177Lu-RAD204

July 22, 2026: Radiopharm Theranostics (ASX: RAD; Nasdaq: RADX) reported updated interim Phase 1 results for RAD204, an investigational PD‑L1–targeted lutetium‑177 nanobody radiotherapeutic, in patients with advanced solid tumors after immunotherapy. In cohort 3 at the current highest dose level (90 mCi), two patients have been dosed and both remain on treatment and progression-free (a third patient is screening).

Efficacy (cohort 3): Patient 1 achieved a RECIST-confirmed partial response after cycle 2, with target-lesion reductions of 19% after dose 1, 43% after dose 2 (PR), 43% maintained after dose 3 (confirmed PR), and 35% after dose 4; the patient remains progression-free beyond seven months. Patient 2 showed early tumor shrinkage (7% reduction) after the first cycle and remains progression-free.

Safety: Across dose levels 1–3, no dose-limiting toxicities have been observed. Kidney uptake was reported as limited (8.1 Gy cumulative across four cycles in Patient 1), and the company said this does not preclude escalation to dose level 4.

The Phase 1 study’s primary goal is to establish the recommended Phase 2 dose; additional data updates are anticipated to inform a planned Phase 2 trial.