in a 53-patient, multicenter open label Phase 2 trial where it is being studied as a monotherapy in these patients who have low peripheral blast (PB) burden. In a previously completed Phase 1 trial, Actimab-A showed a 50% composite response rate at the dose level of 2.0 µCi/kg/fraction, which is the dose level being studied in the current phase 2 trial, in patients with low PB burden.

“Orphan designation brings significant benefits to the drug development process,” said Sandesh Seth, executive chairman of Actinium Pharmaceuticals. “We are excited to have submitted this application with the EMA and we are optimistic that Actimab-A will soon have orphan designation in the EU just as it does in the US. If this were to occur, both of our clinical product candidates, Iomab-B and Actimab-A, would have orphan designation in the US and EU, which are the largest addressable markets for our product candidates.”

Actimab-A, Actinium's most advanced alpha particle immunotherapy (APIT) product candidate, is currently in a 53-patient, multicenter Phase 2 trial for patients newly diagnosed with AML age 60 and above. 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 calls. 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 age 60 and above.

Actinium Pharmaceuticals, Inc. is a biopharmaceutical company developing innovative targeted therapies for patients with cancers lacking effective treatment options.