PFBH-21

PFBH-21 is a humanized antibody-drug conjugate (ADC) targeting B7-H3 (CD276), developed in collaboration with Duality Biologics. It consists of a humanized anti-B7-H3 monoclonal antibody conjugated to a topoisomerase I inhibitor payload via a cleavable linker, with a drug-to-antibody ratio (DAR) of approximately 6. PFBH-21 is being investigated for the treatment of B7-H3-expressing solid tumors, particularly lung cancer and prostate cancer. Preclinical studies have also explored PFBH-21 as a theranostic platform by conjugating it with chelators like DFO or DOTA to enable radiolabeling with zirconium-89 ([89Zr]Zr-DFO-PFBH-21) for immunoPET imaging and lutetium-177 ([177Lu]Lu-DOTA-PFBH-21) for targeted radionuclide therapy.