NorthStar Medical Radioisotopes, LLC and Inhibrx, Inc. announced a collaboration to develop and produce novel radiopharmaceuticals for the treatment of cancer. Inhibrx will use its optimized single-domain antibodies (sdAbs) to create a new generation of targeted alpha therapies. Inhibrx has an extensive history of sdAb innovation and has developed a library of sdAbs targeting tumor-associated antigens.

sdAbs are ideal biological targeting agents for delivery of radioisotopes, due to their high binding affinity and specificity to tumor cells or antigen-expressing cells within the tumor microenvironment. Alpha-emitting radioisotopes have a short range of activity and high energy transfer and, when targeted, allow for precise killing of cancer cells with minimal damage to surrounding healthy tissues. NorthStar is expanding its industry-leading position in the growing area of therapeutic radioisotopes and is now poised to be the first commercial-scale producer of non-carrier added (n.c.a.) actinium-225 (Ac-225) and copper-67 (Cu-67).

In the past, drugs containing Ac-225 have shown clinical efficacy, but previous iterations have been limited by lack of sufficient actinium supply. The union of precision-targeted sdAbs with an ample actinium supply has the potential to enable development of novel targeted radiopharmaceutical therapies that may provide accessible, effective options for cancer treatment. Under this agreement with Inhibrx, NorthStar will support the development of a prespecified number of Inhibrx's novel biologic products by providing the Ac-225 supply and access to its integrated radiopharmaceutical contract development and manufacturing organization (CDMO) services.

NorthStar will also prepare Inhibrx patient doses for clinical studies and, upon approval, may manufacture and supply radionuclides for Inhibrx's commercial use.