Astellas Pharma and Actinium Pharmaceuticals will develop Actinium-225 Radio-Conjugates (ARCs).

Radio-conjugates are targeted radioimmunotherapies, most often developed for the treatment of cancer. New York-based Actinium Pharmaceuticals is developing actinium 225-based radioimmunotherapies for cancers that currently lack effective treatments. The company uses monoclonal antibodies (mAbs) to deliver radioisotopes directly to cancer cells, allowing for their targeted destruction. Actinium has three candidates in development, including Iomab-B for use in preparing patients with blood-borne cancers for bone marrow transplants, Actimab-A for patients age 60 and over that are newly diagnosed with acute myeloid leukemia; and Actimab-M for the treatment of patients with relapsed or refractory multiple myeloma.

In November 2017, Actinium launched its Actinium Warhead Enabling (AWE) Program based on its AWE Platform Technology, which enables the preparation of stable Actinium-225 (²²⁵Ac) Radio-Conjugates (ARCs). The company holds patents on the use of the chelator DOTA and its derivatives, as well as on methods of chelation and ²²⁵Ac labeling. The AWE Program is designed to provide collaborators with access to Actinium’s drug development expertise and AWE Technology Platform to achieve accelerated development times for ARCs.

Recently, Actinium reported that its AWE Platform Technology provided successful results for the CD38 targeting blockbuster drug Darzalex^TM (daratumumab), with the ²²⁵Ac-enabled drug providing superior cell-killing properties. 

Now the company has entered into a research and option agreement with Astellas Pharma to develop ARCs using its AWE technology. Actinium will prepare ²²⁵Ac conjugates of selected Astellas targeting agents and conduct preclinical validation studies on the ARCs. As part of the agreement, Actinium will receive upfront payments and research funding from Astellas.

Said Actinium Chief Scientific Officer Dr. Dale Ludwig: “We are thrilled to be working with Astellas, a global leader at the forefront of healthcare innovation, on this exciting collaboration. Our AWE Platform introduces a novel and complementary mechanism of action which is supported by significant preclinical and clinical data. We are well positioned to execute on this exciting collaboration and look forward to advancing the field of Actinium-225 Radio-Conjugates through this collaboration with Astellas.”