Anti-BCMA Immuno-NanoPET Radiotracers for Improved Detection of Multiple Myeloma

Current clinical imaging modalities for the sensitive and specific detection of multiple myeloma (MM) rely on nonspecific imaging contrast agents based on gadolinium chelates for magnetic resonance imaging (MRI) or for F-18-FDG-directed and combined positron emission tomography (PET) and computed tomography (CT) scans. These tracers are not, however, able to detect minute plasma cell populations in the tumor niche, leading to false negative results. Here, a novel PET-based anti-BCMA nanoplatform labeled with Cu-64 is developed to improve the monitoring of these cells in both the spine and femur and to compare its sensitivity and specificity to more conventional immunoPET (Cu-64 labeled anti-BCMA antibody) and passively targeted PET radiotracers ((CuCl2)-Cu-64 and F-18-FDG). This proof-of-concept preclinical study confirmed that by conjugating up to four times more radioisotopes per antibody with the immuno-nanoPET platform, an improvement in the sensitivity and in the specificity of PET to detect tumor cells in an orthotopic model of MM is observed when compared to the traditional immunoPET approach. It is anticipated that when combined with tumor biopsy, this immuno-nanoPET platform may improve the management of patients with MM.

Automated summary

A novel PET-based anti-BCMA nanoplatform labeled with Cu-64 has shown improved sensitivity and specificity in monitoring minute plasma cell populations in the spine and femur compared to traditional immunoPET approaches in detecting tumor cells in MM patients. This immuno-nanoPET platform has the potential to enhance the management of MM patients when combined with tumor biopsy.