Phase I/IIa clinical trial of 68Ga-PSMA-11 synthesized by a newly developed automated module using cyclotron-generated 68Ga.

OBJECTIVE

This Phase I/IIa study evaluated the safety, pharmacokinetics, internal radiation dosimetry, and image quality of cyclotron-produced ⁶⁸Ga-PSMA-11 synthesized using an automated module in a Japanese population.

METHODS

In this single-center trial, nine Japanese men (3 healthy volunteers, 6 prostate cancer patients) received a single intravenous injection of ⁶⁸Ga-PSMA-11 (4.0 MBq/kg). Safety, pharmacokinetics (blood/urine), and internal radiation dosimetry (serial PET/CT) were assessed. Diagnostic performance was evaluated by lesion detection rates and image quality by quantitative metrics, including noise-equivalent count (NEC), to optimize the protocol.

RESULTS

No adverse events were observed. The automated synthesis process consistently yielded high-quality ⁶⁸Ga-PSMA-11, with a decay-corrected radiochemical yield of 2841 ± 584 MBq and a radiochemical purity > 99%. The kidneys received the highest absorbed dose, with an effective dose comparable to that reported in published data. The agent demonstrated rapid clearance, primarily via renal excretion (58.99% ± 11.34% in 6 h), with a biological half-life of approximately 3.8 h in whole blood. All histopathology-confirmed primary lesions were detected. Quantitative analysis indicated that high image quality was maintained even with substantially reduced acquisition times.

CONCLUSIONS

Cyclotron-produced ⁶⁸Ga-PSMA-11 is safe and exhibits favorable pharmacokinetics and dosimetry in a Japanese population. This exploratory Phase I/IIa trial suggests that the production method appears feasible.

TRIAL REGISTRATION: jRCT2022230014.