Radiopharm Theranostics (ASX: RAD, NASDAQ:RADX, "Radiopharm" or the "Company"), a clinical-stage biopharmaceutical company focused on developing innovative oncology radiopharmaceuticals for areas of high unmet medical need, today announced that it has dosed the first patient in the second cohort of its First-In-Human (FIH) Phase 1/2a clinical trial of RV-01 (177Lu-Betabart) in patients with B7-H3 expressing tumors. This follows a positive recommendation from the Safety and Monitoring Committee (SMC), an independent multidisciplinary committee, to advance to the 70 mCi dose of RV-01.

RV-01 is a 177Lutetium-tagged engineered monoclonal antibody, designed with a strong affinity for the 4Ig isoform of B7-H3. B7-H3 is an immune checkpoint molecule that is overexpressed across several tumor types and has emerged as a compelling target for antibody-based cancer immunotherapy. Multiple preclinical studies with RV-01 have shown tumor shrinkage and prolonged survival in animals treated with the radiotherapeutic agent.

The Phase 1/2a clinical trial is a dose escalation and expansion trial designed to evaluate the safety, biodistribution, radiation dosimetry and preliminary anti-tumor activity of RV-01 in B7-H3 expressing tumors. The trial will determine the recommended dose of RV-01 to move forward in future studies. The Phase 1/2a study is currently being conducted at clinical centers across the U.S.