Radiopharm reports preclinical Lu177-B7H3-mAb data

Radiopharm (RADX) Theranostics announced that preclinical data from studies with the Lu177-B7H3-monoclonal antibody RV01 demonstrated favourable biodistribution and showed that RV01 maintained high tumour uptake. In addition, the Fc region modifications of the monoclonal antibody confirm a shorter half-life, compared to traditional mAbs. The shorter half-life and other Fc modifications have the potential to limit off-target exposure to the isotope and mitigate toxicities associated with traditional monoclonal antibody therapies. RV01 is the Company’s B7-H3-targeted radiopharmaceutical therapy designed with strong affinity for the 4Ig isoform of B7H3 that is highly expressed in tumours and not in healthy tissues, which is being developed in partnership with MD Anderson Cancer Center. The B7-H3 targeting monoclonal antibody is designed to target various solid tumours that express the B7-H3 protein. High expression of this target is associated with a poor prognosis in many cancer types. The new preclinical data corroborate conclusions from earlier preclinical mouse studies that identified a high-affinity antibody highly selective to the cancer-specific 4Ig isoform of the B7-H3 receptor, demonstrated complete regression of established solid tumours with treatment and showed promising evidence of immune system stimulation and the ability to confer immune memory.