Leukemia Treatment Receives Orphan Drug Designation

Actimab-A is an alpha radiolabeled antibody in development for newly diagnosed acute myeloid leukemia patients over the age of 60.

The FDA last week granted orphan drug designation to an experimental medication that treats older patients with acute myeloid leukemia (AML).

Actimab-A, which is manufactured by Actinium Pharmaceuticals, Inc, is an alpha radiolabeled antibody in development for newly diagnosed AML in patients over 60 years of age. The drug is currently in a multicenter phase 1/2 clinical trial.

Actinium released promising interim data from the ongoing trials on November 6, 2014. As part of the trial, researchers found that median overall survival in 7 secondary AML patients with prior myelodysplastic syndrome was 9.1 months, compared with historical norms of 2 to 5 months overall survival depending on the treatment modality.

The drug is comprised of the CD33 antibody lintuzumab linked to the actinium-225 payload. Actimab-A has garnered support from leading experts at “prestigious and high-volume” cancer treatment hospitals as a result of the potential safety and efficacy profile, in addition to its potency, specificity, and ease of use, according to Actinium.

Older patients with AML face a higher risk from the disease, while secondary patients are considered to have a more severe and less treatable form of AML. As a result, these patients have a shorter expected survival time.

Actinium anticipates additional data from the ongoing trial to be available in 2015.

"The FDA's decision to grant orphan-drug status for Actimab-A is a significant milestone for the company and recognizes the need for innovative new approaches to treat AML,” Kaushik J. Dave, PhD, president and CEO of Actinium, said in a press release. “The designation will provide Actinium access to various development benefits and financial incentives from the agency, including an exemption from prescription drug user fees for Actimab-A for this indication and, if the drug receives marketing approval, it will enjoy 7 years of market exclusivity in the United States."