Radiopharm Theranostics and Cyclotek Sign Clinical Supply Agreement for ¹⁶¹Tb-KLK3-mAb Phase I Clinical Trial in Australia

RAD 402 preclinical data package complete; demonstrates safety and promising biodistribution profile

Ethics approval and Phase 1 clinical trial start in prostate cancer anticipated in 2H 2025

SYDNEY and BUNDOORA, Australia, June 24, 2025 (GLOBE NEWSWIRE) -- 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 the signing of a supply agreement with Cyclotek to radiolabel RAD 402 with Terbium-161 (¹⁶¹Tb) in Australia, which supports the initiation of a Phase 1 clinical trial. RAD 402 is an anti-Kallikrein Related Peptidase 3 (KLK3) monoclonal antibody radiotherapeutic labelled with the radionuclide ¹⁶¹Tb for treatment of prostate cancer.

“This agreement is an important milestone for the development of RAD 402 and is the last step needed to submit for ethics approval and begin our Phase 1 clinical trial in prostate cancer,” said Riccardo Canevari, CEO and Managing Director of Radiopharm Theranostics. “We are very appreciative of the entire team at Cyclotek for their support as we work together to bring an innovative new treatment option to patients battling prostate cancer.”

RAD 402 has been designed to target KLK3, which is highly expressed in the prostate, with very limited/no expression in other tissues and organs. Compared to ¹⁷⁷Lu, ¹⁶¹Tb emits additional Auger and conversion electrons alongside its β-radiation, which can lead to potentially improved antitumoral therapeutic efficacy. ¹⁶¹Tb-RAD 402 is the first company-sponsored Phase I trial in prostate cancer using ¹⁶¹Tb.

Under the agreement, Cyclotek will produce and provide doses of ¹⁶¹Tb-labeled RAD 402 to support Radiopharm’s upcoming Phase 1 clinical trial in prostate cancer in Australia. The Phase 1 trial is anticipated to start in the second half of 2025.

“We are pleased to partner with Radiopharm to facilitate the development of their innovative radiotherapeutic, RAD 402, for the treatment of prostate cancer,” stated Greg Santamaria, CEO of Cyclotek. “Our mission at Cyclotek is to improve the accessibility of radiopharmaceuticals to enhance patient outcomes. As we support the Radiopharm Theranostics team, we look forward to RAD402 advancing toward market approval while demonstrating the value radiotherapeutics can bring to patients.”