IAEA Brings 21 Countries Together to Advance Actinium-225 Targeted Cancer Therapies

The International Atomic Energy Agency (IAEA) is bringing researchers from 21 countries together to advance actinium-225 (Ac-225) radiopharmaceuticals, strengthening the scientific partnerships and technical capabilities needed to move emerging targeted cancer therapies closer to clinical application.

Its coordinated research project, Production and Quality Control of Ac-225 Radiopharmaceuticals, is developing shared protocols for producing, testing and evaluating these treatments, with the final phase focused on turning research findings into guidance that countries with different levels of technical capacity can use.

Participants reviewed progress at the project's third research coordination meeting in August 2026, where a dedicated industry session examined production capabilities, supply constraints and opportunities to connect research institutions with companies developing the Ac-225 supply chain.

Targeted therapies depend on reliable production and testing

Targeted alpha therapy uses alpha-emitting radionuclides delivered directly to cancer cells, offering the potential to destroy malignant tissue locally and limit damage to surrounding healthy tissue, an approach that has attracted growing interest in nuclear medicine.

Ac-225 is among the radionuclides receiving international attention for its favourable therapeutic properties and potential to improve outcomes for patients with certain cancers, although further progress depends on reliable supplies, continued radiopharmaceutical development and rigorous quality control.

Bringing these therapies closer to patients requires specialist expertise and quality assurance throughout radionuclide production, radiopharmaceutical development, preclinical evaluation and eventual clinical application, making coordination between institutions an important part of the research.

Tzanka Wheldon, Director of the IAEA Division of Physical and Chemical Sciences, said international collaboration was essential to developing Ac-225's full potential, describing the agency's role as connecting Member States, research institutions and industry to support innovation and strengthen technical capacity.

Shared materials and methods support practical research

Participating institutions have exchanged materials, analytical methods, protocols and expertise, including Ac-225 samples produced through different routes, chelating agents and new ligands used in radiopharmaceutical development.

The exchanges cover standard operating procedures, radiolabelling techniques and quality control methods, helping researchers address common technical problems and build national capabilities for the safe and effective development of Ac-225 radiopharmaceuticals.

Institutions will conduct interlaboratory comparisons using the same protocols to identify differences in measurements and procedures, supporting more consistent methods across the research network.

This work is particularly important because Ac-225 remains limited in availability, and its production route can affect radionuclidic purity, radiochemical performance and quality control results, creating challenges that individual institutions may struggle to resolve independently.

Pooling resources, infrastructure and expertise gives participants access to practical training and knowledge transfer, supporting joint research, shared good practices and scientific relationships that can continue beyond the project.

Industry partnerships shape the project's final phase

Representatives from NorthStar Medical Radioisotopes, ROSATOM, ITM Isotope Technologies Munich, Bayer and PanTera joined researchers at the August meeting, bringing industry perspectives on current production capacity and the supply challenges facing Ac-225 development. Discussions examined how closer cooperation could connect research requirements with emerging supply needs, strengthen knowledge and technology transfer, and support wider access to targeted alpha therapies as development progresses.

Vicky Gonzalez, a chemist in the IAEA's Radiochemistry and Radiation Technology Section, said the project's final phase would focus on turning scientific progress into lasting collaboration through harmonized methodologies and thematic working groups.

The resulting guidance and partnerships are intended to help participating countries build on the research, creating a more connected international network capable of addressing the production, testing and development challenges that remain before broader clinical application.