Suppliers are investing in production to support deals with AstraZeneca, Bayer, and other drugmakers that are advancing radioisotope-based cancer therapies.
The emergence of actinium-225 as the next big thing in radiopharmaceuticals is fueling a race to add and access manufacturing capacity for the isotope. With leading drugmakers moving candidates deeper into clinical testing, actinium-225 suppliers have invested to increase capacity and struck a string of deals to meet their customers’ demands for the alpha emitter.
Lutetium-177, a beta-emitting isotope, has defined the growing radiopharmaceutical industry since the FDA approved Novartis’ Lutathera in 2018. Novartis uses the same isotope in Pluvicto, a radioligand therapy that the FDA approved in 2022. Combined, Lutathera and Pluvicto, both cancer drugs, generated sales of $2.8 billion for Novartis in 2025.
Drugmakers are continuing to invest in cancer medicines based on lutetium-177. Novartis is running multiple trials to build on its leadership. ITM filed for approval in November, and companies, including Eli Lilly, are moving assets through the clinic. At the same time, the sector’s focus is expanding beyond lutetium-177, with companies studying a growing set of isotopes led by actinium-225 in pursuit of a competitive advantage. Now, suppliers of the alpha emitter are ramping up.
Adding Actinium-225 Capacity
Compared to lutetium-177, actinium-225 emits more energy over a smaller area. Therapies based on it could be more efficacious, as they are thought to cause more double-strand DNA breaks in cancer cells and result in less damage to healthy tissues.
Novartis discussed its expansion into alpha emitters, and actinium in particular, at an R&D day in 2019, but it took a few more years for the sector to ignite. From October 2023 to March 2024, AstraZeneca, Bristol Myers Squibb, and Lilly each struck deals to buy biotechs developing drug candidates based on actinium-225. The proliferation of programs has strained the supply chain, leading BMS’ RayzeBio to pause a Phase 3 trial over a shortage of actinium-225 in 2024.
Oak Ridge National Laboratory (ORNL) has been the main supplier of actinium-225 for almost 30 years. The R&D center, which is funded by the Department of Energy (DOE), makes the isotope via decay of thorium-229 left over from nuclear programs in the 1940s and 1950s. ORNL has increasedshipments, but the growth in demand has outpaced its ability to boost output.
Multiple groups are working to increase supply. TerraPower Isotopes is increasing access to actinium-225 generated through natural decay by working with Isotek to recover the thorium-229 from uranium-233 stockpiles managed by the DOE.
Overseen by the DOE, ORNL and two other national laboratories have used accelerator beam facilities to make actinium-225 from thorium-232. However, material generated in that process is contaminated with actinium-227, leading to the development of alternative approaches such as cyclotrons and linear accelerators.
NorthStar CEO Frank Scholz said that considerations related to yield, reliability, and scalability informed his company’s decision to use electron accelerator–based technology to make actinium-225. Scholz said NorthStar selected the technology after calculating it would need to buy 10 to 15 cyclotrons, depending on the model, to meet its supply needs.
“That would mean a significant amount of capital expenditure and mean using multiple machines that could fail and need to be maintained,” Scholz said. “The decision goes beyond the pure technical aspect, which we value, and is ultimately a holistic business case.”
NorthStar’s actinium-225 is made without the addition of stable elements, resulting in a more potent product known as a non-carrier-added isotope. NorthStar recently claimed to be the first to produce commercial-scale non-carrier-added actinium-225 using electron accelerator technology.
BWXT Medical makes non-carrier-added actinium-225 at TRIUMF, Canada’s particle accelerator center. Niowave uses a superconducting electron linear accelerator. Eckert & Ziegler use a cyclotron-based method.
Drugmakers Secure Supply
The investments in capacity reflect industry demand for actinium-225. AstraZeneca struck a 10-year supply agreement with Niowave in December. The deal, which extended an earlier agreement, secured AstraZeneca a source of actinium-225 for use in drug candidates it acquired in its $2.4 billion Fusion Pharmaceuticals buyout in 2024. Fusion partnered with BWXT Medical to access the isotope in 2023.
Bayer has entered into a string of actinium-225 supply agreements in recent years, agreeing to source the isotope from BWXT, Ionetix, NorthStar, and PanTera between 2022 and 2024. Cellectar Biosciences diversified its supply chain by striking deals to access the isotope from NorthStar, ITM, Nusano, and Ionetix in 2024 and 2025.
Point Biopharma, which Eli Lilly bought for $1.4 billion, partnered with Ionetix to source actinium-225 in 2021. Lilly invested in Ionetix in 2024. Ariceum Therapeutics penned a deal in 2025 for actinium-225 from ITM’s joint venture with Canadian Nuclear Laboratories. Eckert & Ziegler has inked a series of deals, agreeing to supply actinium-225 to Actinium Pharmaceuticals, GlyTherix, and SK Biopharmaceuticals.
Investments in drug candidates based on other isotopes indicate the need for manufacturing capabilities to keep evolving. Nucleus RadioPharma CEO Steve Hahn said that copper-67 and astatine-211 are isotopes that are not made in sufficient quantities. The isotopes are part of an increasingly diverse pipeline.
Justin Butler, a partner at Eclipse Ventures, said he anticipates there will be drug candidates not only involving lutetium and actinium, but also lead and copper isotopes. “We need to have the capabilities to be able to work with all of those if this industry is really going to become as big as we think it can be.
Author |Nick Paul Taylor
Nick is a freelance writer who has been reporting on the global life sciences industry since 2008. With a BSc in biology, Nick writes about the science and business of biopharma and medtech for numerous healthcare publications. He can be reached at nick.paul.taylor@gmail.com
