The motivation: At-211 has demonstrated potential to treat blood, ovarian, and specific types of brain cancers. However, its short half-life of 7.2 hours makes it a challenge to generate substantial quantities for therapeutic doses and necessitates regional production and distribution.
Ethan Balkin, program manager for radioisotope research and development for the DOE-IP, represented the United States at the symposium. The DOE-IP is a primary producer of At-211 in the United States through its University Isotope Network institutions.
“One nation is not going to be able to produce enough to supply the global demand. It's just not feasible. The 7.2-hour half-life is working against you and there aren't enough cyclotrons or accelerators capable of producing it to facilitate a global supply,” Balkin said. “The WAC seeks to enable global astatine researchers to explore the full potential of At-211 for therapy.”
WAC goals and U.S. commitments: The WAC is open to all nations that want to be involved and “aims to facilitate communication, sharing of technology, and collaborative research globally to optimize and grow regional At-211 production networks internationally,” according to the NIDC. By increasing availability of At-211, the WAC’s founding members hope to motivate clinical interest in the radioisotope and make clinical medical trials more viable.
The DOE-IP made three commitments when joining the WAC: 1) to advance the science of At-211 through domestically funded U.S. research, 2) to partner to enable a global increase in At-211 production capacity, and 3) to motivate clinical interest in At-211 through increased availability.
One way the DOE-IP plans to meet its commitments is by making an At-211 target station designed at the University of Washington Medical Cyclotron Facility, with DOE-IP funding broadly available through nonexclusive licensing. The work that went into developing that target system and delivering At-211 to patients at UW’s Fred Hutchinson Cancer Center was described by the NIDC—and Newswire—in the fall of 2022.
More on the station: According to the NIDC, the target station developed at the University of Washington was designed to fit standard beamlines and to be compatible with commercial transfer systems for automated removal of irradiated targets. The target cooling features of the target station are optimized for At-211 production, and robust beam diagnostics are built into the station, according to the NIDC.
“This target station is a game changer. There is a uniform target design in which most isotope producers that utilize cyclotrons will recognize. It's a coin-type target, so it's not a unique target geometry. The ability to have something that is universally used is advantageous when it comes to getting around the table and freely sharing scientific ideas,” Balkin said.
