The radiopharmaceutical sector is experiencing increased competition to secure supplies of actinium-225, an isotope that is gaining attention as companies advance new cancer therapies. As more drugmakers move their actinium-225-based candidates into clinical development, suppliers are investing in expanded manufacturing capacity and signing agreements to meet the rising demand.
Lutetium-177 has been a key isotope for the industry since Novartis’ Lutathera received FDA approval in 2018. The company’s Pluvicto, also based on lutetium-177, was approved by the FDA in 2022. Combined sales of these two cancer drugs reached $2.8 billion for Novartis in 2025.
Pharmaceutical companies continue to develop lutetium-177-based treatments, with Novartis conducting multiple trials and ITM filing for regulatory approval in November. Eli Lilly and other firms are also advancing assets through clinical stages. However, attention is shifting toward other isotopes such as actinium-225, which emits higher energy over a smaller area compared to lutetium-177. This property could make actinium-225 therapies more effective at targeting cancer cells while minimizing harm to healthy tissue.
Novartis first discussed its interest in alpha emitters like actinium during a 2019 R&D event, but significant industry activity began several years later. Between October 2023 and March 2024, AstraZeneca, Bristol Myers Squibb (BMS), and Lilly acquired biotechs developing actinium-225-based drug candidates. The rapid expansion of these programs has put pressure on supply chains; BMS’ RayzeBio paused a Phase 3 trial in 2024 due to an actinium-225 shortage.
Oak Ridge National Laboratory (ORNL), funded by the Department of Energy (DOE), has supplied most of the world’s actinium-225 for nearly three decades by extracting it from thorium-229 stockpiles dating back to mid-century nuclear programs. While ORNL has increased shipments, demand now exceeds its production capabilities.
To address this gap, organizations like TerraPower Isotopes are collaborating with Isotek to recover thorium-229 from uranium-233 managed by the DOE. ORNL and two other national labs have also produced actinium-225 using accelerator beam facilities with thorium-232 as a source material; however, this process results in contamination with actinium-227. Alternative methods such as cyclotrons and linear accelerators are being developed.
Frank Scholz, CEO of NorthStar Medical Radioisotopes, explained his company’s approach: “That would mean a significant amount of [capital expenditure] and mean using multiple machines that could fail and need to be maintained,” Scholz said regarding cyclotron use. “The decision goes beyond the pure technical aspect, which we value, and is ultimately a holistic business case.” NorthStar uses electron accelerator technology to produce non-carrier-added actinium-225 without stable element additives—a process it claims was achieved at commercial scale for the first time recently.
Other suppliers include BWXT Medical at Canada’s TRIUMF facility using particle accelerators; Niowave with superconducting electron linear accelerators; and Eckert & Ziegler employing cyclotron-based methods.
Drugmakers have responded by securing long-term supply agreements. In December, AstraZeneca signed a decade-long deal with Niowave for access to actinium-225 needed for drug candidates acquired through its $2.4 billion purchase of Fusion Pharmaceuticals in 2024; Fusion had previously partnered with BWXT Medical for isotope access in 2023.
Bayer has arranged multiple supply agreements since 2022—including deals with BWXT Medical, Ionetix, NorthStar and PanTera—while Cellectar Biosciences diversified its sources through contracts with NorthStar, ITM, Nusano and Ionetix between 2024 and 2025.
Point Biopharma partnered with Ionetix in 2021 before being acquired by Eli Lilly for $1.4 billion; Lilly later invested directly in Ionetix in 2024. Ariceum Therapeutics secured supply from ITM’s joint venture with Canadian Nuclear Laboratories last year. Eckert & Ziegler have signed agreements to provide actinium-225 to Actinium Pharmaceuticals, GlyTherix and SK Biopharmaceuticals.
As research expands into additional isotopes such as copper-67 and astatine-211—which Nucleus RadioPharma CEO Steve Hahn noted are not yet produced at sufficient scale—the need for flexible manufacturing continues to grow.
Justin Butler of Eclipse Ventures commented: “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.”
