Kondapa Naidu Bobba, PhD, presents JNM paper Highlighting Radiolabeling Methodology

Kondapa Naidu Bobba, PhD, an assistant professional researcher in the UC San Francisco Department of Radiology & Biomedical ImagingKondapa Naidu Bobba, PhD, is first author of "Evaluation of 134Ce/134La as a PET Imaging Theranostic Pair For 225Ac -Radiotherapeutics," a Journal of Nuclear Medicine (JNM) article published May 18 that discusses the development of a robust radiolabeling methodology and applied optimized method for utilizing prostate cancer targeting agents PSMA-617 and antibody YS5. Dr. Bobba, an assistant professional researcher in the UC San Francisco Department of Radiology & Biomedical Imaging, performed his research investigations with PI Robert Flavell, MD, PhD, chief of Molecular Imaging and Therapeutics, and the corresponding author. Additional authors included Henry VanBrocklin, PhDYoungho Seo, PhD, as well as colleagues from UCSF and the University of Virginia.

The JNM article addresses the challenge of dosing with the therapeutic nuclide 225Ac due to low emission rates of imageable photons. "Imaging with 134Ce-labeled radiopharmaceuticals have the potential to guide therapeutic dosing of the concomitant 225Ac-labeled molecule," write Dr. Bobba et al. "Encouragingly, the ex-vivo biodistribution of 134Ce/225Ac-Macropa-PEG4-YS5 demonstrated identical distribution in most tissues along with tumors with the exception of the liver and spleen. To our knowledge, this is the first report as a biochemical study comparing the biodistribution of Ce-134 and Ac-225, starting from chelators to tumor-targeting vectors."

Dr. Bobba presented his research on May 23, 2023, at the International Symposium on Radiopharmaceutical Sciences (iSRS) annual meeting in Honolulu, Hawaii. He was selected as a recipient of a UCSF Radiology & Biomedical Imaging Surbeck travel award to attend the meeting. The award honors the memory of Sarah J. Nelson, PhD, an acclaimed UCSF Radiology research scientist and faculty member who passed away in 2019. The Surbeck travel awards aim to support non-faculty academics conducting research in imaging science who are traveling to a meeting for an invited presentation.

Development of 134Ce/225Ac theranostics for cancer treatment. 134Ce/La-PSMA-617 and Macropa-PEG4-YS5 are theranostic pairs for 225Ac-based radioligand therapies in prostate cancer models, to enable both imaging and treatment.