Radiopharm Theranostics Doses First Patient in Tb-161 RAD 402 Phase 1 Prostate Cancer Trial

RADXRADX

Radiopharm Theranostics has dosed the first patient in its Phase 1 dose-escalation trial of RAD 402, a KLK3-targeting monoclonal antibody labeled with Terbium-161 for advanced prostate cancer. The company expects to report data from the two dose levels in the second half of 2026 after assessing safety, tolerability and biodistribution.

1. First-In-Human Dosing

Radiopharm Theranostics has dosed the first patient in its open-label Phase 1 trial of RAD 402 for advanced prostate cancer. The dose-escalation study will evaluate safety, tolerability, whole-body distribution and preliminary clinical activity to determine the maximum tolerated dose or recommended Phase 2 dose.

2. Innovative Radiotherapeutic Design

RAD 402 is an anti-KLK3 monoclonal antibody radiolabelled with Terbium-161 that leverages dual emission to target KLK3-expressing tumors. Preclinical mouse xenograft studies showed strong tumor uptake with minimal bone and marrow exposure and expected hepatic clearance consistent with antibody pharmacokinetics.

3. Upcoming Data Milestones

The company plans to report data from the first two dose levels in the second half of 2026. These results will inform dose escalation decisions and guide patient expansion in future trials.

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