Actinium Pharmaceuticals announced that its drug candidate, Actimab-A, has received orphan designation from the European Medicines Agency (EMA) in the European Union (EU). This designation targets the treatment of patients newly diagnosed with Acute Myeloid Leukemia (AML) who are over the age of 60 and ineligible for standard induction therapy. The decision underscores the potential clinical benefit of Actimab-A in a patient population with limited treatment options.
Significance of Orphan Designation
Orphan designation by the EMA is granted to medicines intended to treat life-threatening or chronically debilitating diseases affecting no more than 5 in 10,000 people in the EU. In addition to meeting the prevalence criteria, Actimab-A had to demonstrate potential clinical benefit over existing therapies like hypomethylating agents such as Decitabine and Azacitidine, which are already authorized for the same indication.
The benefits of orphan designation include up to 10 years of market exclusivity upon marketing authorization, protocol assistance (a specific type of scientific advice for orphan medicines), and fee reductions, which can significantly reduce the cost of drug development.
Actimab-A: Targeted Alpha Particle Immunotherapy
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. It is designed as a first-line monotherapy administered via two 15-minute injections, given 7 days apart.
Actimab-A targets CD33, a protein abundantly expressed on the surface of AML cells, using the monoclonal antibody HuM195. This antibody carries the potent cytotoxic radioisotope actinium-225 to the AML cancer cells. As actinium-225 decays, it emits high-energy alpha particles that kill cancer cells. The decay process also produces a series of daughter atoms, each emitting its own alpha particle, increasing the likelihood of cancer cell destruction.
Clinical Development and Future Prospects
Actimab-A represents a second-generation therapy from Actinium’s HuM195-Alpha program, initially developed at Memorial Sloan Kettering Cancer Center. It has been studied in over 90 patients across four clinical trials. The drug has already been granted Orphan Drug Designation for newly diagnosed AML in patients 60 and above by the U.S. Food and Drug Administration (FDA) and the European Medicines Agency (EMA).
Sandesh Seth, Actinium’s Executive Chairman, stated, “Orphan designation for Actimab-A is an important and exciting milestone for Actinium. I’m extremely proud that our team was able to effectively make the case of potential clinical benefit to patients versus approved therapies and for gaining Actimab-A this important designation.”
