Convergent Therapeutics plans to radiolabel its CONV01-α radiopharmaceutical agent for prostate cancer with NorthStar Medical Radioisotopes’ high purity non-carrier-added Actinium-225.

CONV01-α is a prostate-specific membrane antigen-targeted monoclonal antibody that is under investigation as a potential treatment for prostate cancer. It is designed to bind to the PSMA and become an internalized part of it that delivers a powerful radioactive dose directly into prostate cancer cells.

It is made from a combination of CONV01 and Ac-225, a high energy alpha-emitting radioisotope that has been used increasingly in clinical studies on radiopharmaceutical therapy and directly delivers dose to localized areas of cancer cells. It enhances the tumor destroying capabilities of CONV01-α, while minimizing radiation to adjacent, healthy tissue.
NorthStar produces n.c.a. Ac-225 that is environmentally sustainable and non-uranium based in a production process that uses state-of-the-art electron beam accelerator technology to increase capacity and create flexible scheduling.

“When CONV01 is bound to the alpha particle emitting actinium-225, making CONV01-a, the result is a powerful drug with a wide therapeutic index in men with prostate cancer. Our collaboration with NorthStar will secure an adequate actinium-225 supply for clinical trials and eventual commercial use,” Dr. Philip Kantoff, co-founder and chief executive officer at Convergent Therapeutics, told HCB News.

The half-life of Ac-225 is what limits the exposure of healthy tissue to radioactivity, but clinical research and commercial use are hindered by a chronic short supply, brought on by limitations in current production technology.

NorthStar is expected to be the first commercial-scale producer of Ac-225 for advanced clinical research and commercialization of radiopharmaceutical products. It will produce it using its environmentally-sound electron accelerator technology, which will ensure the product is free of long-lived radioactive contaminants and byproducts related to other production methods. This, in turn, will eliminate regulatory and waste management challenges for hospitals and health systems.

The company became the first U.S.-based source of molybdenum-99 (Mo-99), the parent isotope of technetium-99 (Tc-99m), back in 2018, after more than 25 years of no domestic source in the country. This created greater access for providers to a stable supply of a diagnostic agent commonly used in imaging procedures to detect potential diseases such as coronary artery disease and cancer.

"NorthStar is applying the same development expertise to rapidly advance large-scale production of n.c.a. Ac-225 that has positioned us at the forefront of U.S. radioisotope production as the only commercialized producer of the important medical radioisotope molybdenum-99 (Mo-99)," said Stephen Merrick, president and chief executive officer of NorthStar Medical Radioisotopes, in a statement.

NorthStar expects to begin constructing its actinium-225 production facility soon, with initial production of the radiochemical grade Ac-225 planned for late 2023.

It will submit a Drug Master File to the FDA in 2024.

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